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Archive for the ‘Exalting Archosauria’ Category

(John: here’s a guest post from my former PhD student, soon to be 100% legit PhD, Dr., and all that jazz, Julia Molnar!)

This is my first guest post, but I have been avidly following what’s in John’s freezer (and the blog too) for quite a while. I joined the lab in 2009 and left a month ago on the bittersweet occasion of surviving my PhD viva (oral exam/defense), so I’d like to take a moment here to thank John and the Structure & Motion Lab for a great 4 years!

Moving on to freezer-related matters; specifically, a bunch of frozen crocodile spines. It was late 2011, and the reason for the spines in John’s freezer was that John, Stephanie Pierce, and I were trying to find out more about crocodile locomotion. This was anticipated to become my first major, first-author research publication (but see my Palaeontologia Electronica paper on a related subject), and I was about to find out that these things seldom go as planned; for example, the article would not be published for more than three years (the research took a long time!). Before telling the story of how it lurched and stumbled toward eventual publication, I’ll give you some background on the project.

Stomach-Churning Rating: 3/10; x-ray of dead bits and nothing much worse.

A stumbly sort-of-bounding crocodile. They can do better.

First of all, why crocodiles? For one thing, they’re large, semi-terrestrial animals, but they use more sprawling postures than typical mammals. Along with alligators and gharials, they are the only living representatives of Crocodylomorpha, a 200+ million year-old lineage that includes wolf-like terrestrial carnivores, fish-like giants with flippers and a tail fin, even armored armadillo-like burrowers. Finally, crocodiles are interesting in their own right because they use a wide variety of gaits, including bounding and galloping, which are otherwise known only in mammals.

Nile croc

Nile crocodile skeletal anatomy

OK, so why spines? Understanding how the vertebral column works is crucial to understanding locomotion and body support on land, and inter-vertebral joint stiffness (how much the joints of the backbone resist forces that would move them in certain directions) in particular has been linked to trunk movements in other animals. For this reason, vertebral morphology is often used to infer functional information about extinct animals, including dinosaurs. However, vertebral form-function relationships have seldom been experimentally tested, and tests on non-mammals are particularly scarce. So we thought the crocodile spines might be able to tell us more about the relationship between vertebral morphology, mechanics, and locomotion in a broader sample of vertebrate animals. If crocodile spine morphology could be used to predict joint stiffness, then morphological measurements of extinct crocodile relatives would have some more empirical heft to them. Several skeletal features seem to play roles such as levers to mechanically stiffen crocodile spines (click to emcroc’en):

Croc vertebra-01

Anatomy of a crocodile vertebra

We decided to use a very simple technique that could be replicated in any lab to measure passive stiffness in crocodile cadavers. We dissected out individual joints were and loaded with known weights. From the movement of the vertebrae and the distance from the joint, we calculated how much force takes to move the joint a certain number of degrees (i.e. stiffness).

Julia w vertebra (480x640)

Me with crocodile vertebra and G-clamp

Xray

X-ray of two crocodile vertebrae loaded with a metric weight to calculate their joint’s stiffness

Afterwards, we boiled the joints to remove the soft tissues – the smell was indescribable! We took 14 measurements from each vertebra. All of these measurements had been associated with stiffness or range of motion in other studies, so we thought they might be correlated with stiffness in crocodiles also.

morphometrics

Some of the vertebral measurements that were related to stiffness

Despite my efforts to keep it simple, the process of data collection and analysis was anything but. I recall and exchange with Stephanie Pierce that went something like this:

Stephanie: “How’s it going?”

Me: “Well, the data are messy, I’m not seeing the trends I expected, and everything’s taking twice as long as it was supposed to.”

Stephanie: “Yes, that sounds like science.”

That was the biggest lesson for me: going into the project, I had been unprepared for the amount of bumbling around and re-thinking of methods when the results were coming up implausible or surprising. In this case there were a couple of cool surprises: for one thing, crocodiles turn out to have a very different pattern of inter-vertebral joint stiffness than typical mammals: while mammals have stiff thoracic joints and mobile lumbar joints, crocodiles have stiffer lumbar joints. Many mammals use large lumbar movements during bounding and galloping, so crocodiles must use different axial mechanics than mammals, even during similar gaits. While that’s not shocking (they did evolve their galloping and bounding gaits, and associated anatomy, totally independently), it is neat that this result came out so clearly. Another unexpected result was that, although several of our vertebral measurements were correlated with stiffness, some of the best predictors of stiffness in mammals from previous studies were not correlated with stiffness in crocodiles. The study tells a cautionary tale about making assumptions about extinct animals using data from only a subset of their living relatives or intuitive ideas about form and function.

Finally, the experience of doing the experiments and writing the paper got me interested in other aspects of crocodilian functional anatomy. For instance, how does joint stiffness interact with other factors, such as muscle activity and properties of the ribs, skin, and armor in living crocodiles? Previous studies by Frey and Salisbury had commented on this, but the influence of those factors is less tractable to experiment on or model than just naked backbones with passively stiff joints. In the future, I’d like to study vertebral movements during locomotion in crocodiles – especially during bounding and galloping – to find out how these patterns of stiffness relate to movement. In the meantime, our study shows that, to a degree, crocodile backbone dimensions do give some clues about joint stiffness and locomotor function.

To find out more, read the paper! It was just featured in Inside JEB.

Julia Molnar, Stephanie Pierce, John Hutchinson (2014). An experimental and morphometric test of the relationship between vertebral morphology and joint stiffness in Nile crocodiles (Crocodylus niloticus). The Journal of Experimental Biology 217, 757-768 link here and journal’s “Inside JEB” story

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And I post my blog and stare
Into x-rays of an ostrich
I’ve always known that radiographs never lie
People always say “that’s cool”
To see x-rays of an ostrich
So keen to know what
Lies behind the skin

(evolved from “Eyes of A Stranger” by Queensrÿche, from the epic masterpiece of Operation: Mindcrime (1988). One of my favourite albums of all time, and a fantastic concept album too. The band was operating at their peak. Tight! Drug addict Nikki gets brainwashed by the evil Dr. X and made to assassinate a nun, Sister Mary, who was a prostitute, and then there’s like a revolution or something, and things get all screwed up and no one ends up happy – or alive. All the while, Geoff Tate is singing his guts out. Anyway, I got to see them play the whole album live in 1990 in Madison, WI, for the filming of Operation: Livecrime, which was like a Mecca moment for me back then. Look for me (pre-bald years) in about the 6th row. )

What does that album have to do with the number 2 (two days left in Freezermas)? Hmm… Track 2 is the instrumental Anarchy-X, and today’s post is about X-rays as well as that funky ostrich (2 legs good! 2 toes good, too!) again, so I’m satisfied, and by this point you’re probably just oggling the mind-blowing images below anyway, so fuck it!

Stomach-Churning Rating: 2/10; just X-rays.

Tech/MRes Kyle Chadwick, Renate Weller and the equine imaging team at the RVC took these x-rays of our birdie for us and for an artist who is doing a big x-ray animal art show (more news on this soon!)– thanks to all of them for some truly awesome images! I could stare at the intricate details in these images for hours– go ahead, do it. Click to emostrichinate them (this post needs to be viewed on nice big screen), and oggle away…

Head and neck.

Head and neck.

Another view of the same.

Another view of the same. The highly flexible esophagus and trachea can be seen going diagonally across the neck; twisting from ventral to dorsal. It’s floppy, so it can do that.

Neck near the head; tapering.

Neck near the head; tapering.

Middle of neck. Check out the rings of the trachea!

Middle of neck. Check out the rings of the trachea!

Base of neck and shoulder

Base of neck and shoulder.

Shoulder and chest. Hard to image; thick and dense (still was frozen).

Shoulder and chest. Hard to image; thick and dense (still was frozen), hence the whiteout toward the left side of the image.

Check out that wing!!

Check out that wing!!

Ankle- note the big calloused pad that ostriches rest on (right side of image).

Ankle- note the big calloused pad that ostriches rest on (right side of image).

That two-toed foot... but did you know that normally the missing 2nd toe is still there as a fibrous remnant on the 3rd toe?

That two-toed foot… but did you know that normally the missing 2nd toe is still there as a fibrous remnant on the 3rd toe?

Tomorrow: the final day of Freezermas. What will it be?

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Freezermas continues! Today we have a treat for you. Lots of detailed anatomy! This post comes from my team’s dissections of an ostrich last week (~3-7 February 2014), which I’ve been tweeting about as part of a larger project called the Open Ostrich.

However, before I go further, it’s as important as ever to note this:

Stomach-Churning Rating: 9/10: bloody pictures of a dissection of a large ostrich follow. Head to toes, it gets messy. Just be glad it wasn’t rotten; I was glad. Not Safe For Lunch!

If the introductory picture below gets the butterflies a-fluttering in your tummy, turn back now! It gets messier. There are tamer pics in my earlier Naked Ostriches post (still, a rating of 6/10 or so for stomach-churning-ness there).

All photo credits  (used with permission) on this post go to palaeoartist Bob Nicholls (please check out his website!), who got to attend and get hands-on experience in extant dinosaur anatomy with my team and Writtle College lecturer Nieky VanVeggel (more from Nieky soon)!

Research Fellow Jeff Rankin, myself and technician/MRes student Kyle Chadwick get to work.

Research Fellow Jeff Rankin, myself and technician/MRes student Kyle Chadwick get to work, removing a wing.

This is a male ostrich, 71.3 kg in body mass, that had gone lame in one foot last summer and, for welfare reasons, we had to put down for a local farmer, then we got the body to study. We took advantage of a bad situation; the animal was better off being humanely put down.

The number for today is 6; six posts left in Freezermas. But I had no idea I’d have a hard time finding a song involving 6, from a concept album. Yet 6 three times over is Slayer’s numerus operandi, and so… The concept album for today is Slayer’s  1986 thematic opus “Reign in Blood” (a pivotal album for speed/death metal). The most appropriate track here is the plodding, pounding, brooding, then savagely furious “Postmortem“, which leads (literally and figuratively, in thunderous fashion) to the madness of the title track, after Tom Araya barks the final verse:

“The waves of blood are rushing near, pounding at the walls of lies

Turning off my sanity, reaching back into my mind

Non-rising body from the grave showing new reality

What I am, what I want, I’m only after death”

I’m not going to try to reword those morbid lyrics into something humorous and fitting the ostrich theme of this post. I’ll stick with a serious tone for now. I like to take these opportunities to provoke thought about the duality of a situation like this. It’s grim stuff; dark and bloody and saturated with our own inner fears of mortality and our disgust at what normally is politely concealed behind the integumentary system’s viscoelastic walls of keratin and collagen.

But it’s also profoundly beautiful stuff– anatomy, even in a gory state like this, has a mesmerizing impact: how intricately the varied parts fit together with each other and with their roles in their environment, or even the richness of hues and multifarous patterns that pervade the dissected form, or the surprising variations within an individual that tell you stories about its life, health or growth. Every dissection is a new journey for an anatomist.

OK I’ve given you enough time to gird yourself; into the Open Ostrich we go! The remainder is a photo-blog exploration of ostrich gross anatomy, from our detailed postmortem.

(more…)

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Here, I give you a long-planned post on the patella (“kneecap bone”) of birds, which was my Royal Society Senior Research Fellowship sabbatical project for 2012-13. This is only a brief introduction to the anatomical issues at hand, err, I mean at knee…

Stomach-Churning Rating: 6/10; mostly skeletons/fossils, but there are a few images of the dissection of a guineafowl, which is fresh and meaty.

