Malawisaurus (meaning "Malawi lizard") is an extinct genus of titanosaurian sauropod dinosaur. It is known from the Dinosaur Beds of northern Malawi, which probably date to the Aptian stage of the Early Cretaceous. The type species is M. dixeyi and the specific name honours Frederick Augustus Dixey.
Discovery and naming
Malawisaurus dixeyi was originally described in 1928 by Sidney H. Haughton as a
species of
Gigantosaurus (an invalid name for the
diplodocid currently known as
Tornieria). Haughton considered it closely related to the species
G. robustus (later the
type species of
Janenschia). The holotype was discovered in the "
Dinosaur Beds" of Malawi (then known as the
Nyasaland),
[Dixey, F. (1925). The discovery of fossil reptiles. Annual Report of the Geological Survey Department for the Year 1924, Nyasaland Protectorate 1924:7] which are usually considered to be of
Barremian-
Aptian age based on K–Ar dating, though they have also been suggested to be Late Cretaceous in age based on the vertebrate assemblage.
In 1993 it was placed in the newly named genus
Malawisaurus by Louis L. Jacobs and colleagues, based on newly collected material from the locality.
[L. L. Jacobs, D. A. Winkler, W. R. Downs and E. M. Gomani. 1993. New material of an Early Cretaceous titanosaurid sauropod dinosaur from Malawi. Palaeontology 36(3):523-534] The
holotype is SAM 7405, a partial skeleton and its type locality is
Mwakasyunguti.
Malawisaurus is not known outside of Africa - however, an isolated tooth resembles those associated with Malawisaurus and was found in the Late Cretaceous (Cenomanian)-aged Alcântara Formation of Brazil according to a report in 2007.It is currently listed as "Titanosauria indet., possibly Malawisaurus .sp".
Description
Relatively small by sauropod standards,
Malawisaurus reached lengths of about , and weighed about .
In 2020 it was given a smaller estimation of 11 meters (36 ft) and 2.8 tonnes (3.1 short tons).
Like some other titanosaurs, ossicles have been found which are believed to represent dermal scutes that covered the skin.
The vertebrae from the middle part of its tail had elongated centra.
Classification
By definition,
Malawisaurus has to be the most basal lithostrotian. The cladogram below follows Franca
et al. (2016).
See also
Footnotes
-
S. H. Haughton. 1928. On some reptilian remains from the Dinosaur Beds of Nyasaland. Transactions of the Royal Society of South Africa 16:67-75
-
Paul, Gregory S. (2010) The Princeton Field Guide to Dinosaurs.
-
Tidwell, V., Carpenter, K. & Meyer, S. 2001. New Titanosauriform (Sauropoda) from the Poison Strip Member of the Cedar Mountain Formation (Lower Cretaceous), Utah. In: Mesozoic Vertebrate Life. D. H. Tanke & K. Carpenter (eds.). Indiana University Press, Eds. D.H. Tanke & K. Carpenter. Indiana University Press. 139-165.
External links
