The Permian was the last period of the Paleozoic Era; it ended with the most severe mass extinction in Earth’s history. This period was a time of great diversification and experimentation by a number of plant and animal clades, only a few of which made it through the great extinction to be the founders of the Mesozoic flora and fauna. I am working on illustrations of some of these organisms and landscapes from the end of multicellular life’s first great flowering.
The Wellington Formation of Kansas and Oklahoma is best known for its exceptionally preserved insect fossils, but it also has yielded many plants and vertebrates. This scene is based on fossils from a handful of Wellington Formation sites in the vicinity of Perry, Oklahoma. These sites record an estuarine locality; members of several major vertebrate clades are present.
The blue fishes are Platysomus striatus, a “palaeoniscoid” or basal actinopterygian (Actinopterygii include most living fishes, but was only a modest component of Permian ichthyofaunas). They are swimming about the submerged trunk of an early conifer washed in from the uplands.
In the lower right is the lungfish Gnathorhiza serratus; lungfishes were far more widespread and diverse in the Permian than they are today. It is poking beneath a forked frond of the probable seed-fern Gigantopteridium americanum.
At bottom center are two adults of the temnospondyl Trimerorhachis insignis. One individual is disgorging juveniles from its pharyngeal brood pouches; this is based on an individual found with tiny bones of the same species preserved in the region where its internal gills would have been.
Above the Trimerorhachis is the famous boomerang-headed nectridean Diplocaulus magnicornis. The function of its bizarre skull is still debated; various authors have suggested it improved its maneuverability while swimming, protected its gills, or kept it from being swallowed by predators.
Finally at top right we see an animal only known from Perry, the early diapsid reptile Dictybolos tener. Little has been published on this animal, though it is apparently known from many specimens. It is thought to have been a piscivore (its genus name means “fisherman”).