Elaphrosaurus

Elaphrosaurus
	Skeleton assembly in the Berlin Museum of Natural History
Temporal occurrence
	Upper Jurassic (Upper Kimmeridgian to possibly Lower Tithonian )
	154.7 to 147.7 million years
Locations
	Tanzania ( Tendaguru formation );
Systematics
	Dinosaur (dinosauria)
	Lizard dinosaur (Saurischia)
	Theropoda
	Ceratosauria
	Elaphrosaurus
Scientific name
	Elaphrosaurus
	Janensch , 1920

Artistic life reconstruction of Elaphrosaurus bambergi

Elaphrosaurus is a genus of theropod dinosaur from the Ceratosauria group , whichlived in East Africaduring the Upper Jurassic (late Kimmeridgian to possibly early Tithonian ).

Their remains were during the German Tendaguru expeditions (1909-1913) near the hill Tendaguru in Tanzania found and in 1920 by the German dinosaur specialist Werner Janensch described . The only species and thus type species is Elaphrosaurus bambergi . The genus is best known for a partially preserved skeleton, which is missing the skull, forearm and hand and some pelvic bones. It is by far the best known theropod from Tendaguru. The name means "light-footed lizard" ( Gr. Elaphros - "nimble", "light-footed", sauros - "lizard"), alluding to the slim physique.

features

Elaphrosaurus is considered to be a very light and fast runner. The cervical vertebrae were relatively long and resulted in a relatively long neck. The tibia, fibula and metatarsal bones were elongated, while the upper arm was quite short. Werner Janensch's reconstruction of the holotype skeleton shows a length of about 5.35 meters and a hip height of about 1.45 meters. This skeleton probably belonged to an adult animal, as evidenced by 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 fusion of the sacrum. Elaphrosaurus can be distinguished from all other Ceratosauria by various unique features, including the highly concave lower edge of the cervical vertebrae and the shoulder blade, the width of which exceeds the height of the spine.

Finds and species

The holotype specimen (specimen number HMN Gr. Pp. 38-44) is a fragmentary skeleton; The skull, forearm and hand, ribs, pubic bone, ischium and the last caudal vertebrae have not survived. This skeleton can be seen in the exhibition of the Berlin Museum of Natural History . A few more isolated individual finds from Tendaguru are also assigned to Elaphrosaurus . Almost all of the fossils come from the Middle Dinosaurs from a single quarry (referred to as dd ) north of Tendaguru near the Kindope settlement. The same quarry housed the remains of Dicraeosaurus , Giraffatitan and Gigantosaurus .

Ernst Stromer (1934) attributed three other finds to Elaphrosaurus that he discovered in the Bahariyya oasis in Egypt. These finds are destroyed today; Based on the descriptions, however, according to the current state of the art, no characteristics can be determined which could justify an assignment to the genus Elaphrosaurus .

Albert-Félix de Lapparent (1960) identified two other species from the Lower Cretaceous of Niger - Elaphrosaurus iguidiensis and Elaphrosaurus gautieri . While Elaphrosaurus gautieri is now regarded as an independent genus ( Spinostropheus ), Elaphrosaurus iguidiensis is regarded as a theropod that cannot be further assigned and as a noun dubium .

Peter Galton (1982) attributed a humerus bone from the North American Morrison Formation to Elaphrosaurus .

Systematics

The relationship of Elaphrosaurus was long unclear. Werner Janensch (1920, 1925) initially placed him in the Coeluridae , a group in which almost all small and light theropods were collected at that time. Franz Nopcsa (1928) suggested Elaphrosaurus as a representative of the Ornithomimidae, which was confirmed by later authors (Russell, 1972; Galton, 1982). This assignment was based primarily on the slender and elongated humerus with only a low deltopectoral ridge. It was not until the early 1990s, after the discovery and description of various representatives of the Abelisauridae , that it was recognized as belonging to the Ceratosauria.

