Varanops

Skeletal reconstruction of Varanops brevirostris at the Museum of Natural History (University of Michigan)

• USA

• Varanops brevirostris Williston, 1911

Varanops (Greek " Warangesicht " ) refers to an extinct genus varanopider synapsids from the Early Permian of Texas and Oklahoma. The long over a meter animal strongly resembled in appearance to today living monitor lizards and fed probably by small vertebrates. First described in 1911 by Samuel W. Williston as a second species of the genus Varanosaurus, revised 1914 Williston his view, however, and ordered the kind Varanops brevirostris as type species of its own genus Varanops to.

While most Pelycosaurier were already extinct before, Varanops survived until the Kungurian and was one of the last representatives of this group. At the beginning of the Late Permian also Varanops died from possibly due to competition from Diapsiden and therapsids.

Locations

Well-preserved fossils of Varanops were found in Baylor County, Texas in Cacops - bonebed the Arroyo Formation, part of the Clear Fork group. Other three specimens are from the Garber Formation, part of the Sumner Group, in Comanche County, Oklahoma. In the Vale Formation of the Clear Fork Group, Taylor County, Texas, also a specimen was discovered. The specimen from the Arroyo lineup has bite marks that indicate a large, carrion-eating tetrapods. With some probability, these were a Dissorophoiden from the group of Temnospondyli. This can be inferred from the nature of the bite marks and a remarkably well-preserved tooth crown, which was in the front limbs of the fossil.

Description

Varanops is known with three complete skulls in poor condition and a well-preserved parts of the skull. The largest specimen has a lower jaw with a length of 170 mm, with the 24 - 28 teeth was occupied. In addition, they found three unoccupied alveoli ( alveolus ) on both sides of the mandible.

Varanops was a relatively large varanodontiner Varanopide, however, the skull appears comparatively short. Varanops had a pointed snout, which was narrow in the front part, however, widened the rear ( posterior). The occiput is inclined as with other Varanopsidae forward. A large infra pace Ralf Rochester was also available.

Occupied with six teeth Zwischenkieferbein is rounded, similar to derivative works of the Ophiacodontidae and Sphenacodontidae. The middle front teeth were there longer than the side ( lateral ). Be found on the teeth, unlike the Myctosaurinae no teeth ( Serra TION ). This feature divides Varanops with other Varanodontinen as Varanodon and Aerosaurus.

The neck ribs were not very stable, as opposed to the rear ribs, which are also larger.

Classification

Varanops is the type genus of the Varanopidae represents a cladistic analysis of Campione and Reisz suggests that Varanops a derived form the Varadontiden figured a sister taxon of the clade formed by Varanodon and Watongia.