Aralosaurus

• Kyzylorda (Kazakhstan )

Aralosaurus ( "lizard from the Aral Sea " ) was a genus of dinosaur from the ornithopoder form- rich group of hadrosaur, during the Late Cretaceous (late Campanian ) in front of about 76 and 72 million years existed. Only species described is Aralosaurus tuberiferus.

Finds

Fossils of the genus were found in the Beleutinsk Formation in central Kazakhstan near the Aral Sea. The holotype with the catalog number 2229/1 is a partially preserved skull. In the same horizon in which the holotype was found, there were also some vertebrae, limb bones and individual teeth, probably belonging to different copies. The teeth, however, are identical to those of the holotype and thus it can be assumed that also included the other bone Aralosaurus. Moreover, even the rear part of a very small right half of the mandible was found, which is 4.5 inches long and 3 inches high and must belong to a very young specimen.

Features

The skull is moderately wide in the area of ​​the zygomatic bone. The nasal bone is only partially preserved in rising to an almost right angle and then forms a downward arc. The frontal bone forms a very small part of the bony orbit. The lacrimal bone is very large. An elliptical Fontanelle limited nasal bone and the frontal bone. The orbit is larger than the infra pace Ralf Rochester and has the shape of an almost round the oval. The Supra pace Ralf Rochester is small. The rear end of the postorbital bone end in three peaks. The square leg is bent on the upper side. The maxilla is short and high, do not get the premaxilla. The upper jaw had a very broad peak and contained about 30 rows of teeth. On the front and the rear edge of each tooth is about 20 little bumps were. The teeth of the lower jaw had an additional cusp row.

Comparing the skull length of 65 inches with the other hadrosaurs, so Aralosaurus must have been about 6.5 meters long and was a medium-sized hadrosaur. The skull, however, could have belonged to a young animal, as the sutures are not completely grown together.

System

Aralosaurus heard within the hadrosaur to the subfamily Hadrosaurinae who had no crests on their skulls. He stands near Bactrosaurus, Lophorhothon, and Kritosaurus. From Bactrosaurus it differs by the shape of the nasal bone, the smaller Supra pace Ralf Rochester, a short, high pine, and in the number of teeth. Differences to Lophorhothon are the little Supra pace Ralf Rochester and the narrow infra pace Ralf Rochester and the greater number of teeth.