Today’s illustration comes from “Ontogenetic mechanisms of size change: implications for the Lilliput effect and beyond” in the journal Paleobiology. The paper concerns such topics as ontogeny, phylogeny, heterochrony, allometry, and taphonomy, and can be viewed here or here. (The journal is subscription-only, but maybe you are one of the lucky few who has access!)
One of the examples considered in the study is an animal called Lystrosaurus, which lived during the Permian and Triassic. It was once considered a reptile, but is now know to have been more closely related to the mammals.
Although Lystrosaurus is not nearly as well known as some of the more charismatic prehistoric animals, it did gain a certain measure of fame because its fossils are found on what are now several separate continents, thus providing evidence for the theory of continental drift.
I never knew that Lystrosaurus looked like such a doofus.
