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, 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.
Me getting familiar with external ostrich anatomy before we dive in. Large callouses on the breastbone, back of the pelvis, and “heel” region are visible. On the ostrich.
Ostrich hand showing the three digits: 1st (top), 2nd (middle), and 3rd (hidden behind skin, but still with a hint of a claw). What are they used for? Probably not a lot.
Outer view of the wing feathers attached to the hand; only the largest, thickest ones have been left unplucked. Note the puckered skin where feathers have been taken out of their follicles.
An odd cyst we found near the breastbone, embeded superficially onto the skin. We found another one like it skittering around freely inside the abdominal cavity. Just one of those wierd things. Sometimes during development, tissues don’t grow right, or grow to enclose foreign materials. forming a cyst.
View of the left side of the ostrich, skinned and partly gutted. Shoulder closest; then ribcage and left leg.
Left leg, skinned and revealing the massive thigh and calf muscles, which can constitute >20% of an ostrich’s weight per leg!
Guts! This was the great moment, from my perspective. I was dumbstruck by how gorgeous the intact purplish membranes of the large intestine’s mesenteries were. PhD student Sophie Regnault, in the background, probably saw so many animal guts during her vet degree that she seems less impressed. :-)
Ostriches are interesting in that their small intestine (bottom half of the image) leads into two pouches, called caeca (“normal” animals just have one caecum); upper middle of the image; and thence to the fairly simple large intestine (top of image), with no large rectal area to speak of.
Gizzard/ventriculus, upper stomach/proventriculus (upper left), and stomach contents: grass and stomach stones (gastroliths).
Looking into the thorax; with heart (was on far left side of photo) and liver removed to expose the air sacs around the lungs, and the lungs just past their translucent membrane.
Internal view of the ribcage, showing (left side; bright red colour) where the rigid avian lung is tightly adhered to the dorsal side of the thorax.
A curious region of the mid-thigh (caudal/posterior side), where two features are notable: (1) a ligamentous loop (called an ansa) from the femur that constrains the line of action of the big “hamstring” iliofibularis muscle (~mammalian biceps femoris), keeping the tendon (cut; sticking up vertically here) close to the knee; and (2) a series of very complex sheets of epithelium that partition a series of air sacs extending down the thigh; these also invade the femur near the hip. Yes, to a sense, an ostrich has bellows in its thighs that might aid its breathing as it runs. This aspect of ostrich anatomy is almost totally unstudied!
Skinned head, neck and thorax, exposing the trachea (windpipe) and esophagus (entry to gut; in my hand). There was an odd thickening in the esophagus here; we were not sure if this was injury or some sort of gland or muscular region. Anyway, this photo reminds me of scenes from John Carpenter’s “The Thing.” I felt disturbed by the skinned head and neck. Maybe that’s because I don’t normally study them much?
Bob Nicholls poses proudly with the head, neck and thorax, as dissections near their denouement. Thanks Bob!
I hope you appreciated the open-ostrich postmortem. We’ll bring you more from this dissection/project in future posts. Tomorrow, something different for Freezermas!