Archaeopteryx, the Berlin specimen. Helluva fossil, but nary a patella!

Archaeopteryx, the Berlin specimen. Helluva fossil, but nary a patella!

The question I am exploring, first of all, is simply how the patella evolved, because it seems to be present in almost all living birds. However, it is absent in all non-avian dinosaurs, and indeed most Mesozoic birds, too. There is barely a hint of any precursor structure (a “patelloid”) in other reptiles, but lizards evolved their own patella that is quite different (a flattened lozenge, not a rectangular structure lying tightly confined in a “patellar groove” on the femur as it is in birds). Mammals evolved the knobbly, hemispherical kind of kneecap that we’re familiar with, possibly on several occasions (a different story!). So the patella evolved at least three times in the lizard, mammal and bird lineages– and possibly more than once in each of these groups. And that’s about it for almost 400 million years of tetrapod evolution, except for a few very rare instances in fossils and sort-of-patella-like things in some frogs or other weirdos.

Fossil birds exhibit no clear presence of a patella until we come very close to modern birds on the avian stem of the tree of life (see below). And then, suddenly in modern birds, there is a lot of variation and not much good documentation of what kind of patella exists. This makes it challenging to figure out if the patella is ancient for modern birds or if it evolved multiple times, or how it changed after it first evolved– let alone bigger questions of what the patella was “for” (performance benefits, functional consequences, etc.; and developmental constraints) in the birds that first evolved it.

Considering that the patella is such an obvious bone in some birds, and certainly affects the mechanics of the knee joint (forming a lever for the muscles that cross it; homologous to our quadriceps muscles) and hence locomotion, it is a compelling research topic for me.

What follows is a pictorial guide to the patella of some birds, in sort of an evolutionary/temporal sequence (see my earlier post for a recap of some major groups), with a focus on animals I’ve studied more intensively so far (with >10,000 species, there is a lot that could be done):

Gansus, IVPP V15080
The early Cretaceous bird Gansus (from the IVPP in Beijing), represented by many beautifully preserved specimens, all of which lack a patella. This absence is characteristic of other stunningly preserved fossil Chinese birds, indicating that this is almost certainly an ancestral absence of a patella, until…

The famed Cretaceous diving (flightless) bird Hesperornis, from Wikipedia/Smithsonian.  Note the massive, conical/crested patella in front of the  knee (jutting up and overlapping the ribs/vertebrae close to the pelvis; see also below). That elongate patella is characteristic of many diving birds that use foot-propelled swimming; it has evolved many times in this fashion. Other hesperornithiform birds show some transformational states in their anatomy toward this extreme one.
Hesp-patella

Check this out! More Hesperornis (cast), with the femur on the left and the patella on the right. The bloody patella is almost as long as the femur! That’s nuts. With kind permission from the Natural History Museum, London.

Exhibited ostrich skeleton in left side view showing the patella (white arrow).
Exhibited ostrich (Struthio camelus) skeleton in left side view showing the patella (white arrow), on exhibit atThe Natural History Museum at Tring, Hertfordshire, UK. Ostriches are remarkable in that they have this elongate patella (actually a double patella; there is a smaller, often-overlooked second piece of bone) and yet are rather basal (closer to the root of the modern avian family tree)– however, they obviously are specialized in ways other than this double patella, most notably their very large size, flightlessness, and elongate legs. So the unusual patella is more likely linked to their odd lifestyle than a truly primitive trait, at least to some degree (but stay tuned: what happened with the patella in other members of their lineage, the ratites/palaeognaths, is much less well understood!).
Note that ostriches and Hesperornis together hint that the presence of a patella might have been an ancestral trait for living birds, but their patellae are so different that the ancestral state from which they evolved must have been different, too; perhaps simpler and smaller. Hence we need to look at other birds…
Skinned right leg of guineafowl, Numida meleagris.
Skinned right leg of a Helmeted Guineafowl, Numida meleagris, above. That whitish band of tissue in the middle of the screen, on the front of  the knee, is part of what is concealing the patella. That is an aponeurosis (connective tissue sheet, like a thin tendon) of the muscles corresponding to our “quads” or our tensor fascia latae, detailed more below. Guineafowl are fairly basal and well-studied in terms of their bipedal locomotion, so they are an important reference point for avian form and function.
Right guinefowl leg, with patella semi-exposed.
Right guineafowl leg, with patella exposed. Here I’ve peeled away that white band of tissue  and associated muscles, which have been reflected toward the bottom of the screen (AIL and PIL labels corresponding to the anterior and posterior parts of the Iliotibialis lateralis muscle). The tip of the scalpel is contacting the patella. It’s not much to see, but lies atop the bright yellow fat pad that cushions it against the femur. You should be able to see a groove in the end of the femur just above that fat pad, which is where the patella sits and slides up and down as the knee moves/muscles contract. This is called the patellar groove, or sulcus patellaris.
Left leg of a guineafowl (with right tibiotarsus behind it) showing both patellae in articulation; in medial (inside) view. The  patella is the little rectangular bit of bone in the top middle of the screen, interposed between femur and tibiotarsus.
Left leg of another guineafowl (with right tibiotarsus behind it, on the left) showing the patellae in articulation; in medial (inside) and cranial (front) views, respectively. The patella is the little rectangular bit of bone in the top middle of the screen, interposed between femur (thigh) and tibiotarsus (shank). With kind permission from the Natural History Museum, London.  
Penguin-patella
Right leg of a Cape Penguin (Spheniscus demersus) from the University Museum of Zoology in Cambridge, showing the big lumpy patella in this wing-propelled diver. They still walk long distances on land, so presumably a patella plays some role in their gait, helping to explain its large size, which like the ostrich and Hesperornis seems to be a novel trait. Notice the groove across the patella, made by the tendon of the ambiens (like our sartorius/”tailor’s muscle”), which crosses from the inside to the outside of the leg via this route. This groove is often considered a useful phylogenetic character in modern birds, as its contact with the patella (sometimes via a hole, or foramen) varies a lot among species.
Buceros skeleton UMZC
A hornbill, Buceros sp., from the UMZ Cambridge museum as well. This displays the possibly-more-typical, little rounded patellar nubbin that many birds have. See below for more.

Buceros knee closeupCloseup of the knee/patella of the hornbill, Buceros sp., from above. Not much to squawk about, patella-wise, but it’s there.

And so we complete our quick tour of the avian patella, in its grand variation and humble beginnings.

Why does an ostrich have a patella and a Tyrannosaurus, Edmontosaurus or Triceratops did not? Why were birds the only bipedal lineage to evolve a patella (mammals and lizards gained a patella as small quadrupeds), and why did some bipeds like kangaroos “lose” (reduce to fibrous tissue, apparently) their patella?

These are the kinds of mysteries my group will now be tackling, thanks to a generous Leverhulme Trust grant on sesamoid bone ontogeny, mechanics and evolution.  My group is now Dr. Vivian Allen as the postdoc, Sophie Regnault as the PhD student, and Kyle Chadwick as the technician and MRes student, along with numerous collaborators and spin-off projects. We’re looking forward to sharing more! But for now, I hope that I’ve engendered some appreciation for the avian patella, as the silly title indicates (“fella” used in the general sense of anyone!). This work is all unpublished, but some of this should be out in not too long, in much more lavish detail! Much as the patella is the “forgotten lever “of the avian hindlimb, it is the fulcrum about which a substantial part of my research group’s activity now pivots.

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Yesterday I encountered the question that, as a scientist who has studied a certain chunky Cretaceous carnivore a lot, most deflates me and makes me want to go study cancer therapeutic methods or energy sources that are alternatives to fossil fuels (but I’d be useless at either). I will explain why this is at the end of the post.

The question stems from a new discovery, reported in Proceedings of the National Academy of Sciences (PNAS) and thus expected to be one of the more important or exciting studies this year (no, I’m not going to get into the issue here of whether these “high impact” journals include the best scientific research or the most superficial or hyped “tabloid” science; they publish both, and not in mutual exclusivity). It’s a broken Tyrannosaurus rex tooth embedded in a duckbill dinosaur’s tail bone, which healed after the injury, showing that the animal survived the attack.

If you’re with me so far, you might be making the logical leap that this fossil find is then linked to the hotbed of furious controversy that still leaves palaeontology in crisis almost 100 years after Lambe suggested it for the tyrannosaur Gorgosaurus. If the hadrosaur survived an attack from a T. rex, then T. rex was a habitual predator and OMG JACK HORNER AND OTHERS BEFORE HIM WERE WRONG!

And you’d be right.

My encounter with the question stemmed from an email from a science journalist (Matt Kaplan) that, as is normal practice, shared a copy of the unpublished paper and asked for comments from me to potentially use in an article he was writing for the science journal Nature’s news site. Here, then, was my off-the-cuff response:


“Ooh. I do have a pretty strong opinion on this. Not sure if you’d want to use it but here goes. I may regret it, but this hits my hot buttons for One of the Worst Questions in All of Palaeobiology!

The T. rex “predator vs. scavenger” so-called controversy has sadly distracted the public from vastly more important, real controversies in palaeontology since it was most strongly voiced by Dr Jack Horner in the 1990s. I find this very unfortunate. It is not like scientists sit around scratching their heads in befuddlement over the question, or debate it endlessly in scientific meetings. Virtually any palaeontologist who knows about the biology of extant meat-eaters and the fossil evidence of Late Cretaceous dinosaurs accepts that T. rex was both a predator and scavenger; it was a carnivore like virtually any other kind that has ever been known to exist.

While the discovery is nice evidence, it is not particularly exciting in a scientific sense and is only one isolated element from species that lived for hundreds of thousands of years, which to me changes nothing and allows no generalizations about the biology of any species, only the statement that at one point in time a Tyrannosaurus bit a hadrosaur that survived the encounter. There is no real substance to the controversy that T. rex was “either” a predator or scavenger. It is just something that scientists drum up now and then to get media attention. I hope that soon we can move on to more pressing questions about the biology of extinct animals, but the media needs to recognize that this is just hype and they are being played in a rather foolish way; likewise scientists that still feel this is an exciting question need to move on. Maybe this specimen will allow that. But somehow my cynical side leads me to suspect that this “controversy” will just persist because people want it to, regardless of logic or evidence. (bold font added; see below)

Great galloping lizards, I am so tired of this nonsense. Maybe there is educational value in showing how science deals with provocative half-baked ideas about celebrity species, but scientists in the community need to speak up and say what the real science is about. It’s not about this “controversy”. Modern palaeontology is so much better than this.

Sorry for the rant. Maybe it’s too extreme but I’m just fed up with this non-issue! I suspect a huge proportion of our field feels similarly, however.”


(I later redacted a bit of it where I got a little too excited and used the word “curmudgeon”; a mistake, as that could be seen as ad hominem rather than a term of endearment, and this issue is about the science and not the people, per se. That bit is redacted here, too. I’ve also redacted a sentence in which I made an opinion on whether the paper should have been published in PNAS; that is mostly irrelevant here. I was not a reviewer, and authors/reviewers/editors have to make that decision. This would be a massive tangent away from what this blog post is intended to be about! I know some of the authors and don’t want to offend them, but this is about the science and how it is represented to the world, not about these particular authors or even this paper itself.)