literature

Peter M. Galton : Elaphrosaurus, an ornithomimid dinosaur from the upper jurassic of north America and Africa. In: Paleontological Journal. Vol. 56, No. 3/4, 1982, ISSN 0031-0220 , pp. 265-275, doi : 10.1007 / BF02988803 .
Werner Janensch : About Elaphrosaurus bambergi and the megalosaurs from the Tendaguru layers of German East Africa. In: Meeting reports of the Society of Friends of Natural Sciences in Berlin. 1920, ISSN 0037-5942 , pp. 225-235, digitized .
Werner Janensch: The coelurosaurs and theropods of the Tendaguru layers of German East Africa. In: Werner Janensch: (Ed.): Scientific results of the Tendaguru expedition 1909–1912. New series series 1: The reptiles of the Tendaguru strata of German East Africa (= Palaeontographica. Supplement 7, series 1, part 1, ISSN 0085-4611 ). Delivery 1. Schweizerbart Stuttgart 1925, pp. 1-99.
Werner Janensch: An erected and reconstructed skeleton of Elaphrosaurus bambergi. With an addendum on the osteology of this coelurosaur. In: Werner Janensch: (Ed.): Scientific results of the Tendaguru expedition 1909–1912. New series series 1: The reptiles of the Tendaguru strata of German East Africa (= Palaeontographica. Supplement 7, series 1, part 1, ISSN 0085-4611 ). Delivery 3. Schweizerbart Stuttgart 1929, pp. 279–286.
Oliver WM Rauhut : The interrelationships and evolution of basal theropod dinosaurs (= Special Papers in Palaeontology. Vol. 69). Paleontological Association, London 2003, ISBN 0-901702-79-X .

Web links

Commons : Elaphrosaurus - collection of images, videos and audio files

Individual evidence

↑ ^a ^b ^c ^d ^e ^f ^g Matthew T. Carrano, Scott D. Sampson: The Phylogeny of Ceratosauria (Dinosauria: Theropoda). In: Journal of Systematic Palaeontology. Vol. 6, No. 2, 2008, ISSN 1477-2019 , pp. 183-236, here p. 202, doi : 10.1017 / S1477201907002246 .
↑ ^a ^b Oliver WM Rauhut: Post-cranial remains of "coelurosaurs" (Dinosauria, Theropoda) from the Late Jurassic of Tanzania. In: Geological Magazine. Vol. 142, No. 1, 1925, ISSN 0016-7568 , pp. 97-107, doi : 10.1017 / S0016756804000330 .
↑ Ben Creisler: Dinosauria Translation and Pronunciation Guide ( Memento of October 13, 2011 in the Internet Archive )
^ ^A ^b Janensch: The coelurosaurs and theropods of the Tendaguru strata of German East Africa. 1925.
^ Paul C. Sereno , Jeffrey A. Wilson, Jack L. Conrad: New dinosaurs link southern landmasses in the Mid-Cretaceous. In: Proceedings of the Royal Society. Series B: Biological Sciences. Vol. 271, No. 1546, 2004, ISSN 0950-1193 , pp. 1325-1330, doi : 10.1098 / rspb.2004.2692 .
↑ ^a ^b Peter M. Galton: Elaphrosaurus, an ornithomimid dinosaur from the upper jurassic of north America and Africa. In: Paleontological Journal. Vol. 56, No. 3/4, 1982, pp. 265-275.

[carrano08-1] ↑ ^a ^b ^c ^d ^e ^f ^g Matthew T. Carrano, Scott D. Sampson: The Phylogeny of Ceratosauria (Dinosauria: Theropoda). In: Journal of Systematic Palaeontology. Vol. 6, No. 2, 2008, ISSN 1477-2019 , pp. 183-236, here p. 202, doi : 10.1017 / S1477201907002246 .

[rauhut_2005-2] Oliver WM Rauhut: Post-cranial remains of "coelurosaurs" (Dinosauria, Theropoda) from the Late Jurassic of Tanzania. In: Geological Magazine. Vol. 142, No. 1, 1925, ISSN 0016-7568 , pp. 97-107, doi : 10.1017 / S0016756804000330 .

[creisler-3] Ben Creisler: Dinosauria Translation and Pronunciation Guide ( Memento of October 13, 2011 in the Internet Archive )

[janensch_1925-4] A ^b Janensch: The coelurosaurs and theropods of the Tendaguru strata of German East Africa. 1925.

[sereno-5] Paul C. Sereno , Jeffrey A. Wilson, Jack L. Conrad: New dinosaurs link southern landmasses in the Mid-Cretaceous. In: Proceedings of the Royal Society. Series B: Biological Sciences. Vol. 271, No. 1546, 2004, ISSN 0950-1193 , pp. 1325-1330, doi : 10.1098 / rspb.2004.2692 .

[galton_82-6] Peter M. Galton: Elaphrosaurus, an ornithomimid dinosaur from the upper jurassic of north America and Africa. In: Paleontological Journal. Vol. 56, No. 3/4, 1982, pp. 265-275.