STL Science Center

STL Science Center

10 February 2016

How Are You, You?

Dromaeosaurs are a rather unique and novel form of theropod. We may have described what makes a theropod a dromaeosaur at some point in the past, or at least what makes a bird a theropod; this is not necessarily what makes a bird a dromaeosaur, but they are related ideas in the wider context of paleontology. Widely, dromaeosaurs are feathered, bipedal, saurischian dinosaurs with many avian or paravian characteristics that still possess many diagnostically theropod characteristics as well. What does that really mean? It means that Dakotaraptor and other dromaeosaurs have theropod features like two temporal fenestrae, sharped curved and serrated teeth (these ziphodont teeth are typical, but not necessarily required), and thin walled hollow bones. The arrangement of toes and fingers is also important in theropod dinosaurs. In dromaeosaurs the second claw of the foot is the well-known sickle shaped foot claw. This claw in Dakotaraptor equals approximately 29% the length of the femur. That means that the sickle claw of Dakotaraptor was nearly 16.2 cm long in the holotype individual (femur length is 55.8 cm). Feathers, furculae, and pneumatized bone are all avian characteristics that are shared by Dakotaraptor and other dromaeosaurs and birds. Dakotaraptor shares more traits with its smaller cousins than did the equally large dromaeosaur Utahraptor, most notably its lighter built and more agile frame, lending itself to inferences of pursuit predation as opposed to the Utahraptor hypothesis of ambush or short burst predation capabilities. Imagine a dinosaur nearly the size of Utahraptor that looks like a dinosaur, but also like a bird (living dinosaurs of course) staring you down and ready to chase you for miles, providing you can outrun it. This is not a scenario I would welcome.
Possibly an "uncool" amalgamation of unattributed work I found in a number of places.
(C) Emily Willoughby (again) for certain though.

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