Importantly, Kaplan’s story did include my skeptical quote at the end. I am curious to see how many other news stories covering this paper go that far.

Would a T. rex prey on, or just scavenge, a giant chicken? (art by Luis Rey)

Would a T. rex prey on, or just scavenge — or have a great time racing — a giant chicken? (art by Luis Rey)

I will stop right here and acknowledge that I’ve published a lot on a somewhat related topic: how fast a T. rex could run or if it could run at all. To me, that’s a great scientific question that has consequences not only for the predator/scavenger false dichotomy, but also for general theories of locomotor biomechanics (can an animal the size of a large elephant run as well as or better than said elephant? What are the thresholds of size and maximal running/jumping/other athletic abilities and how do they vary in different evolutionary lineages? And so on.). I’ll defend the validity of that question to the bitter end, even if it’s a question I’ve grown a little (but only a little) tired of and generally feel is about as well settled as these things can be in palaeontology (see my review here). I’ll also defend that it has been a real controversy (I have plenty of old emails, formal rebuttals submitted by colleagues, and other discourse as evidence of this) since I tackled it starting in 2002 and sort of finishing by 2011. I am sensitive about the issue of hyping my research up– this is something I’ve been careful about. I set a reasonable bar of how much is too much, check myself continuously with reflective thought, and I do not feel I have ever really crossed that bar, away from science-promotion into darker realms. This is partly why I’ve stopped addressing this issue in my current work. I feel like the science we’ve done on this is enough for now, and to keep beating the same drum would be excessive, unless we discovered a surprising new way to address the questions better, or a very different and more compelling answer to them.

T. rex: scavenger or predator?” was controversial back  in 1994 when Horner published “The Complete T. rex”, where he laid out his arguments. Brian Switek covered this quite well in his post on it, so I will not review that history. There was a big Museum of the Rockies exhibit about it that toured the USA, and other media attention surrounding it, so Horner’s name became attached to the idea as a result. Other such as Lambe and Colinvaux had addressed it before, but their ideas never seemed to gain as much currency as Horner’s did. But this post is not about that.

What this post is about is a consideration of why this is still an issue that the media report on (and scientists publish on; the two are synergistic of course), if most scientists aware of past debates are in good agreement that a T. rex was like most other carnivores and was opportunistic as a switch-hitting scavenger-predator, not a remarkably stupid animal that would turn down a proper meal that was dead/alive. Indeed, the Nature news piece has a juicy quote from Horner that implies (although I do not know if it was edited or if important context is missing) that he has been in favour of the opportunistic predator-scavenger conclusion for some time. Thus, as Switek’s article notes, even the strongest advocates of the obligate scavenger hypothesis(?) have changed their minds; indeed, that 2011 blog post intimates that this had already happened at least 2 years ago.

For many years, nothing has been published in the main peer-reviewed literature that favours that extreme “obligate scavenger” hypothesis. If I am wrong and there is a scientific debate, where are the recent papers (say within the past 5 years) that are strong, respectable arguments in favour of it? I contend that it is a dead issue. And if it is just about the middle ground; i.e. what percent of its time did a T. rex spend hunting vs. scavenging; we have no clue and may never know, and it’s not a very interesting question.

But who then is feeding off of this moribund equine; this defunct tyranno-parrot?

In thinking about my reply to the journalist over the past 2 days, I am reminded again of my general feeling that this is no longer a question of scientific evidence; the important bit in bold font above. Maybe we just like this “hypothesis” or the “controversy”, or maybe we’re lazy and don’t want to have to hunt for real debates in science.

But who are “the people?” I do not feel that The Public should be blamed; they are the people that The Scientists and The Media ostensibly are seeking to inform about what the state of modern knowledge and uncertainty is in science. So when I get asked about the controversy after a public lecture, I always try to go into detail about it. I don’t sigh and say “go Google it”. Nor do I do this to a journalist. Indeed, I’ve generally headed this issue off at the pass and added a blurb to press releases/webpages explaining my T. rex research to explain how it relates to the non-controversy; example here.

I have to begin turning my finger of accusation away from scientists and toward some of the media, because they must play a huge role in the shennanigans. Yes, scientists should know better then to play this up as a valid, heated, modern controversy. That is true. Yet I have a feeling that the balance of blame should also fall heavily on the side of media (general and science news) that continue to report on this issue uncritically as a real controversy. Thus the general public thinks it still is, and scientists/journals keep issuing papers/press releases that it is, leading to more reporting on this “controversy”, and the beast refuses to die. Switek’s article is a good counter-example of balanced coverage with clear application of critical thinking.

This is trivially different from other non-controversies in palaeontology such as whether birds evolved from a subgroup of theropod dinosaurs and hence are dinosaurs by virtue of descent (consensus = yes). So it is reflective of a broader problem of not calling a spade a spade.

And it’s embarassing, to a scientist, as my quote above expressed, to see dead controversies trotted out again and again, feeding the public perception that they are not dead.

That’s what leaves me frustrated. When do the shennanigans end?

I am reminded of a quote from a Seinfeld episode:

“Breaking up is like knocking over a Coke machine. You can’t do it in one push. You gotta rock it back and forth a few times, and then it goes over.”- Jerry, from the episode “The Voice”.

But this predator/scavenger relationship-from-hell leaves me, as a specialist working in this general area, feeling like I am trapped under that fridge. Help!

That’s why I started off this long post talking about feeling deflated, or disappointed, when asked this question. I do feel that way. I have to admit, I sometimes even feel that way when a sweet young kid asks me that question. Deep inside, I wish they wondered about something else. I wish that science had reached them with a deeper, more contemporary question. But when a journalist asks me how I feel about a new paper that revisits the “controversy”, I feel embarassed for palaeontology. Can’t we get past this? It makes us look so petty, mired in trivial questions for decades. But we’re not like that. This is a dynamic, exciting, modern field, but every news story about non-issues in palaeontology just perpetuate bad elements of palaeontology’s image.

To the scientists– why don’t we put our foot down more and say enough is enough, this is a dead issue? We have a role not only in peer review, but also in communicating our views about published work to the media when asked (AND when not asked, as in this blog post). But if you call them on it, do they listen? Which brings me to…

To the media (science/general journalists etc; I know this is a huge category and please don’t think I am blaming 100% of journalists or assuming they are all the same; they are not!)– if scientists tell you that a “controversy” is not such, at what point do you accept their judgement and kill the story, or at least use that quote? Does that ever happen? In what way are you at the mercy of senior editors/others in such issues? What power do you have? Is a shift in the balance of editorial power needed, or even achievable, in your case or in good exemplar cases? I’d really like to hear your experiences/thoughts. I am sure there is a lot I am not understanding, and I know many journalists are in a tough situation.

To the public– You’re often being misinformed; you are the losers in this issue. How do you feel about all it? (While this post focuses on a very tiny issue, the T. rex scavenger/predator unending drama, it is also about a broader issue of how the media perpetuates controversies in science after they have already gone extinct.)

What did this post have to do with freezers? Nothing. I’m just (H)ornery. Although I was once filmed for a planned Discovery Channel film about scientists who find a frozen tyrannosaur in polar regions and have to decide what to do with it before it slips into a chasm and is lost forever. Probably better that this never aired; it was cancelled. Segue to this post.

The Berkeley cast of the Wankel (MOR555) specimen of T. rex. Will we ever see the end of the predator/scavenger non-issue?

The Berkeley cast of the Wankel (MOR555) specimen of T. rex. Will we ever see the end of the predator/scavenger non-issue?

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Less words, more pictures in this post, and I’ll get the one lame cake joke out of the way early. I’ve nearly finished my research blitz through the postcranial material of the NHM-Tring’s osteological collection and have made some pit-stops for cake skulls now and then when I see one that pleases me. Now I shall present a survey of some of the species I’ve examined. I’ll proceed up from the base of the crown clade of living birds (Neornithes/Aves; the most recent common ancestor of living birds and all its descendants) and first take a tour of Palaeognathae; the ratites and kin; then move another step up into the Neognathae, first featuring the lineage featuring the ground fowl (Galliformes) and then the waterfowl (Anseriformes). If all this taxonomy and phylogeny is a bit much, check out this page for a brush-up on the bushy branches of bird biodiversity.

First, lots of bones of our cast of currasows, chachalacas, cassowaries and other kooky characters. And then, perhaps, a stop to the excessive alliteration. Finally, I will finish with some examples of species oddity (hat tip to Chris Hadfield).

Stomach-Churning Rating: 2/10- some bony pathologies but still just dry bones. Minimal cake jokes, and no filthy swearing this time.


BRING ON THE BONES:

Exploded skull of an ostrich/ This takes skill.

Exploded skull of an ostrich, Struthio camelus. This kind of careful preparation takes crazy skill, and creates a thing of rare beauty.

Neat skull of a cassowary, Casuarius casuarius.

Imposing skull of a cassowary, Casuarius casuarius, with a rather worn head casque.

Mummified Owen's Little Spotted kiwi, Apteryx owenii.

Mummified Owen’s Little Spotted Kiwi, Apteryx owenii. The feathers were still soft and fluffy, but I would not call this specimen cuddly.

Dorsal view of the back/hips of the Great Spotted kiwi, Apteryx haasti.

Dorsal view of the back/hips of the Great Spotted Kiwi, Apteryx haasti. I like this photo and am not sure why. The symmetry and shading pleases me, I guess.

Front view of the back/hips of the Great Spotted kiwi, Apteryx haasti.

Front view of the back/hips of the Great Spotted Kiwi, Apteryx haasti, watching over my laptop and watching me while I write this blog on my laptop… so meta(ornithine)!

Wing of a kiwi, showing the fragile bones and feather attachments.

Wing of a kiwi, showing the fragile bones and feather attachments. “Apteryx” = “no wings”… well not quite. Click to emkiwi(?) so you can identify the individual bones, from the humerus right down to the fingers! I love this specimen.

The left leg (in front view) of the elephant-bird, Aepyornis maximus, from Madagascar, with a small moa nearby in left side view.

The titanic left leg (in front view) of the Elephant Bird, Aepyornis maximus, from Madagascar, with a small moa nearby in left side view. There’s so much awesomeness about elephant birds I don’t know where to start, but this is one good place to do so.

Mummified Unulated tinamou, Crypturellus undulatus.

The smaller end of the palaeognath scale: a mummified Undulated Tinamou, Crypturellus undulatus. Somehow the head got stuck into the abdominal cavity underneath the sternum, so this tinamou almost had its head up its arse. A tinamou with head in its proper position looks and sounds like this (video).

And now we take a left turn into the Galloanseres, most basal branch of the neognath birds, to see some of the neglected, strange early branches off from the “main line” that led to the modern diversity of ducks, geeses and swans (Anatinae, Anserinae).

Screamers (Anhimidae) are to Anseriformes as megapodes (see below; brush turkeys) are to Galliformes. By that I mean that both screamers and megapodes are very early branches off the main line of their respective lineages’ evolution, and both are quite strange when seen in that context… an unfair one, frankly; over-focused on the most familiar, “modern” or most speciose group. More about this issue further below.

This was my first hands-on experience with screamer anatomy; I was familiar from reading Tetrapod Zoology and other material about them. Check out the sound that gives them their name here! I’m now a big fan- they have so many strange features: oddly chunky but often very light bones, big feet with long toes, and then these switchblade-wrists, which would make Batman jealous:

Crested screamer, Chauna torquata, showing the wicked spur on the carpometacarpus.

