STL Science Center

STL Science Center

28 November 2014

Therapsids and Other Early Mammals

©Dmitry Bogdanov
Because of the last month's adventure into the history of the rhinoceros (and the intermediate horse/rhinoceros Megacerops) I have decided that we need to look, as we have done at least once and in a cursory manner, at the other end of mammalian evolution. We will not specifically attempt to trace any single line, however, a fairly comfortable sampling of very early mammals should suffice to examine where some of the familiar forms of today initially took root.

To begin this journey we will look, not in chronological order, but in the order of what I personally find most interesting (unless I get some good suggestions for the future as time goes on). This week, therefore, I have decided that the first ancient mammal to be discussed during December is the genus Moschops. Moschops consists of 4 recognized species, 2 of which are considered questionable. The remains of Moschops species have been recovered from the Karoo Basin of South Africa, long known and famous for its mammalian riches. Moschops was a large, hefty Therapsid Dinocephalian herbivore that possessed a uniquely opened elbow joint that allowed Moschops to move much more like a modern mammal and less like a crawling, sprawling reptile. The skeleton of the animal has led to the inference that Moschops used this newly adapted joint system to move the massive body that the skeleton represents as it fed, seemingly without end, on the low nutritive quality of the cycads and ferns that grew around it. Overall, it is a squat, but gigantic animal. It looks almost uninteresting, but I promise it has many more interesting characteristics to be seen over the week to come.

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