Dicraeosaurus

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Dicraeosaurus
Temporal range: Late Jurassic, 155–150Ma
Dicraeosaurus Berlin.jpg
Dicraeosaurus skeleton
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Superorder: Dinosauria
Order: Saurischia
Suborder: Sauropodomorpha
Family: Dicraeosauridae
Subfamily: Dicraeosaurinae
Janensch, 1929
Genus: Dicraeosaurus
Janensch, 1914
Species
  • D. hansemanni Janensch, 1914 (type)
  • D. sattleri Janensch, 1914

Dicraeosaurus (Gr. δικραιος, dikraios "bifurcated, double-headed" + Gr. σαυρος, sauros "lizard") is a genus of small diplodocoid sauropod dinosaur. It was named for the spines on the back of the neck. The first fossil was described by paleontologist Werner Janensch in 1914.

Description[edit]

Restoration of D. hansemanni

Unlike most diplodocoids, Dicraeosaurus had a large head with a relatively short and wide neck. The neck contained 12 unusually short vertebrae, so it could probably browse vegetation only from ground level to a height of about 3 metres (9.8 ft).[1] It also lacked the whiplash tail that other diplodocids had. It was smaller, at only reached 41 feet (12 m) in length. It gets its name, which means two-forked lizard, from the spines that came from the vertebrae. They were not straight as in some members of the family. Each one was “Y” shaped, like a fork. These spines also provided muscle attachment points.[2]

Palaeoecology[edit]

Dicraeosaurus lived in the Late Jurassic. It was herbivorous; however, it didn’t compete with other dinosaurs for vegetation. Fossils have been discovered in the rocks of Tendaguru Hill in Tanzania. The rocks also yield fossils of Giraffatitan and Kentrosaurus. As there was a distinct difference in size between these animals, they would probably have browsed for vegetation at different levels, allowing them to co-exist without significant competition.[2]

Classification[edit]

Dicreosaurids shown to scale
Restoration of the head

The following cladogram follows an analysis by Sereno et al. in 2007.[3]

Diplodocoidea

Diplodocidae

Apatosaurus



Diplodocus




Suuwassea


Dicraeosauridae

Amargasaurus




Brachytrachelopan



Dicraeosaurus





Rebbachisauridae

Histriasaurus




Rebbachisaurus






Cathartesaura



Limaysaurus




Zapalasaurus





Demandasaurus



Nigersaurus







References[edit]

  1. ^ Benton, Michael J. (2012). Prehistoric Life. Edinburgh, Scotland: Dorling Kindersley. p. 270. ISBN 978-0-7566-9910-9. 
  2. ^ a b Palmer, D., ed. (1999). The Marshall Illustrated Encyclopedia of Dinosaurs and Prehistoric Animals. London: Marshall Editions. p. 132. ISBN 1-84028-152-9. 
  3. ^ Sereno PC, Wilson JA, Witmer LM, Whitlock JA, Maga A, et al. (2007) Structural Extremes in a Cretaceous Dinosaur. PLoS ONE 2(11): e1230.

External links[edit]