Elaphrosaurus
Skeleton assembly in the Berlin Museum of Natural History
Elaphrosaurus is a genus theropod dinosaur from the group of Ceratosauria that ( until possibly late Kimmeridgian to early Tithonian ) lived in East Africa during the Upper Jurassic.
Her remains were found during the German Tendaguru expeditions (1909-1913) in the vicinity of the hill Tendaguru in Tanzania and described in 1920 by the German dinosaur specialists Werner Janensch. Only species and therefore type species is Elaphrosaurus bambergi. The genus is known especially for a partial skeleton, which, among other things, the skull, forearm and hand and some pelvic bone is missing. It is by far the best-known theropods from Tendaguru. The name means " Light-footed lizard" (Greek elaphros - " nimble ", " light-footed ", sauros - " lizard" ), in reference to the slim body.
Features
Elaphrosaurus is considered very lightly built and fast runner. The cervical vertebrae were relatively long and resulted in a relatively long neck. Tibia, fibula and metatarsal bones were extended, while the upper arm was quite short. Werner Janenschs reconstruction of the holotype skeleton shows a length of approximately 5.35 meters and a waist of about 1.45 meters. This skeleton probably belonged to an adult animal, after which point the fusion of the cervical ribs with the respective vertebrae, the fusion of the vertebral arches with the vertebral bodies of the vertebrae and the merger of the sacrum. Of all the other Ceratosauria to Elaphrosaurus be distinguished by several unique features, including the strongly concave lower edge of the cervical vertebrae and the scapula, its width exceeds the height of the spine.
Finds and types
The holotype specimen (. HMN copy number Gr pp. 38-44 ) is a fragmentary skeleton; not recorded are the skull, forearm and hand, ribs, pubis, ischium, and the last caudal vertebrae. This skeleton is of Natural History to see the exhibition of the Berlin Museum. Some other isolated single finds from Tendaguru are also assigned Elaphrosaurus. Almost all fossils originate from the Middle Saurian layers from a single quarry (referred to as dd) north of Tendaguru near the settlement Kindope. The same quarry contained the remains of Dicraeosaurus, Giraffatitan and Giganotosaurus.
Ernst Stromer (1934 ) wrote Elaphrosaurus to three other findings, which he had discovered in the Bahariyya oasis in Egypt. These finds are now destroyed; using the parameters can, however, given the current state does not determine characteristics that may justify an assignment to the genus Elaphrosaurus.
Albert -Félix de Lapparent (1960 ) named two additional species from the Lower Cretaceous of Niger - Elaphrosaurus iguidiensis and Elaphrosaurus gautieri. While Elaphrosaurus gautieri is now regarded as a separate genus ( Spinostropheus ) Elaphrosaurus iguidiensis applies dubium than not be assigned, theropod and as a noun.
Peter Galton (1982 ) wrote Elaphrosaurus a humerus to from the North American Morrison Formation.
System
The phylogenetic relationships of Elaphrosaurus were long unclear. Initially introduced him Janensch Werner (1920, 1925) to the Coeluridae, a group in which at that time almost all small and lightly built theropod were collected. Franz Nopcsa (1928 ) suggested Elaphrosaurus as a representative of the Ornithomimidae off what by later authors ( Russell, 1972; Galton, 1982) was confirmed. This assignment was based primarily on the sleek and stretched, only a low Deltopectoralkamm having humerus. Only in the early 1990s, after the discovery and description of various representatives of the Abelisauridae, the membership has been recognized to the Ceratosauria.