''Dicraeosaurus'' (Gr. , ' "bifurcated, double-headed" + Gr. , ' "lizard") is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

diplodocoid Diplodocoidea is a superfamily of sauropod dinosaurs, which included some of the longest animals of all time, including slender giants like ''Supersaurus'', ''Diplodocus'', ''Apatosaurus'', and ''Amphicoelias''. Most had very long necks and long, ...

sauropod Sauropoda (), whose members are known as sauropods (; from '' sauro-'' + '' -pod'', 'lizard-footed'), is a clade of saurischian ('lizard-hipped') dinosaurs. Sauropods had very long necks, long tails, small heads (relative to the rest of their bo ...

dinosaur Dinosaurs are a diverse group of reptiles of the clade Dinosauria. They first appeared during the Triassic period, between 243 and 233.23 million years ago (mya), although the exact origin and timing of the evolution of dinosaurs is t ...

that lived in what is now

Lindi Region Lindi Region (''Mkoa wa Lindi'' in Swahili) is one of Tanzania's 31 administrative regions. The region covers an area of . The region is comparable in size to the combined land area of the nation state of Sri Lanka. The regional capital is the m ...

Tanzania Tanzania (; ), officially the United Republic of Tanzania ( sw, Jamhuri ya Muungano wa Tanzania), is a country in East Africa within the African Great Lakes region. It borders Uganda to the north; Kenya to the northeast; Comoro Islands and ...

during the late

Jurassic The Jurassic ( ) is a Geological period, geologic period and System (stratigraphy), stratigraphic system that spanned from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period, approximately Mya. The J ...

period. The genus was named for the neural spines on the back of its neck. The first fossil was described by paleontologist

Werner Janensch Werner Ernst Martin Janensch (11 November 1878 – 20 October 1969) was a German paleontologist and geologist. Biography Janensch was born at Herzberg (Elster). In addition to Friedrich von Huene, Janensch was probably Germany's most imp ...

in 1914.

Description

Unlike most diplodocoids, ''Dicraeosaurus'' had a comparatively large head with a relatively short and wide neck. The neck contained 12 unusually short

vertebrae The spinal column, a defining synapomorphy shared by nearly all vertebrates,Hagfish are believed to have secondarily lost their spinal column is a moderately flexible series of vertebrae (singular vertebra), each constituting a characteristic i ...

, likely indicating a low-level browser of vegetation no more than off the ground. ''Dicraeosaurus'' also lacked the "whiplash" tail tip typical of diplodocoids. It was smaller than many other diplodocoids, at only in length and , though this still makes it among the larger known members of the family Dicraeosauridae. The genus is notable for the rather tall neural spines protruding from its vertebrae, which it is named for. They were not straight as in some members of the family, instead forming a rough "Y" shape. These spines likely provided muscle attachment points.

Palaeoecology

''Dicraeosaurus'' was a mid-sized herbivore for its ecosystem, found in the

Tendaguru Formation The Tendaguru Formation, or Tendaguru Beds are a highly fossiliferous formation and Lagerstätte located in the Lindi Region of southeastern Tanzania. The formation represents the oldest sedimentary unit of the Mandawa Basin, overlying Neoproter ...

, which dates to the Late Jurassic. The rocks also yield fossils of ''

Giraffatitan ''Giraffatitan'' (name meaning "titanic giraffe") is a genus of sauropod dinosaur that lived during the late Jurassic Period (geology), Period (Kimmeridgian–Tithonian stages) in what is now Lindi Region, Tanzania. It was originally named as an ...

'' and ''

Kentrosaurus ''Kentrosaurus'' ( ; ) is a genus of stegosaurid dinosaur from the Late Jurassic in Lindi Region of Tanzania. The type species is ''K. aethiopicus'', named and described by German palaeontologist Edwin Hennig in 1915. Often thought to be a " pri ...

''. As there was a distinct difference in size between these dinosaurs, they would probably have browsed on vegetation at different levels and therefore competition between them was likely rare.

References

External links

Quick facts
{{Portal bar, Dinosaurs Dicraeosaurids Late Jurassic dinosaurs of Africa Fossil taxa described in 1914 Taxa named by Werner Janensch Tendaguru fauna