Therizinosaurus

Model of a feathered Therizinosaurus cheloniformis

• Mongolia

• Therizinosaurus cheloniformis Maleev, 1954

Therizinosaurus ( "Sense lizard" ) is a genus theropod dinosaurs within the Therizinosauridae.

Therizinosaurus lived during the Late Cretaceous (Upper Campanian to Lower Maastrichtian ) and was one of the last and largest representatives of its unique group of Therizinosauridae. Of this kind only a few fossil bones are known, including huge claws of the hands, which led to the naming. Its total length is estimated to be 9 meters.

Discovery and species

The first fossil remains of Therizinosaurus were discovered in 1948 by a joint Russian -Mongolian expedition in the in the southwest Mongolia Nemegt lineup. The researchers dug several giant claws from up to one meter in length. 1954 described Yevgeny Alexandrovich Malejew (international: EA Maleev ) for a copy from Mongolia this find as how he believed at the time, large turtle -like reptile, because he believed in the mouth it was the ribs of such an animal. ( This is the basis in the species name T. cheloniformis - " turtle shaped .") It was not until in the early 1950s further expeditions more fossils, including more claws, but also front and rear limbs was dug out clearly what these creatures were. Later finds in northern China allowed paleontologists finally to reconstruct the basic structure of the skeleton. It became clear that it was not a turtle but a dinosaur.

The discovery that it was at the enigmatic theropod Segnosauridae how Erlikosaurus and Segnosaurus, also an assignment of the Therizinosaurus was possible. There have been various theories about the origin of the Segnosauridae. Some researchers thought they were descendants of the Sauropodomorpha. But well-preserved new finds, such as the method disclosed by Alxasaurus in 1993 and in 1996 Beipiaosaurus important details, such as feet and skull and the bird-like pelvis of these primitive members of the dinosaur family. Thus, it was confirmed that it was in the Segnosauridae including Therizinosaurus to members of a group of theropods which was now referred to as Therizinosauridae. Therizinosauridae were therefore well-developed plant-eating theropod from the group of Maniraptora.

Features

Although so far only incompletely preserved fossil remains have been preserved by Therizinosaurus, it is possible on other species of the family Therizinosauridae to make inferences on the shape of the Therizinosaurus. He probably had, like the other members of the family, a small skull and a long neck. He walked on two legs and the width of the pelvis other Therizinosauridae indicates a large, thick hull. His arms reached a length of 2.5 m. His hind limbs ended in four -bearing, Strengthening toes, how they differ from the feet of other theropods, and the first toe was designed as a dewclaw.

The most striking feature of Therizinosaurus were the huge claws on the three fingers of his hands. The biggest claws found so far are incomplete, but they probably reached a length of about one meter.

Paleobiology

The feeding habits of Therizinosaurus are unknown, since no skull remains have been found, could provide clues to the diet. However, as other Therizinosauridae he was probably primarily an herbivore. The claws of the Therizinosaurus may have served different purposes, to draw such as the defense against predators such as Tarbosaurus is alive at the same time, area or Balzkämpfen among themselves or to eat leafy branches to the mouth. Perhaps the claws were also all these purposes.