Prionosuchus
Artistic reconstruction of a live Prionosuchus plummeri
Prionosuchus was a primitive land vertebrates from the group of Temnospondylen. Highly fragmented fossil remains from the Late Permian were found in the Pedra do Fogo Formation in northeastern Brazil. There is only one valid way Prionosuchus plummeri. With an estimated length of nine meters Prionosuchus is the largest ever living on earth amphibian.
Features
Prionosuchus was described in 1948 based on a snout fragment, a partially preserved lower jaw and a femur through the Brazilian paleontologist Llewellyn Price. The rostrum of the holotype has a length of 34.5 cm and above the interface between Zwischenkieferbein maxilla and a height of 2.0 cm and a width of 2.3 cm. Behind this interface the rostrum is getting wider, up to 3.1 cm at its base with a height of only 1.7 cm. Price estimated half a meter as the length of the entire skull, which was similar to the recent Gangesgavials with the long narrow snout. The 35 mm wide tip of the snout was covered with large, the rest of the nose with medium-sized conical canines. Depending on a Fang couple lying on the palatine bone in front of the internal nares and the vomer behind the inner nostrils.
During an excavation in 1972, skull fragments, vertebrae, ribs, shoulder blades, Cleithrum, clavicle, ilium, ischium and femur of a much larger specimen were found. The tip of the snout has a width of 10 cm, while that of the holotype is only 3.5 inches wide. Thus, the length of the skull is estimated at large copy to 1.6 meters. Like other, better known as Archegosauridae Archegosaurus and Platyoposaurus had Prionosuchus probably an elongated body and a long tail but small limbs. The femur incomplete obtained can not have been more than 13 cm with a maximum diameter of 1.5 cm. Compared with a five -meter-long Gavial whose skull has a length of 83 cm, Prionosuchus could have reached a length of about nine meters, which was significantly longer than Eogyrinus and Mastodonsaurus, the next larger amphibians.
Prionosuchus swam probably the type of crocodiles by undulating movements of the trunk and tail and fed on larger aquatic vertebrates. As with Gavial the narrow snout reduced the resistance of the water when snapping.
System
Prionosuchus belongs to the group of Archegosauridae and, like the other genera of the family, a long, narrow skull and abutting lacrimal and frontal bones, which referred to by the U.S. paleontologist Alfred Romer diagnostic features of Archegosauridae.