Crested Screamer, Chauna torquata, showing the wicked spur (and smaller one) on the carpometacarpus.

Horned screamer, Anhima cornuta; similar carpometacarpal spur as in Chauna.

Horned Screamer, Anhima cornuta; similar carpometacarpal spurs as in Chauna.

Torso of a screamer seen in top view. Nice narrow body.

Torso of a screamer seen in top view. Nice narrow body, and no uncinate processes (spur-like bony struts that cross the ribs and act as levers for the muscles that move the ribcage during breathing)

The long, gracile, clawed toes of a screamer.

The long, gracile, clawed toes of a screamer. Those toes, especially as they belong to an animal called a screamer, are spooky for me. Note also: very little toe-webbing for a “waterfowl.”

Not to be outdone, on the Galliformes side of Galloanserae, we have some funky headgear in the Maleo (a megapode bird/Megapodiidae; a very basal branch of “brush turkeys” and kin) and curassows (part of the Cracidae; odd South American birds whose males make booming sounds, presumably using their head-casques as resonating chambers?):

Skull of a male maleo, Macrocephalon maleo.

Skull of a male Maleo, Macrocephalon maleo. AR Wallace famously pursued it, and here is its funky call.

Australian brush-turkeys, Alectura lathami i, at the Alma Park Zoo near Brisbane, Australia; they run wild there. Here they are doing what they are best known for: making a mound-like nest.

Australian brush-turkeys, Alectura lathami, at the Alma Park Zoo near Brisbane, Australia; they run wild there. Here they are doing what they are best known for: making a mound-like nest. We were doing kangaroo biomechanics experiments and they were everywhere. I was in awe to see such exotic (to me) birds; locals seemed not so enthused (the birds are loud and make a lot of mess).

Skull of Helmeted curassow, Crax/Pauxi pauxi.

Skull of Helmeted Curassow, Crax/Pauxi pauxi,  showing that resonating chamber. Along with this boom-boom-room, the male uses a piece of food that he holds to draw in the female; if she takes it, then it’s sexy time.

Foot of a Russian Black Grouse, Tetrao tetrix (nothing to do with a certain videogame), with and without flesh.

Foot of a Siberian Black Grouse, Tetrao tetrix (nothing to do with a certain videogame), with and without flesh. Regard the broad, feathered feet, well insulated and with plenty of surface area for prancing around in the snow or moorlands. Tetrao engage in a cool display pattern called lekking, in which the males group together and show off to watching females.

A theme in the section above that is not to be missed is that there is some amazing disparity of anatomical forms in these basal lineages of poultry-relatives. Don’t dismiss the Galloanserae as just boring food-birds! Heaps of not-so-well-studied species exist here, surely with a treasure trove of cool neontological and evolutionary questions waiting for the right person to ask! Darwin’s chickens may get their share of neglect, but that pales in comparison to how little we understand about many basal Galloanserae.

What a lot of people think of as a “ground fowl” or galliform way of life is more of a way of life somewhat typical of the Phasanidae- chickens, pheasants and their familiar kin. Megapodes, curassows, guans, grouse and other Galliformes do not necessarily do things in the “typical” ground fowl way, much as the earlier branches of the Anseriformes don’t always look/act like “proper water fowl” (i.e. Anatidae). The phenomenon at play here is one of the great bugaboos in biology: essentialism– the often implicit misconception that variation away from some abstract ideal is negligible, uninteresting or just not conceivable due to mental blinders. When we say something like “the chicken is a fascinating species” we are sliding down the essentialistic slope. There is no “the chicken.” Not really. Oh dear, speaking of slippery slopes, I’d best stop here before I start talking about species concepts. And no one wants that to happen! Anyway, essentialism still pervades a lot of modern scientific thinking, and has its place as a conceptual crutch sometimes. But in biology, essentialism can be very insidious and misleading. It burrows in deep into the scientific mind and can be hard to root out. Unfortunately, it is entrenched in a lot of science education, as it makes things easier to teach if you sweep aside the exceptions to the essentialist “rules” in biology. I catch myself thinking in static, essentialist ways sometimes. The punishment is no cake for a week; so awful. :)

And speaking of “normal” or “typical,” morphology is of course often not that way even within a species, age class or gender. Pathology is a great example; by definition it is abnormal. It is a shattering of the “essence” of animals, brought on by some malady.

Next I’ve highlighted some of the amazing pathologies I’ve seen in the Tring skeletons. There have been so many I’ve been unable to keep track of them– some of these birds had the stuffing beaten out of them, and I’m not talking about Thanksgiving turkeys. Some were captive animals, in which the pathology might be blamed on living an inappropriate environment, but some were wild-caught — given the extreme pathologies, it’s a wonder those even survived to be found, but perhaps less a surprise that they were caught.


BONES GONE BONKERS:

View of left knee of a specimen of the Highland guan, Penelopina nigra, showing some nasty osteoarthritis around the whole joint.

View of left knee of a specimen of the Highland Guan, Penelopina nigra, showing some nasty osteoarthritis around the whole joint. Eew.  A happier Guan sounds like this.

Femora and tibiae of the Blue-throated Piping Guan, Aburria cumanensis. Amazing pathology involving the left femur (broken, rehealed) and tibiotarsus (secondary infection?).

Femora and tibiotarsi of the Blue-throated Piping Guan, Aburria cumanensis. Amazing pathology involving the left femur (broken, rehealed) and tibiotarsus (secondary infection?). Interestingly, the non-fractured limb also showed some pathology, perhaps indicating general infection and/or arthritis in reaction to the severe damage to the other leg, or just increased load-bearing on that leg.

Little Chachalaca, Ortalis motmot, showing a broken and rehealed right femur and the tibiotarsus.

Little Chachalaca, Ortalis motmot, showing a broken and rehealed right femur and the tibiotarsus. As in the guan above, this animal was not walking for many weeks; its femur had snapped in two, but somehow melted back together. The tibiotarsus didn’t look too great, either; lumpy and bendy. In better times, the Chachalaca does the cha-cha like this.

These two specimens blew my mind. On the right is a normal Tetrao tetrix (Black grouse); on the left is one hybridized with another (unknown) species.

These two specimens blew my mind. On the left is a normal Tetrao tetrix (Black Grouse); on the right is one hybridized with another (unknown) species.

In the picture above, what amazed me first was the very unusual flattened pelvis/synsacrum of Tetrao, which characteristically is light and wide. But in the hybrid this morphology was completely gone; the pelvis had a more standard “galliform” (read: Phasianid)-like shape, deeper and narrower and more solid in build. I am guessing that the hybrid was a cross with a pheasant like Phasianus itself, whose anatomy would be more like this. Somewhere in here there is a fantastic evo-devo/morphometrics project waiting to happen.

That’s my quick specimen-based tour of “basal birds”. Beyond these two clades of Palaeognathae and Galloanseres, there lies the forebidding territory of Neoaves: much of living avian diversity, and extremely contentious in its phylogenetic relationships. I’m tackling them next for my research on the evolution of the patella/kneecap. But first, I’ll be at the NHM-Tring today for a whirlwind tour through the respectably speciose “normal” Galloanseres clades of Phasianidae and Anserinae+Anatidae, so off I go! (It’s my wife’s birthday celebration, so cake may have to wait for later this time)

So what do you think? What’s your favourite neglected “primitive” bird group (more apropos: early branching avian lineage that may still be very specialized, rare and poorly understood), or cool factoid about palaeognaths and basal neognaths?

No quaggas were harmed during the writing of this post.

No quaggas were harmed during the writing of this post. Polly wanna quagga?

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Bovids to the right of me, pinnipeds above, what's a guy to do but squee?

Bovids to the right of me, pinnipeds above, what’s a guy to do but squee?

I’ve been doing some osteological studies of the patella (bone in the major tendon in front of the knee; termed a sesamoid) that have included frequent visits to the Natural History Museum’s avian skeleton collection at Tring. It’s a cute little town, northeast of London, in the green county of Hertfordshire where I live and work. The museum at NHM-Tring is a great old school multi-storey display packed with skeletons and stuffed animals in dark wood cabinets, with many critters hanging from wrought iron railings or other suspensions above (see above). I blogged about the Unfeathered Bird exhibit (and book) that just finished up its tour there yesterday. And I’ll be blogging later, as I keep promising, about the cool things I’ve learned during the past year of my studies of the form, function, development and evolution of the patella.

As an aside, I heartily recommend doing research at the NHM-Tring. It’s away from the bustle (and arduous Tube trip) of the South Kensington NHM, and the curatorial staff are immensely helpful… and there is something else that makes the trip even more enjoyable, but you must read more below to find out about it.

Stomach-Churning Rating: 2/10; 150-year-old dry bones. But an advance warning to (1) diabetics and (2) pun-haters, for reasons that will become evident.

Dr Heather Paxton and Dr Jeffrey Rankin, postdoc researchers working on our collaborative BBSRC chicken biomechanics grant (see thechickenofthefuture.com), explain their science to an attentive Darwin.

Dr Heather Paxton and Dr Jeffery Rankin, postdoc researchers working on our collaborative BBSRC chicken biomechanics grant (see thechickenofthefuture.com), use the Structure & Motion Lab whiteboard to explain their science to an attentive Darwin.

Today I have a short pictorial exhibit of something wonderful I ran into while patellavating in the NHM collections. As often happens while doing museum research, I had a serendipitous encounter with a bit of history that blew my mind a little, and had me geeking out. These things happen because museum collections are stuffed with specimens that, to the right eyes or the right mindset, pack a profound historical whallop. As a scientist who is pretty keen on chickens (Gallus gallus), there are probably no museum specimens of chickens that would get me more excited about than the chickens Darwin studied in his investigations of artificial selection. In fact, most museum specimens of domestic chickens would not be that interesting to me, especially after seeing these ones.

Darwin wielded the analogy between artificial selection and his conceptual mechanism of natural selection in the first ~4 chapters of On the Origin of Species to clobber the reader with facts and try to leave them with no doubt that, over millennia, nature could craft organisms in vastly more complex and profound ways than human breeders could mould them over centuries. While people most often speak of Darwin’s pigeons when referring to Darwin and avians or artificial selection and variation, his chickens appear in The Origin and other writings quite often, too (most prominently, The Variation of Animals and Plants Under Domestication in 1868– more about that here). For example, from my 1st edition facsimile of The Origin from Harvard University Press, pp. 215-216:

Natural instincts are lost under domestication… It is not that chickens have lost all fear, but fear only of dogs and cats, for if the hen gives the danger-chuckle, they will run… and conceal themselves in the surrounding grass or thickets; and this is evidently done for the instinctive purpose of allowing, as we see in wild ground-birds, their mother to fly away. But this instinct retained by our chickens has become almost useless under domestication, for the mother-hen has almost lost by disuse the power of flight.”

Well told, Mr D!

I am also reminded of how chickens and Darwin have had darker relationships, such as this sad story. Or how evolution via Darwinian mechanisms crosses paths with pop culture in fowl ways, such as how tastes-like-chicken evolved, or how some say that chickens, over great periods of time, have been naturally selected in such a way that they are now heritably predisposed to cross roads, or that the amniote egg preceded the evolution of the genus Gallus by some 325+ million years. I see I am drifting and drifting further away from the topic at hand, so let me segue back to Darwin’s chickens. We’ll take this corridor there:

Inside the avian osteology collection at Tring. Sterlie at it might seem, places like this are  fertile breeding grounds for scientific discovery.

