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:
My photographs are shown with kind permission from the Natural History Museum, London.
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:
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?):
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:
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?
The fleshy vs. skeletal foot of the Black Grouse is particularly interesting from an ichnology slant…the skeleton of a potential trackmaker does not necessarily reveal all the padding and fluffitude of a living, walking foot. At least it doesn’t for the ptarmigan feet I’m studying.
You should definitely talk about species concepts! Or am I the only one crazy enough to enjoy such a read?
Hehe I won’t bore you w/my views but Grrlscientist’s in the link provided in that section gives a pretty good overview.
Oh and yes, good point about ichnology!
These bird skulls with resonance chamber automatically make me thinking on the heads of hadrosaurs and the endless speculation about the form and function…
I’m a huge fan of the pelagornithids, although their exact phylogenetic affinities are debated. They would have been seriously impressive to see alive, especially the species with 5-6 m wingspan!
What’s your favourite neglected “primitive” bird group?
Are ropens birds?
Yes, in the clade with Big Bird and the Roc.
Brilliant post. Thoroughly enjoyed it, despite the lack of filthy swearing (not so much of a cake man myself; I prefer that most esteemed of gastropods, the whelk).
My own favourite is hardly neglected, but I love it anyway: Dromaius novaehollandiae, the emu. This is for no better reason than whilst at primary school we spent a week at the Cotswold Wildlife Park, and I took a shine to the emus there as they were obviously intelligent and always curious, coming over to see me when ever I visited their paddock. If ostriches are anything to go by, ratites get extra kudos for tasting so good too.
Thanks Stu! There’s plenty of opportunity for me to cuss in coming posts, so don’t lose faith! 🙂
I’ve neglected emus since we have them (now babies and adults!) around the RVC all the time. I love them, though; super interesting critters. Nice video of them here: http://www.nature.com/nature/videoarchive/turkey/index.html
Thanks for the link John, great emus! Lovin’ the models lots too.
Magpie Goose Anseranas – not a true goose but the next left turn after the screamers; I was bitten by them frequently at Sydney’s Taronga Zoo in my youth, they’re as common in the parks of Darwin (and it’s so cool there’s a city named after Mr D) as pigeons in Trafalgar Square, and the pied pattern is similar enough to some screamers, ducks and geese that it’s likely to be retained from the ancestral anseriform. I found some coracoids that Trevor Worthy identified as from a smallish ancestral anseranatid…
Also Dromornithids: giant flightless extinct anseriforms, not ratites. They left a shedload of bones at Riversleigh, and apparently were excellent crocodile chow.
I also like Scrub Turkeys: like seagulls to albatrosses, the (distantly related) mini-version of the Cassowary, similar in colour scheme and with analogous adaptations (viz. laterally compressed tail-fan) for threading through ‘scrub’, which is what we call rainforest in Oz. Unlike cassowaries, scrub turkeys roost communally in tall trees. Several of them broke my tent once by sitting on the ridgepole.
Thanks John! Good choices. I wish I had more Anseranas and even just a fragment of a dromornithid to study in the UK would be great!
Hi there. Long-time reader just venturing into the world of feedback. Regarding curassows, I have some experience with living animals of several different genera. Pauxi are the only ones with a substantial skeletal casque and I have heard the resonating chamber theory before but am not certain this is strictly accurate. Only male animals boom, but in this genus both sexes have comparable casques. The casque-less relatives from genus Crax also boom very well (again, only the guys). From what I kn vocalization is thought to be associated with dramatic and wonderful tracheal loops found in these (and many other) birds. Here’s a not-bad article on it: http://scienceblogs.com/tetrapodzoology/2009/04/29/elongate-avian-trachea/
Great points, thanks Rene! Ahh and as always, there is a great TetZoo post that is relevant- thanks for that too! 🙂
Whoops, got cut off mid-post. I have heard the casque resonation chamber theory for birds with casques, most notably the big Buceros hornbills. But I am not aware of any current research that supports the casques as resonating chambers idea. I’d love to see some though!
[…] 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 […]
[…] shelves area, it brings me to this trip and my purpose for it! I wanted to look at some “basal birds” for our ongoing patella (kneecap) evolution project, to check which species (or individuals, […]