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Showing posts from June, 2007

Jaw biomechanics of Smilodon fatalis

Biomechanically, Smilodon fatalis is an interesting animal. Where most extant felids have big strong canines, S. fatalis had long flat ones.

This implies that Smilodon would not have been capable of the same kind of precision biting that modern cats employ. Struggling with prey to deliver a fatal bite to the nape of the neck and dislocating the cervical vertebrae would result in the canines contacting with bone. The long flattened canines of Smilodon probably would not have withstood that kind of load.

The canines of Smilodon don't look like stabbing teeth like in modern cats, instead they look more like slicing teeth - like in Komodo dragons.
To the left is a tiger skull for comparison. The tiger has a lower longer face, larger eyes, and above all has pronounced zygomatic arches. Smilodon on the other hand had smaller zygomatic arches. This reduced the amount of available space for the temporalis muscle thus reducing the overall muscle force.

The tiger also has huge coronoid process…

Megalosaur

This is some kind of a megalosaur I drew some time ago. I think it's supposed to be a Dubreuillosaurus, but I didn't really bother with any anatomical accuracy so I just call it a megalosaur.

Anyway, megalosaurs are interesting. They're usually agreed to be basal tetanuran theropods and sister-taxon to spinosaurs, together forming the Spinosauroidea. But the intrarelationship among the Megalosauridae is a mess. In short no one really knows which dinosaur is more closely related to the other. This is inevitable to a certain extent due to the fragmentary nature of many megalosaur specimens but also because of the historical treatment of 'megalosaurs' being kind of a wast basket for theropod fossils of uncertain affinities.