Worm Salad

Remarkable Reptile #6
December 7, 2008, 9:48 pm
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Okay, so fair warning — this post might get very long, since it’s all about the group that I am currently studying. And while I’m passionate to ramble about reptiles for thousand-word posts, when it comes to today’s subject, I’m good to ramble for, well, years probably. But, well, it wouldn’t be fair to list off a group of remarkable reptiles without including at least one crocodilian, and, of course, I picked the world’s most unique crocodile as my subject of study.

Crocodiles really are my favorite animals. People will tell you that they’re living fossils and that they have remained unchanged since the Jurassic, and while that’s sort-of true in that there’s a generalized ‘croc-shape’ that crocodiles tend to fall back on (and there certainly aren’t as many around as there used to be), it ignores the incredible fossil diversity of crocodiles through time. There are crocodiles that became terrestrial herbivores and crocodiles that took to an exclusively marine life and crocodiles that evolved mammal-life teeth and crocodiles that grew to forty feet. The ancestors of crocodiles were lithe, upright little predators with long legs who lived only on land, while the more typical crocodilian niche was occupied by their close-relatives: phytosaurs … which looked pretty much like a modern croc, except that they had their nostrils between their eyes.

See, look, I knew I would digress. The point is that crocodilian diversity is amazing, and even if they aren’t as diverse as they once were, their current diversity is amazing: from the five-foot long dwarf caiman of South America to Nile Crocodiles who live in marginal environments on the edge of the Sahara and their fossil diversity is beyond incredible. Their closest living relatives are birds, and, depending on who you ask, they might be very closely related to turtles. They differ from birds, though, in the morphology of their ankle — while bird ankle joints allow for a very limited front-back flexion, crocodile ankles, like yours, can rotate. This has some pretty interesting implications for their gait: basically it allows them to adopt a variety of different walking stances — they can walk upright like a mammal, sprawl like a lizard and can even gallop. The crocodilian biology database has a really fantastic page with videos of all the exciting forms of croc locomotion.

Nile Crocodile by padiyan on Flickr, used under CC license

Nile Crocodile, Crocodylus niloticus

Look, I’m digressing again. At this rate, we’ll never get to my remarkable crocodilian. Why don’t you just read on to find out what he is, before I get completely distracted. Continue reading