Inside the avian osteology collection at Tring. Sterile at it might outwardly seem, places like this are fertile breeding grounds for scientific discovery. And a sterile-looking collection means well cared-for specimens that will persevere for future discoveries.

So anyway, when museum curator Jo Cooper said to me something like “I have some of Darwin’s chickens out over on the other counter, do you want to have a look or shall I put them away?” my answer was quick and emphatic. YES! But only after lunch. I was hungry, and nothing stops me from sating that hunger especially when the sun is out and there are some fine pubs within walking distance! I settled on the King’s Arms freehouse, and had a delicious cheeseburger followed by a spectacularly good apple-treacle-cake with ice cream, expediently ingested while out on their sunny patio. Yum! I cannot wait to have that cake again. What a cake! Darwin’s bushy eyebrows would have been mightily elevated by the highly evolved flavour, which would have soothed his savage stomach ailments. He would have been like:

Damn, Emma! Holy s___ this is great apple-cake; here, try some! There is grandeur in this tasty cake, with its several flavours, having been originally cooked into a few baking trays or into one; and that, whilst this pub has gone on serving fine food according to the fixed hygiene laws of Tring, from so simple a beginning endless foods most beautiful and most wonderful have been, and are being, devoured.” And Emma, cake then firmly in hand, would have said something like, “My dear Charles, I shall try this enticing dessert, and I am glad to see you so enthused about something other than barnacles. Write a letter to Huxley or Lyell about that cake later. You need to focus on concocting an ending to that big species book of yours, not cakes. It’s been 20 bloody years, dude; cake can wait. End the book on a high note.” And so it must have happened.

Working at a museum collection is like having an extra home/office for a day or more. You get familiar with the environment while working there, and start to settle in and enjoy the local environs while taking work breaks. Or I do, anyway. So this post is also partly about how cake and other provisions are an important part, or even a perk, of life as a visiting museum researcher. Put in some good solid work, then it’s cake time, but where are the cakes? You explore, and you discover them– opening the door of an unfamiliar shop or pub near a museum can be like opening a museum cabinet to discover the goodness inside. Just don’t get them mixed up. Museum specimens: for research; subjects for science. Cakes: for eating; fuel for scientists. Got it?

But I digest digress. This post is not about my lunch. Not so much, anyway, although I did enjoy the cake quite a bit. Back to the chickens. Here, try some!

Darwins-chickens (1)Darwins-chickens (6)

Darwins-chickens (5) Darwins-chickens (4)

Above: Views of Darwin’s chickens laid out at the NHM-Tring.  (all photos in this post can be clucked to emchicken them)

The chickens, much like the pub lunch, did not disappoint in the least. Here I had before me Darwin’s own personal specimens, which I envisioned him dissecting and defleshing himself, studying them in deep introspection, then handing them over to the museum for curation once his lengthy researches were complete (all the ones I studied dated back to around 1863-1868, so they were curated shortly after The Origin was published (1859)). Perhaps the museum gave him some fine sponge-cake in return. There was at least one male and female adult of each of numerous breeds, many of them still bearing the dried flesh of centuries past. This was great for me, as the patella often gets removed and clucked chucked in the bin with its tendon when museum specimens of birds are prepared (much as elephant “sixth toe” sesamoids are). All of the specimens had their honking huge patellae on display, so that’s what a lot of my photos feature. I do so lament that I did not take a photo of the cake. Did I tell you about that cake? Oh… Check out these examples of Darwin’s chickens:

XXXX breed in right side view, with the patella indicated by a red arrow. It is still attached to the tibiotarsus by the patellar tendon (often misnamed the patellar "ligament", but it is just a continuation of the proximal tendon).

African rooster (wild variety? Darwin’s label was not clear) in right side view, with the patella indicated by a red arrow. That patella is still attached to the tibiotarsus by the patellar tendon (often misnamed the patellar “ligament”, but it is just a continuation of the proximal tendon).

Darwin's handwritten label and the well-endowed patella of the Spanish Cock. What? Oh, you. Stop it.

Darwin’s handwritten label and the well-endowed patella of the Spanish Cock. What? Oh, you. Stop it. That has nothing to do with cake, and only cake-related humour is allowed in this post.

Some other fascinating features exhibited by Darwin’s chickens, which he doubtless mulled over while nibbling on fine cakes, included the following:

The hindlimb of a Polish Silver Laced breed, nicely showing the ossified tendons (red arrow) along the tarsometatarsus. Why these tendons turn into bone is one of the great unsolved mysteries of bone biology/mechanics and avian evolution. Check out the famed feather crest here.

The hindlimb of a Polish Silver Laced breed, nicely showing the ossified tendons (red arrow) along the tarsometatarsus. Why these tendons turn into bone is one of the great unsolved mysteries of bone biology/mechanics and avian evolution.

Check out the famed feather crest of the Silver (Laced) Polish here; it gets so extreme in males that they have a hard time seeing, and can get beaten up by other cockerels when kept in mixed breed flocks.

Here on this blog, and of course on the companion blog “Towards the Chicken of the Future,” domestic chickens and wild junglefowl have often come up, most recently with the Dorking Chicken (another of Darwin’s own specimens that I studied) in the “Mystery Museum Specimen” poetry round of late. Dorkings are HUGE chickens; easily twice the weight of even a broiler chicken, up to 4-5kg. The Dorking-characteristic polydactyly featured in that post is also observed at a relatively high incidence in Silkie and Sultan breeds, I’ve learned. Like this one! (I was so patella-focused, or cake-somnolescent, that I missed it while studying at the museum and only noticed it now while browsing through my photos, bereft of cake)

Nice leg of a Sultan hen. There is an extra toe here as in the Dorking chicken; a duplicate hallux (first toe). This is not, as it might at first seem, a pathological condition as in modern "twisted toe"-suffering domestic chickens.

Nice leg of a Sultan hen. There is an extra toe here as in the Dorking chicken; a duplicate hallux (first toe). This is not, as it might at first seem, a pathological condition as in modern “twisted toe”-suffering domestic chickens.

Malays are another giant breed like the Dorking, but with longer and more muscular legs and longer necks, looking much more like a classic, badass wild junglefowl than a fancy, pampered chicken. But here, undressed to the bare bones, it just looks like a skinny chicken leg, albeit perhaps a bit svelte compared to the Dorking or Sultan.

Hindlimb of a Malay breed of chicken, which Wikipedia nicely tells the story of its misnomer (it may originate from Pakistan, not Malaysia!). Can you find the nice patella? Check out Darwin's lovely label, too.

Hindlimb of a Malay breed of chicken, which Wikipedia nicely tells the story of its misnomer (it may originate from Pakistan, not Malaysia!). Can you find the nice patella? Check out Darwin’s lovely label, too.

You may have come across wild-eyed news stories 5 years ago about “OMG Darwin was sooooooo wrong about chickens!”, referring to his writings on the origin of domestic chickens from Red junglefowl. As Greg Laden adeptly wrote, Darwin (say it with me) didn’t really get it very wrong after all. He did quite well, in fact. Some media outlets did get it more wrong, probably inspired by this press release. Oh well; the science they were reporting about definitely was interesting- modern chickens seem to have some of their yellow skin pigmentation-related genes from Grey junglefowl, although they are still largely descendants of Red junglefowl.

Here, have a JUMBLE-fowl, or rather a junglefowl cockerel, with another Darwin label:

Darwin's example of a wild-type chicken; a Red Junglefowl. As he suspected, these Asian birds were the ancestors of domestic chickens, but today evidence suggests that domestication occurred multiple times in Asia and with different wild varieties of junglefowl bred/mixed in different regions.

Darwin’s example of a wild-type chicken; a Red junglefowl. As he suspected, these Asian birds were the ancestors of domestic chickens, but today evidence indicates that domestication may have occurred multiple times in Asia and with different wild varieties of junglefowl bred/mixed in different regions.

Some breeds aren’t so funky inside, of course, but just have cool feather patterns on the outside, like the “pencilling” (dark streaks on white feathers) evident in pencil breeds; also called triple-laced. Like this fine chap below once would have had, before Darwin tore off his feathers and reduced him to a research-friendly naked skeleton:

A Golden Pencil Hamburgh breed of chicken (cockerel), whose skeleton features the leg and a fine articulated patella.

A Golden Pencil(led) Hamburg breed of chicken (cockerel), whose skeleton features the leg and a fine articulated patella.

Also known as the Holland Fowl, several European countries including the UK claim the Hamsburg as an original breed from their respective realm, and no surprise they do- it’s a lovely spangled chicken. Then, later in the 1800′s the Americans got involved in breeding them, too, and it’s all a big mess. They should get together, have some delectable cakes, and just sort it out.

Scaly, still-greasy foot and hindlimb of what Darwin labelled as the male of a "Game" breed.

Scaly, still-greasy foot and hindlimb of what Darwin labelled as the male of a “Game” breed.

We thus close with another leg of another chicken. Darwin was a bit naughty here, or else terminology of breeds has changed a lot since the 1850′s (very possible), as he just labelled this as a “Game” cockerel. Now, Gamefowl is a big category of breeds. I’m guessing this one was either (1) a Cornish/Indian Game variety or (2) an Old or Modern English Game Fowl. Maybe a person who knows their chicken breeding far better than me (that’s not hard!) will opine differently. The latter varieties were popular in Darwin’s time — the (Muffed) Old English version was mated with other breeds (Malay?) to produce the Modern English form as cockfighting “sports” became banned in 1849 and breeder attentions shifted to the polar opposite of producing showy, fancy birds instead. And thus the bufante, feathered-hair-adorned 1980s pop-rock group was created, to sing about mating or moulting or melting with people or something terribly disgusting and probably having nothing at all to do with chickens,  cake, or cockfighting, or other more seemly pursuits.

So, we have come to the end of my photos of Darwin’s chicken leg bones and such. If you’ve learned something here about chicken breeds, patellae, cake, or Darwin, that’s simply frabjous. Enough of those poncey pigeons, already! I’m crying fo… no, I won’t use that pun. Nevermind. Not even remotely cake-related. Let’s give Darwin’s chickens their just desserts, is the point– and a much better pun, too. Darwin’s chickens are an important part of Darwiniana, and an interesting evolutionary study in and of themselves. I’ve certainly become impressed during my researching for this blog post by the diverse, fascinating biology of chicken breeds. My copy of the “Complete Encyclopedia of Chickens” will be getting some more thorough reading shortly.

Today, however, I am off to return to the NHM-Tring and peruse their other, non-chickeny Galliformes and Anseriformes, with a detour to the mythical hoatzin. But… but… there may be a cake detour involved, too. I shall report back in due course. Off I go!

No, hopefully not that cake.

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Models of a basal dinosaur and bird, showing methods and key differences in body shape.

Our 3D computer models of a basal dinosaur and bird, showing methods and key differences in body shape. The numbers at the bottom are museum specimen numbers.

