|Upper Perm to Lower Triassic|
|260.4 to 245 million years|
|von Huene , 1914|
The Proterosuchidae are a group of crocodile-like reptiles that lived from the Upper Permian to the Lower Triassic . The Proterosuchidae were formerly considered the most primitive members of the Archosaurs , the namesake of this taxon, Archosaurus , is a Proterosuchid. Today, because of their many primitive features, they are placed in the Archosauriformes .
The premaxillary bone at the tip of the upper jaw protruding and overhanging the lower jaw is characteristic of the animals . In front of the eye there is a large, additional cranial window , the antorbital window , which is delimited by the maxillary , lacrimale and jugale and probably served to reduce weight. The antorbital window is a characteristic of all later archosaurs, including dinosaurs . Otherwise the skull is characterized by primitive features, some skull bones of the primitive diapsids are still present and the wing bone (pterygoid) is still dentate.
The elongated body of the Proterosuchidae was crocodile-like and their legs kept the animals splayed sideways, with no tendency to an improved position under the body. The vertebrae had long transverse processes . In the shoulder girdle , the shoulder blade and raven beak were clearly separated. The hand bones were barely ossified, the number of toe joints is unknown. The foot is very similar to that of primitive Archosauromorpha such as the Protorosauria , the Rhynchosauria or the Trilophosaurus .
- Family Proterosuchidae
- Robert L. Carroll : Paleontology and Evolution of the Vertebrates. Thieme, Stuttgart et al. 1993, ISBN 3-13-774401-6 .
- Palæos Proterosuchidae
- The Paleobiology Database Proterosuchidae