Procolophonidae

Sclerosaurus in a live reconstruction

• North America
• Europe
• Asia
• Africa
• Antarctica

The Procolophonoidea are an extinct group of Para reptiles that lived about 60 million years, from the Upper Permian to Upper Triassic and during the Triassic produced a beachtlichten species richness. Fossil evidence found on most continents (except South America and Australia).

Anatomical features

A characteristic feature of the skull of the group is an extended more or less behind the eye orbit. This pseudo skull window in the Advanced anapsiden Procolophonoidea anchoring the jaw muscles. A large indentation in the quadrate and the narrow stapes in the middle ear suggest the presence of an eardrum ( tympanum ), which would have allowed the Procolophonoidea to hear high frequency sounds.

The early Procolophonoidea had a thin skull and numerous small, needle-like teeth. Procolophon from the Lower Triassic of South America and Antarctica was 30 to 40 inches long, later forms were much larger and had an enlarged and thickened at various locations skull. Horn -like spines on Quadratojugalen the occiput and the lower cheek region were possibly the defense. The number of lateral teeth widened this later species is low. The blunt, peg -like molars came when biting occlusion, probably an adaptation to high-fiber plant foods but also the consumption of arthropods ( Arthropoda ) with well developed cuticle appears to be possible with this dentition.

Body skeleton

The postcranial ( = behind the skull lying ) skeleton of the animals is primitive. The laterally projecting legs allowed a creeper. The fastening of the tank is increased by a third cross leg rib. The neural arches of the vertebrae are expanded. The wider feet suggest a certain grave activity.

System

The systematic position of the Procolophonoidea is not fully understood. In the past they were considered as a group close to the reptiles, today to set the group to the para reptiles. Their position within this group of reptiles is the subject of scientific debate, some consider it the closest relatives of turtles, while others think this would meet the Pareiasauridae to.