At about the moment I’m posting this, our Nature paper (our more formal page here, and the actual article here) embargo is ending, drawing a 14+ year gestation to a close. The paper is about how dinosaur 3D body shape changed during their evolution, and how that relates to changes in hindlimb posture from early dinosaurs/archosaurs to birds; “morpho-functional evolution” sums up the topic. We used the 3D whole-body computational modelling that I, Allen and Bates (among others) have developed to estimate evolutionary changes in body dimensions, rather than focusing on single specimens or (as in our last study) tyrannosaur ontogeny. We’ve strongly supported the notion (dating back to Gatesy’s seminal 1990 Paleobiology paper) that the centre of mass of dinosaurs shifted forwards during their evolution, and that this shift gradually led to the more crouched (flexed) hind leg posture that characterizes living birds. Here is a movie from our paper showing how we did the modelling:

And here is a summary of our 17 computer models of archosaur bodies, shown as one walks along the tips of the phylogeny shown in the video (the models are not considered to be ancestral to one another; we used a common computer algorithm called squared-change parsimony to estimate ancestral state changes of body dimensions between the 16 numbered nodes of the tree):

But we’ve done much more than just put numbers on conventional wisdom.

We’ve shown, to our own surprise, that the shift of the centre of mass was largely driven by evolutionary enlargements of the forelimbs (and the head and neck, and hindlimbs, to a less strong degree), not the tail as everyone including ourselves has assumed for almost 25 years. And the timing of this shift occurred inside the theropod dinosaur group that is called Maniraptora (or Maniraptoriformes, a slightly larger group), so the change began in animals that were not flying, but not long before flight evolved (depending on whom you ask, what taxonomy they favour and what evidence one accepts, either the smaller clade Eumaniraptora/Paraves or the bird clade Aves/Avialae).

Now, if you don’t like the cliche “rewriting the textbooks”, do have a look through texts on dinosaur/early avian palaeobiology and you probably will find a discussion of how the tail shortened, the centre of mass moved forwards as a consequence, the caudofemoral musculature diminished, and theropod dinosaurs (including birds) became more crouched as a result. We did that to confirm for ourselves that it’s a pretty well-accepted idea. Our study supports a large proportion of that idea’s reasoning, but modifies the emphasis to be on the forelimbs more than the tail for centre of mass effects, so the story gets more complex. The inference about caudofemoral muscles still seems quite sound, however, as is the general trend of increased limb crouching, but out paper approximates the timing of those changes.

Figure 3 from our paper, showing how the centre of mass moved forwards (up the y-axis) as one moves toward living birds (node 16); the funny dip at the end is an anomaly we discuss in the paper.

Figure 3 from our paper, showing how the centre of mass moved forwards (up the y-axis) as one moves toward living birds (node 16); the funny dip at the end is an anomaly we discuss in the paper.

A final implication of our study is that, because the forelimbs’ size influenced the centre of mass position, and thus influenced the ways the hindlimbs functioned, the forelimbs and hindlimbs are more coupled (via their effects on the centre of mass) than anyone has typically considered. Thus bipedalism and flight in theropods still have some functional coupling– although this is a matter of degree and not black/white, so by no means should we do away with helpful concepts like locomotor modules.

And in addition to doing science that we feel is good, we’ve gone the extra mile and presented all our data (yes, 17 dinosaurs’ worth of 3D whole body graphics!) and the critical software tools needed to replicate our analysis, in the Dryad database (link now working!), which should have now gone live with the paper! It was my first time using that database and it was incredibly easy (about 1 hour of work once we had all the final analysis’s files properly organized)– I strongly recommend others to try it out.

That’s my usual general summary of the paper, but that’s not what this blog article is about. I’ll provide my usual set of links to media coverage of the paper below, too. But the focus here is on the story behind the paper, to put a more personal spin on what it means to me (and my coauthors too). I’ll take a historical approach to explain how the paper evolved.


This paper’s story, with bits from the story of my life:

Embarassing picture of me before I became a scientist. Hardee's fast food restaurant cashier, my first "real job."

Embarassing picture of me before I became a scientist. Hardee’s fast food restaurant cashier, my first “real job”, from ~1999- no, wait, more like 1986. The 1980s-style feathered (and non-receding) hair gives it away!

Rewind to 1995. I started my PhD at Berkeley. I planned to use biomechanical methods and evidence to reconstruct how Tyrannosaurus rex moved, and started by synthesizing evidence on the anatomy and evolution of the hindlimb musculature in the whole archosaur group, with a focus on the lineage leading to Tyrannosaurus and to living birds. As my PhD project evolved, I became more interested and experienced in using 3D computational tools in biomechanics, which was my ultimate aim for T. rex.

In 1999, Don Henderson published his mathematical slicing approach to compute 3D body dimensions in extinct animals, which was a huge leap for the field forward beyond statistical estimates or physical toy models, because it represented dinosaurs-as-dinosaurs (not extrapolated reptiles/mammals/whatever) and gave you much more information than just body mass, with a lot of potential to do sensitivity analysis.

I struggled to upgrade my computer skills over the intervening years. I was developing the idea to reconstruct not only the biomechanics of T. rex, but also the evolutionary changes of biomechanics along the whole archosaur lineage to birds– because with a series of models of different species and a working phylogeny, you could do that. To me this was far more interesting than the morphology or function of any one taxon, BUT required you to be able to assess the latter. So Tyrannosaurus became a “case study” for me in how to reconstruct form and function in extinct animals, because it was interesting in its own right (mainly because of its giant size and bipedalism). (Much later, in 2007, I finally finished a collaboration to develop our own software package to do this 3D modelling, with Victor Ng-Thow-Hing and F. Clay Anderson at Honda and Stanford)

Me and a Mystery Scientist (then an undergrad; now a successful palaeontologist), measuring up a successful Cretaceous hypercarnivore at the UCMP; from my PhD days at Berkeley, ~2000 or so.

Me and a Mystery Scientist (then an undergrad; now a very successful palaeontologist!), measuring up a successful Cretaceous hypercarnivore at the UCMP; from my PhD days at Berkeley, ~2000 or so.

In all this research, I was inspired by not only my thesis committee and others at Berkeley, but also to a HUGE degree by Steve Gatesy, a very influential mentor and role model at Brown University. I owe a lot to him, and in a sense this paper is an homage to his trailblazing research; particularly his 1990 Paleobiology paper.

In 2001, I got the NSF bioinformatics postdoc I badly wanted, to go to the Neuromuscular Biomechanics lab at Stanford and learn the very latest 3D computational methods in biomechanics from Prof. Scott Delp’s team. This was a pivotal moment in my career; I became partly-an-engineer from that experience, and published some papers that I still look back fondly upon. Those papers, and many since (focused on validating and testing the accuracy/reliability of computer models of dinosaurs), set the stage for the present paper, which is one of the ones I’ve dreamed to do since the 1990s. So you may understand my excitement here…

Stanford's Neuromuscular Biomechanics Lab, just before I left in 2003.

Stanford’s Neuromuscular Biomechanics Lab, just before I left in 2003.

But the new paper is a team effort, and was driven by a very talented and fun then-PhD-student, now postdoc, Dr Vivian Allen. Viv’s PhD (2005-2009ish) was essentially intended to do all the things in biomechanics/evolution that I had run out of time/expertise to do in my PhD and postdoc, in regards to the evolution of dinosaur (especially theropod) locomotor biomechanics. And as I’d hoped, Viv put his own unique spin on the project, proving himself far better than me at writing software code and working with 3D graphics and biomechanical models. He’s now everything that I had hoped I’d become by the end of my postdoc, but didn’t really achieve, and more than that, too. So huge credit goes to Viv for this paper; it would never have happened without him.

We also got Karl Bates, another proven biomechanics/modelling expert, to contribute diverse ideas and data. Furthermore, Zhiheng Li (now at UT-Austin doing a PhD with Dr Julia Clarke) brought some awesome fossil birds (Pengornis and Yixianornis) from the IVPP in Beijing in order to microCT scan them in Londo. Zhiheng thus earned coauthorship on the paper — and I give big thanks to the Royal Society for funding this as an International Joint Project, with Dr Zhonghe Zhou at the IVPP.

That’s the team and the background, and I’ve already given you the punchlines for the paper; these are the primitive and the derived states of the paper. The rest of this post is about what happened behind the scenes. No huge drama or anything, but hard, cautious work and perseverance.

Me shortly after I moved to the RVC; video still frame from a dinosaur exhibit I was featured in. Embarassingly goofy pic, but I like the blurb at the bottom. It's all about the evolutionary polarity, baby!

Me shortly after I moved to the RVC; video still frame from a dinosaur exhibit (c. 2004) I was featured in. Embarassingly goofy pic, but I like the blurb at the bottom. It’s all about the evolutionary polarity, baby!

The paper of course got started during Viv’s PhD thesis; it was one of his chapters. However, back then it was just a focus on how the centre of mass changed, and the results for those simple patterns weren’t very different from those we present in the paper. We did spot, as our Nature supplementary information notes,  a strange trend in early theropods (like Dilophosaurus; to a lesser degree Coelophysis too) related to some unusual traits (e.g. a long torso) and suggested that there was a forward shift of centre of mass in these animals, but that wasn’t strongly upheld as we began to write the Nature paper.

On the urging of the PhD exam committee (and later the paper reviewers, too), Viv looked at the contributions of segment (i.e. head, neck, trunk, limbs, tail) mass and centre of mass to the overall whole body centre of mass. And I’m glad he did, since that uncovered the trend we did not expect to find: that the forelimb masses were far more important for moving the centre of mass forwards than the mass (or centre of mass) of the tail was– in other words, the statistical correlation of forelimb mass and centre of mass was strong, whereas changes of tail size didn’t correlate with the centre of mass nearly as much. We scrutinized those results quite carefully, even finding a very annoying bug in the 3D graphics files that required a major re-analysis during peer review (delaying the paper by ~6 months).

The paper was submitted to Nature first, passing a presubmission inquiry to check if the editor felt it fit the journal well enough. We had 3 anonymous peer reviewers; 1 gave extensive, detailed comments in the 3 rounds of review and was very fair and constructive, 1 gave helpful comments on writing style and other aspects of presentation as well as elements of the science, and 1 wasn’t that impressed by the paper’s novelty but wanted lots more species added, to investigate changes within different lineages of maniraptorans (e.g. therizinosaurs, oviraptorosaurs). That third reviewer only reviewed the paper for the first round (AFAIK), so I guess we won them over or else the editor overruled their concerns. We argued that 17 taxa were probably good enough to get the general evolutionary trends that we were after, and that number was ~16 more species than any prior studies had really done.

Above: CT scan reconstruction of the early extinct bird Yixianornis in slab conformation, and then Below: 3D skeletal reconstruction by Julia Molnar, missing just the final head (I find this very funny; Daffy Duck-esque) which we scaled to the fossil’s dimensions from the better data in our Archaeopteryx images. Yixianornis reconstruction There is also the concern, which the reviewers didn’t focus on but I could see other colleagues worrying about, that some of the specimens we used were either composites, sculpted, or otherwise not based on 100% complete, perfectly intact specimens. The latter are hard to come by for a diversity of extinct animals, especially in the maniraptoran/early bird group. We discussed some of these problems in our 3D Tyrannosaurus paper. The early dinosauromorph Marasuchus that we used was a cast/sculpted NHMUK specimen based on original material, as was our Coelophysis, Microraptor and Archaeopteryx; and our Carnegie ??Caenagnathus?? specimen was based more on measurements from 1 specimen than from direct scans, and there were a few other issues with our other specimens, all detailed in our paper’s Supplementary Information.

