Caseidae

Life image of Cotylorhynchus

• Eurasia
• North America

The Caseidae were herbivorous synapsids from the group of Pelycosaurier. So you're after classic view " reptiles ", but related to those animals that make up the " mammal-like reptiles " and finally the mammals have evolved. They lived in the Permian period about 290 to 260 million years.

Description

The body size of the Caseidae varies considerably, the smaller representatives were about one meter, while the larger species reaching a length of about four meters and an estimated weight of 500 kilograms.

The skull of these animals was short and had a bent forward basic form. The typical for the synapsids skull window was very large, to allow room for a strong jaw muscles. The nostrils were greatly enlarged. The teeth were uniform ( homodont ), they had a blunt shape with wavy edges. At the mouth roof, there was a series of smaller teeth, which - since corresponding structures are absent on the lower jaw - probably worked with a rough, muscular tongue and so the inclusion of hard parts of plants allowed. The body skeleton was barrel-shaped, probably to make room for a well-developed digestive tract for the fermentation of plant food. The limbs were strong, compared to the rest of the body, the head, the neck was very small and short.

Spatial and temporal classification

The oldest finds date from the early Permian, and they are among the few Pelycosauriern that are known not only from North America - so these animals were discovered, for example, in France and Kazakhstan fossils. The recent finds from the late Mittelperm.

System

Systematically form the Caseidae with the Eothyrididae the group of Caseasauria, which stands at the base of the synapsids and which forms the sister group of the Eupelycosauria, giving rise to the therapsids have (the " mammal-like reptiles " ), and finally developed the mammals.

Genera

• Angelosaurus
• Casea
• Caseopsis
• Caseoides
• Cotylorhynchus
• Ennatosaurus
• Knoxosaurus
• Oromycter