Hi John, Congratulations for the blog!
I’m starting to work on the cranial musculature xenarthrans for some paleontological reconstructions, I wonder if you can recommend me some literature, contact, or source of images of dissections of actual armadillos.
greetings and thanks!
Thanks Manuel! Cranial musculature– I am pretty useless with that, to be honest. Casey Holliday, who fortuitously commented above, would be a great guy to ask about that. Armadillo dissections are something I’ve never come across in my own work or in the literature. I cannot think of any good references… sorry! You’ve stumped me! Xenarthran workers like Gaudin and colleagues would be a good start for some leads. Good luck!
Dillos don’t have much for muscles since they’re worm and bug eaters. Robert McAfee and Virginia Naples are the only people I know of that have worked on xenarthran muscles very much. Check out Robert’s most recent paper which includes muscle maps. I’m sure the lit cited in that paper will also help.
McAfee, RK. 2011 Feeding mechanics and dietary implications in the fossil sloth Neocnus (Mammalia: Xenarthra: Megalonychidae) from Haiti. Journal of Morphology, 272: 1204-1216.
First thought is skin from the underside or inside leg of a small croc. The scutes(?) are smaller and more numerous toward the top suggesting that more flexibility is required but protection is less critical, so that might be toward the midline or throat if belly skin.
There appears to be a flexion point at about 122mm so I’d guess that, if it’s a limb, that might be the crook of an “elbow” or back of a “knee”, otherwise where the limb meets the body.
As for where from, that’s easy – one of your freezers!
I shall keep you in nervewracking suspense no longer. As usual, we have some brilliant anatomists providing guesses, and they basically got the answer — mostly. It is crocodylian skin, from the hindlimb region around the knee (well done, Casey and Mark!).
BUT (cue pedantry!) the colour is a clue, although it is a very subtle clue at that, and cruelly blackhearted of me to be so subtle. This is not a crocodile but a Black Caiman, Melanosuchus niger; details here: http://crocodilian.com/cnhc/csp_mnig.htm
Somewhat endangered, rather little known, and very cool. We got one (>2m long) from a crocodile farm a few years ago and are still making the most of it thanks to our freezers.
The skin pattern is pretty close to what some dinosaur skin might have looked like (pebbly), albeit with less ossified tissue (scutes/armour) inside the skin in some species of dinosaurs. A billion nice examples are here: http://bit.ly/K1Uo0H
Hadrosaur (duckbill) skin is surprisingly common in the fossil record, so we do know a fair bit about that, and skin is known from quite a few other groups/species of dinosaurs… but I digress. Melanosuchus is awesome even without mentioning dinosaurs (Casey you can pay me my fee now for saying that, thanks very much). Hooray for M. niger, and hooray to today’s winners!