Here’s another colored-pencil-on-colored-paper drawing; this time it’s a reconstruction of a long-extinct animal. Seymouria sanjuanensis was a tetrapod that lived during the early Permian period, more than 270 million years ago, long before the dinosaurs, pterosaurs, plesiosaurs, and other newcomers had arrived on the scene. It was a stocky little lizard-like creature about two feet long, similar in size and shape to the modern blue-tongued skinks. Its sturdy skeleton, with prominent attachment points for muscles, was adapted for terrestrial life. Its teeth were sharp; it likely preyed on the numerous insects and other arthropods that flourished in the Permian, and perhaps ate small vertebrates as well.
The major paleontological interest in Seymouria has been in its relationship to the amniotes (the vertebrate group that includes reptiles, birds, and mammals). Many paleontologists in the 20th century considered Seymouria a representative of the transition from the “amphibian” grade of tetrapods to the “reptile” grade. It was often treated as a sort of ur-reptile, from which the anatomies of early true reptiles and synapsids could be derive. More recent research indicates that Seymouria may not be closely related to amniotes at all, and that its similarities to them are independently acquired, perhaps due to the common constraints of terrestrial life.