But our intuition, based on a lot of time spent with these models and the analysis of their data, is that these anatomical imperfections matter far, far less than the statistical methods that we employed– because we add a lot of flesh (like real animals have!) outside of the skeleton in our method, the precise morphology of the skeleton doesn’t matter much. It’s not like you need the kind of quality of anatomical detail that you need to do systematic analyses or osteological descriptive papers. The broad dimensions can matter, but those tend to be covered by the (overly, we suspect) broad error bars that our study had (see graph above). Hence while anyone could quibble ad infinitum about the accuracy of our skeletal data, I doubt it’s that bad– and it’s still a huge leap beyond previous studies, which did not present quantitative data, did not do comparative studies of multiple species, or did not construct models based on actual 3D skeletons as opposed to artists’ 2D shrinkwrapped reconstructions (the “Greg Paul method”). We also did directly measure the bodies of two extant archosaurs in our paper: a freshwater crocodile and a junglefowl (CT scan of the latter is reconstructed below in 3D).

One thing we still need to do, in future studies, is to look more carefully inside of the bird clade (Aves/Avialae) to see what’s going on there, especially as one moves closer to the crown group (modern birds). We represented modern birds with simply 1 bird: the “wild-type chicken” Red junglefowl, which isn’t drastically different in body shape from other basal modern birds such as a tinamou. Our paper was not about how diversity of body shape and centre of mass evolved within modern birds. But inspecting trends within Palaeognathae would be super interesting, because a lot of locomotor, size and body shape changes evolved therein; ostriches are probably a very, very poor proxy for the size and shape of the most recent common ancestor of all extant birds, for example, even though they seem to be fairly basal within that whole lineage. And, naturally, our study opens up opportunities for anyone to add feathers to our models and investigate aerodynamics, or to apply our methods to other dinosaur/vertebrate/metazoan groups. If the funding gods are kind to us, later this year we will be looking more closely, in particular, at the base of Archosauria and what was happening to locomotor mechanics in Triassic archosaurs…

Clickum to embiggum:

Australian freshwater crocodile, Crocodylus johnstoni; we CT scanned it in 3 pieces.

Australian freshwater crocodile, Crocodylus johnstoni; we CT scanned it in 3 pieces while visiting the Witmer lab in Ohio.

A Red junglefowl cockerel, spotted in Lampang, Thailand during one of my elephant gait research excursions there. Svelte, muscular and fast as hell.

A Red junglefowl cockerel, spotted in Lampang, Thailand during one of my elephant gait research excursions there. Svelte, muscular and fast as hell. This photo is here to remind me to TAKE BLOODY PICTURES OF MY ACTUAL RESEARCH SPECIMENS SO I CAN SHOW THEM!

I’d bore you with the statistical intricacies of the paper, but that’s not very fun and it’s not the style of this blog, which is not called “What’s in John’s Software Code?”. Viv really worked his butt off to get the stats right, and we did many rounds of revisions and checking together, in addition to consultations with statistics experts. So I feel we did a good job. See the paper if that kind of thing floats your boat. Someone could find a flaw or alternative method, and if that changed our major conclusions that would be a bummer– but that’s science. We took the plunge and put all of our data online, as noted above, so anyone can do that, and that optimizes the reproducibility of science.

What I hope people do, in particular, is to use the 3D graphics of our paper’s 17 specimen-based archosaur bodies for other things– new and original research, video games, animations, whatever. It has been very satisfying to finally, from fairly early in the paper-writing process onwards, present all of the complex data in an analysis like this so someone else can use it. My past modelling papers have not done this, but I aim to backtrack and bring them up to snuff like this. We couldn’t publish open access in Nature, but we achieved reasonably open data at least, and to me that’s as important. I am really excited at a personal level, and intrigued from a professional standpoint, to see how our data and tools get used. We’ll be posting refinements of our (Matlab software-based) tools, which we’re still finding ways to enhance, as we proceed with future research.

Velociraptor-model-min Dilophosaurus-model-min00

Above: Two of the 17 archosaur 3D models (the skinny “mininal” models; shrinkwrapped for your protection) that you can download and examine and do stuff with! Dilophosaurus on the left; Velociraptor on the right. Maybe you can use these to make a Jurassic Park 4 film that is better, or at least more scientifically accurate, than Hollywood’s version! ;-) Just download free software like Meshlab, drop the OBJ files in and go!

Now, to bring the story full circle, the paper is out at last! A 4 year journey from Viv’s PhD thesis to the journal, and for me a ~14 year journey from my mind’s eye to realization. Phew! The real fun begins now, as we see how the paper is received! I hope you like it, and if you work in this area I hope you like the big dataset that comes with it, too. Perhaps more than any other paper I’ve written, because of the long voyage this paper has taken, it has a special place in my heart. I’m proud of it and the work our team did together to produce it. Now it is also yours. And all 3200ish words of this lengthy blog post are, as well!

Last but not least, enjoy the wonderful digital painting that Luis Rey did for this paper (another of my team’s many failed attempts to get on the cover of a journal!); he has now blogged about it, too!

Dinosaur posture and body shape evolving up the evolutionary tree, with example taxa depicted.

Dinosaur posture and body shape evolving up the evolutionary tree, with example taxa depicted. By Luis Rey.


News stories about this paper will be added below as they come out, featuring our favourites:

1) NERC’s Planet Earth, by Harriet Jarlett: “Dinosaur body shape changed the way birds stand

2) Ed Yong on Phenomena: “Crouching  bird, hidden dinosaur

3) Charles Choi on Live Science: “Crouching bird, hidden evolutionary purpose?

4) Brian Handwerk on Nat Geo Daily News: “Birds’ “Crouching” Gait Born in Dinosaur Ancestors

5) Jennifer Viegas on Discovery News: “Heavier dino arms led evolution to birds

6) Puneet Kollipara on Science News: “Birds may have had to crouch before they could fly

And some superb videos- we’re really happy with these:

1) Nature’s “Crouching Turkey, Hidden Dragon

2) Reuters TV’s “3D study shows forelimb enlargement key to evolution of dinosaurs into birds

Synopsis: Decent coverage, but negligible coverage in the general press; just science-specialist media, more or less. I think the story was judged to be too complex/esoteric for the general public. You’d think dinosaurs, evolution, computers plus physics would be an “easy sell” but it was not, and I don’t think we made any big errors “selling” it. Interesting– I continue to learn more about how unpredictable the media can be.

Regardless, the paper has had a great response from scientist colleagues/science afficionados, which was the target audience anyway. I’m very pleased with it, too– it’s one of my team’s best papers in my ~18 year career.

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frontcover

The Unfeathered Bird book by Katrina van Grouw proclaims immediately in its Introduction that it “is not an anatomy of birds.”  True– it is far more than that, and it would be a shame if it had just been a dry, technical avian osteology reference book. It is a unique blend of art and science- particularly avian anatomy, evolution, taxonomy, natural history and more. The Unfeathered Bird is written for a general audience; birders/twitchers or just natural history buffs would be ideal targets of its unfettered passion for all things avian. A 12-year-old who is very keen on animals could enjoy it, and it may ignite the flames of ornithological excitement in many young or older readers. I am glad it was not called “The Naked Bird” as that would have caused some serious misconceptions (badum-tish!). The book is dripping with illustrations (at least one every two pages, often more). Almost all of the illustrations (except some paintings in the style of the cover) are in the same brownish sketch style that, like much of the book, evokes a bygone era of dark wooden cabinets and shadowed halls packed with skeletons, with nary an interactive graphics display, animatronic dinosaur or hyperdetailed cladogram in sight. It feels like an homage to the Victorian naturalists’ joy for anatomical detail conveyed through painstakingly detailed woodcuts. And while many still think of feathers as “the defining feature of birds,” enough about feathers already. Seriously. This is a book is about what lies beneath, and how all that non-fluffy stuff is important for birds’ lives, too.

(image-intense post; all can be clicked to embiggritate)

Katrina with peacock feather headdress? (back cover pic and rear view of same skeleton)

Katrina with peacock feather headdress? (back cover pic and rear view of same skeleton)

Katrina with front cover framed pic and the peacock skeleton that went with it.

Katrina with front cover framed pic and the peacock skeleton that went with it.

The Introduction continues to explain that the book is truly about how the external anatomy of birds is linked to the bony anatomy, which might remind astute readers of modern approaches like the extant phylogenetic bracket. The rest of the book uses both skeletal and unfeathered, quasi-myological illustrations to get this point across vividly. The explanatory text is written at a basic enough level for the average reader and is just the right length, with interesting anecdotes and natural history facts that even the expert reader will find interesting or even inspirational (e.g. possibly a goldmine for research ideas). First there is a 26 page “Basic” section with an introduction to avian osteology, with bountiful sketches to illustrate key organs and text explaining how it all fits together in the fully accoutered bird. The decision to use classical Linnean taxonomy (defunct or re-arranged taxa from the Systema Naturae like Accipitres, Picae, Anseres, Grallae, Gallinae and Passeres; which are the six “Specific” chapters in the second section of the book) was a good one- it enhances the classical feel of the tome and gives the author a great opportunity to discuss convergent evolution and how that misled past ornithologists.

But for me, the book is most pleasurable for the visualizations and the passion for all things birdy that weaves through them and the accompanying text. The removal of feathers, or even all soft tissues, from bird bodies (posed in naturalistic behaviours) that van Grouw renders in her illustrations shows birds in a new light, emphasizing the strangeness and diversity that lie beneath. The author begins the book with a touching Acknowledgments section in which her husband Hein van Grouw, curator of birds at the Natural History Museum’s Tring collection, features very prominently, making it clear that the book was a team operation and comes from the heart after a 25-year journey. This gives the book a special warmth that is preserved throughout the remainder- although the illustrations are of flayed bodies or boiled / beetle-macerated skeletons, the tone is nothing less than an earnest love for birds of all kinds, and a zest for portraying those feelings to the reader in sketches and prose. It is a joyous celebration, not a somber litany, of the wonder of birds that can be gleaned from dead bodies. There is so much powerful, awesome imagery stuffed into those pages that it is hard to summarize. I’ll let five of my favourite images from the book (more are in her gallery and her book’s Facebook page; but even these are just the tip of the icebird) help get this across (used with permission of the author):

Naked kiwi in action.

Naked kiwi in action.

The unscaled bird: guineafowl feet.

The unscaled bird: guineafowl feet.

Deplumed sparrowhawk with dove trophy, exalting in its triumph.

Deplumed sparrowhawk with dove trophy, exalting in its triumph.

Budgerigar has made a friend? Or came to grips with its own mortality?

Budgerigar has made a friend? Or came to grips with its own mortality?

Trumpet Manucode WTF anatomy! Spiraling tracheal coil made me gasp in awe when I saw this image in the book.

Trumpet Manucode’s WTF anatomy! Spiraling tracheal coil made me gasp in awe when I saw this image in the book.

Now I’ll depart from this post just being a book review. I went to the Tring collection to do some research, and arranged my trip so I’d also get to see the debut of a Tring special exhibit featuring The Unfeathered Bird, and also to meet Katrina as well as Hein van Grouw. The placement of the exhibit at Tring is apropos, because Katrina was a curator at the museum until a few years ago and Hein still is. But the inspiration for the work and the specimens used (with a few exceptions, including from other museums) are Katrina’s. She (with Hein’s help) procured bodies of birds to dissect, macerate and sketch for the book over its 25 year fledging period, noting in the Acknowledgments that “no birds were harmed” to do this– do read those acknowledgments, as there are some amusing tales there of how she obtained some specimens.

