Diadectomorpha

Live reconstruction of Diadectes, a Diadectidae from the Early Permian of North America

• Europe
• North America

The Diadectomorpha are a group of extinct land vertebrate animals that exhibit both characteristics of amphibians and reptiles. They lived in the eras of the Upper Carboniferous and Early Permian ( Cisuralium ) on the super-continent Laurussia.

Among them are large, up to two meters long and partially aquatic living carnivores such as Limnoscelis, and also the first large, herbivorous terrestrial vertebrates. Diadectes was three meters long, had a highly specialized skull with a secondary palate and molariforme molars, so one assumes that he fed on tough plants.

System

Outer systematics

Originally, the taxon " Cotylosauria " was set up as the most primitive order of reptiles for the Diadectomorpha. The taxon both amphibians and primitive amniotes have been assigned. Meanwhile, the " Cotylosauria " have proved to be paraphyletic. The Diadectomorpha regarded today as the sister group of the amniotes and presented with them in the taxon Reptiliomorpha, which is the sister group of amphibians.

• Land vertebrates ( Tetrapoda ) Amphibia
• Reptiliomorpha Amniota ( reptiles, birds, mammals )
• Diadectomorpha

After an investigation of the occipital region of Limnoscelis Diadectes and the systematic position of the Diadectomorpha was re-evaluated. They should be the sister group of the Synapsida, a taxon which also includes the mammals. This means that the Diadectomorpha are amniotes. The unnamed clade formed by the Diadectomorpha and Synapsida is the sister group of reptiles.

• Land vertebrates ( Tetrapoda ) Amphibia
• Amniota Reptiles
• Unnamed clade Diadectomorpha
• Synapsida

Inside systematics

• Diadectomorpha Limnoscelidae Limnoscelis
• Limnosceloides
• Limnoscelops
• Limnostygis

• Tseajaiidae

• Desmatodon
• Diadectes
• Diasparactus
• Orobates
• Stephanospondylus