Science Art: Geosaurus, by Samuel Wendell Williston.

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This is Geosaurus, recently outed in the pages of Discovery News as “the T. Rex of the deep”:

What’s more, metriorhynchids, the extinct relatives of today’s crocodiles, had a killing skill that T. Rex lacked: The death roll. The creatures would sink their teeth into prey and then spin their bodies in the water to tear out large chunks of flesh.

More than 100 years ago, one of these cuddly creatures was painted by Samuel Wendell Williston, the paleontologist who first suggested that birds learned to fly by running (on the ground) rather than jumping (from tree to tree). As a paleontologist, he put forward a heuristic: Over time, creatures tended to have fewer parts and more-specialized parts. Instead of a mouth full of lots of crude, spike-like teeth, large predators would develop, over thousands of generations, a tidy row of efficient, razor-sharp fangs, for example.

Williston was also medical examiner, geologist, university administrator and not too bad with a paintbrush.