I was fortunate to be able to take some photos of the exhibit while they set it up, and grabbed some candid images of Katrina and colleagues during that process. The following images show off the exhibit, which is all in one clean, bright, simply adorned room in the Tring that lets Katrina’s framed sketches be the focus. Here are some examples:

Poster advert for the book in the Tring collections.

Poster advert for the book in the Tring collections.

Tring exhibit setup, with Katrina, husband Hein, and helper finishing it up.

Tring exhibit setup, with Katrina, husband Hein, and helper finishing it up.

Tring exhibit now ready.

Tring exhibit now ready.

Tring exhibit case.

Tring exhibit case.

Framed sketches at Tring exhibit.

Framed sketches at Tring exhibit.

Framed sketches at Tring exhibit.

More framed sketches at Tring exhibit.

The exhibit is fun for people who are already Unfeathered Bird fans, and a good way of drawing in new ones. The book is a precious thing that any fan of birds, especially scientists, really needs to have a hard copy of. While it claims not to be an anatomy text, its illustrations provide ample opportunities to use it for that purpose. But really the point of owning all 287-plus pages is to bask in the warmth of true, pure appreciation for classic ornithology, which I found infectious. It is a book by and for bird lovers, but also for those that find the interface of art and science to be fascinating.

I confess I used to hate birds. I found them annoying and boring; all that flitting and twitting and pretentious feathers. “Get over yourselves, already, and calm down too!” was my reaction to them. When I started grad school, I had an open disdain for birds, even moreso than for mammals (OK, except cats). I was a “herp” fan through and through, for most of my life (childhood spent catching anoles in Florida, or stalking frogs in Ohio; during visits to my grandparents). What won me over was studying birds (and eventually mammals, too) as a young scientist, and learning how incredible they are– not just as endpoints in the story of theropod dinosaur evolution, as my thesis focused on, but as amazing animals with spectacular form-function relationships.  The Unfeathered Bird is saturated with that amazement, so we’re birds of an unfeather.

Framed sketch of dodo head at Tring exhibit.

Framed sketch of dodo head at Tring exhibit.

Entirely unfeathered Indian peafowl in matching views.

Entirely unfeathered Indian peafowl in matching views.

Painted Stork and Toco Toucan sketches.

Painted Stork and Great Hornbill sketches.

Red junglefowl, wild ancestor of domestic chickens (and the book ends with several such breeds illustrated),

Red junglefowl, wild ancestor of domestic chickens (and the book ends with several such breeds illustrated).

Katrina told me that she is already deep into writing the next book, whose subject I won’t spoil for you here but maybe we will be lucky enough to have her appear in the Comments and plug it? :) (Her website does say “It was Hein’s stroke of genius to include domestic birds and they’ve provided the inspiration for my next project.” so the cat is out of the bag and amongst the pigeons!) It is great to hear that the book has done quite well sales-wise and critically, such as ~#67 on the Amazon sales list at one point– I hope this paves the way for more such books not only from Katrina, but from others engaged in lateral thinking (and still others) on the boundaries of science-art.

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If you want to see a new/reinvigorated, exciting direction that palaeoart is headed, check out the All Yesterdays book by Conway, Kosemen and Naish. This review is fully cognizant that I’m late to the party of hailing this book as part of a palaeoart renaissance. I confess I haven’t read any of the many reviews of this book; I just know it is highly regarded and popular, from excitement on social media sites I frequent. So if my review covers ground others have too, so be it; it’s purely my own thoughts but I expect that mine fall in line with many others’. I’m reviewing the book on this blog because I love the interface between science and art (which is very important in anatomy), and because anatomy, and how one infers it when it is unknown, is the fundamental theme of the book.

You can buy All Yesterdays for around £18 (ASIDE: oddly, used copies (“May not include CD, access code, or DJ”– ???) are around £42 on the same site; perhaps those are artist-signed??? I have no idea!). It is a good deal at that price. While you’re at it, get “Dinosaur Art: The World’s Best Paleoart” by White et al. (including Conway) for a similar price. My review will return to some comparisons between these two books, released just a few months apart.

All-Yesterdays-coverworlds-greatest-paleoart

All Yesterdays is about not only how we reconstruct dinosaurs and other prehistoric animals, but also about thinking outside-the-box in the ways we reconstruct them and thereby bucking some recent clichés and tropes. Some of those outside-the-box ideas might seem ludicrous, and some probably are. But one of the main points of All Yesterdays is that there is plenty about extinct animals, and even living animals, that we don’t know, even though the field of paleoart has matured into greater scientific rigor than in the days of Knight, Zallinger and others (1920s-1950s). There is a focus on uncertainties about integument (e.g. feathering, spines, colour/patterning, body contours) and behaviour (e.g. avoiding stereotypes like perpetually aggressive predators and frightened prey animals– amen to that!). And the capstone of the book, which in some ways I loved the most, is turning the issue on its head and pretending that we only had skeletons of extant animals, then proceeding to reconstruct those animals (elephants, whales, horses and swans stand out prominently in this section; some of these are shown below). I wish more scientists in my general area would practice this; e.g. validation of a methodology used to reconstruct extinct animals in science.

The ‘speculative zoology’ of All Yesterdays deserves favourable comparison to one of my favourite science-art books, 1981′s After Man by Dougal Dixon. I fell so in love with that book as a 10-year-old that I wouldn’t let my parents return it to the library and I made them pay the hefty lost-book-fee (yes, I was a little bastard!). I still have it, too. (Sorry, Sequoya Branch Public Library of Madison, WI!) Likewise, the whimsy of the Rhinogrades is evoked by this work, and of course Tetrapod Zoology blog readers will be no strangers to it, either.

The book begins with a clear, succinct (7 page) summary of the history and science of reconstructing animals, with a focus on paleoart’s approach rather than science’s. I would have found it interesting (but space constraints presumably precluded) to feature more of the interface/parallels with scientists at the same time, such as the careful reconstructions of musculature in A.S. Romer’s masterful work in the 1920s (e.g. below), or later efforts by palaeontologists like Alick Walker and Walter Coombs. Many of these luminaries sought not to reconstruct animals for artistic purposes, but for almost purely scientific ones: to understand what skeletal anatomy meant in terms of broader biology (e.g. comparative anatomy) and phylogeny (e.g. origin of birds or archosaur evolution). The quality of their own artistic representations as well as scientific interpretations varied a lot. Indeed, sometimes the choice of model organisms (crocodile for Romer; lizard for Walker; birds in the post-1960′s) reveals much about the author’s preconceptions about phylogeny, marshalled towards a favoured hypothesis (e.g. a crocodile origin of birds for Walker; or an avian origin amongst dinosaurs for Bakker, Paul and others), rather than a circumspect assessment of all relevant evidence.

Romer1923-fig6

Figure 6 from Romer, 1923; very crocodylian T. rex right hindlimb muscles.

But eventually the “model organism” approach to reconstructing extinct animals gave way to the extant phylogenetic bracket; very popular today; which itself is an adaptation of the outgroup method for polarity assessment in phylogenetic systematics (cladistics). I am sure many modern paleoartists explicitly consider the “EPB” in their reconstructions, although this leaves many ambiguities (e.g. integument of crocodiles and birds being totally different!) that they must overcome, whereas scientists might just give up. This interface of art and science is part of what make palaeontology so enjoyable.

The EPB mindset has been a big step forward for evolutionary morphology and palaeontology, but still some of the greatest questions (e.g. what were the actual sizes, colour patterns, or behaviours of extinct animals? How did novelties arise and which novelties did dinosaurs have that extant relatives lack?) are left ambiguous by the EPB. This is because either the EPB itself is ambiguous (crocodiles or other taxa do one thing; birds do something altogether different), or because features leave no osteological correlates (e.g. muscle/tendon/ligament scars) on fossils that can be compared with the EPB.  This quandary leads to the fun side of this book– filling in the huge gaps left by both basic anatomical interpretation and the restrictions imposed by the EPB, and then playing with the frontiers of anatomical, behavioural and ecological reconstruction, using informed speculation.

The extant phylogenetic bracket for archosaurs.

The extant phylogenetic bracket for archosaurs.

In addition to the startling, bizarre “All Todays” reconstructions at the end of the book, the highlights for me were the camouflaged Majungasaurus and plesiosaur, the “feathered mountain” (below) of a therizinosaur (can anyone illustrate a plausible therizinosaur and make it normal and boring? I wager not!) and the neck-swinging elasmosaurs engaged in “honest signalling” of their fitness. Many of the illustrations riff on notions popular in the modern palaeo-zeitgeist (and subject of many conversations at conferences, or even publications), such as evidence for the spiny integument of some ornithischians, fat ornithopods, Microraptor of somewhat-known-colouration, and so on. But plenty of other images riff on a “well why not?” theme, challenging the viewer to consider that extinct animals could have many surprises left in store for us with future discoveries, or else plausible features that we’ll never know of but might seem laughable or unfashionable to illustrate now. Each image has text explaining the logic behind it- this is not just a montage of pictures. This is a thinking person’s book- you should buy it for rumination, to challenge your preconceptions, not to have a flashy coffee table book. It’s not eye candy — it’s more like brain jerky.

John Conway's mountain-of-feathers therizinosaurs: eerily beautiful.

John Conway‘s mountain-of-feathers therizinosaurs: eerily beautiful.

I think this is a bold, fun (re)new(ed) direction for palaeoart. There’s always a place for rigorous, conservatively evidence-based, by-comparison-almost-uncreative scientific illustration of extinct organisms. The World’s Best Paleoart presents loads of this, often in vividly colourful, photo-realistic, lavish, glossy detail, whereas the approach in All Yesterdays tends toward a more soft, matte, informal style including sketches or abstractions, toning down the serious and intense (even cluttered?) approach that can characterize modern palaeoart, including The World’s Best Paleoart.  Sometimes those reconstructing life of the past (scientists included!) may emphasize that detailed realism too much and lose some of the joyful playfulness that palaeoart can revel in, at its best, most inspirational or thought-provoking. The former style might be considered the more “safe” or technical practice; the latter more risky or unconstrained.

Memo Kosemen's "All Todays" swans, with tadpolefish, might haunt your nightmares.

C.M. Kosemen‘s “All Todays” swans, with tadpolefish, might haunt your nightmares.

I’m not casting negative judgement on either style; both are absolutely wonderful — and valuable. I love both books! I’m glad we’re in a new age where the fun is waltzing back into palaeoart, that’s all. All Yesterdays doesn’t just waltz, either. It pounces into your field of view, wiggles its rainbow-coloured, mandrill-esque ankylosaurid bottom at you with a cheeky grin, and proceeds to make you smirk, be bemused, and even gasp at its adventurousness in rapid succession as you turn its pages. At 100 pages it doesn’t overstay its welcome either– that kaleidoscopic thyreophoran rump cartwheels off into the sunset at an opportune moment.

You won't forget Memo Kosemen's "All Todays" elephant.

You won’t forget C.M. Kosemen‘s “All Todays” elephant.

If All Yesterdays makes someone uncomfortable with its swashbucklerish daring, they’re probably taking palaeontology way too seriously– and maybe missing not only some good fun, but also some potential truths. Dogma is a terrible thing, and All Yesterdays slaughters it with delightful relish. Bring on the next installment! If you have  All Yesterdays too, what’s your favourite part? Or if you don’t have it, I’d be happy to answer queries in the Comments.

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