Fig. 6From: Dimetrodon Is Not a Dinosaur: Using Tree Thinking to Understand the Ancient Relatives of Mammals and their Evolutiona The right side of the skull and jaw of Eothyris (MCZ 1161) and eothyridid synapsid. Eothyris is probably a good model for the common ancestor of all synapsids. b Skeleton of Edaphosaurus, an edaphosaurid synapsid. Edaphosaurus is one of the oldest known terrestrial vertebrate herbivores. This skeleton is on display at The Field Museum. Images are not to scaleBack to article page