Dandakosaurus

Dandakosaurus (meaning "Dandakaranya lizard") is a genus of extinct averostran theropod dinosaur from the Kota Formation, Andhra Pradesh, India. It lived 183 to 175 million years ago from the latest Pliensbachian to the late Toarcian stages of the Early Jurassic. Little is known about the genus and some paleontologists consider it to be a nomen dubium.

Dandakosaurus Temporal range: Early Jurassic (Latest Pliensbachian-late Toarcian), 183–175 Ma PreꞒ Ꞓ O S D C P T J K Pg N
Dandakosaurus restored as a Megalosauroid
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Clade:	Dinosauria
Clade:	Saurischia
Clade:	Theropoda
Superfamily:	†Megalosauroidea
Genus:	†Dandakosaurus Yadagiri, 1982
Species:	†D. indicus
Binomial name
†Dandakosaurus indicus Yadagiri, 1982

Discovery and naming

The holotype is partial pubis, GSI 1/54Y/76, discovered in the Kota Formation of India between 1958 and 1961 and was described as an indeterminate carnosaur in 1962.^[1][2] Other material referred to the genus include dorsal vertebrae, caudal vertebrae, a tooth and a partial ischium. The type species, D. indicus, was named by Yadagiri in 1982.^[3][2]

Description

The tooth was described as being recurved and heavily compressed. The distal carina possessed small denticles.^[3] The carinae were positioned centrally and the tooth was subsymmetrical labial and distal profiles.^[4] The dorsal vertebrae lack pleurocoels and opisthocoelous. The caudal vertebrae bore depressions on the lateral sides. It was amphicoelous and had a keel on its ventral side. It is possible that the vertebrae belong to a sauropodomorph. The obturator fenestra of the pubis is absent, instead being an obturator notch.^[5] The pubis is unique in that it points ventrally, unlike the usual forward-facing condition seen in Saurischians, giving it a mesopubic condition.^[6]

Classification

Dandakosaurus is currently classified as Averostra incertae sedis, variously suggested to be a basal ceratosaur^[7] or basal tetanuran.^[2][5][8]

See also

• Timeline of ceratosaur research

References

1. Jain, R. and Chowdhury, R. (1962). A new vertebrate fauna from the Early Jurassic of the Deccan, India. Nature. 194(4830): 755-757.
2. Olshevsky, G. (1991). "A revision of the parainfraclass Archosauria Cope, 1869, excluding the advanced Crocodylia" (PDF). Mesozoic Meanderings 2. San Diego: 196.
3. Yadagiri, P. (1982). Osteological studies of a carnosaurian dinosaur from the Lower Jurassic Kota Formation: Andhra Pradesh. Geological Survey of India (Progress Report for Field Season Programme 1981-1982), Regional Palaeontological Laboratories, Southern Region. 7 pp.
4. Sharma, Archana; Hendrickx, Christophe; Singh, Sanjay (2023-01-23). "First Theropod Record from the Marine Bathonian of Jaisalmer Basin, Tethyan Coast of Gondwanan India". Rivista Italiana di Paleontologia e Stratigrafia. 129 (1). doi:10.54103/2039-4942/18306. ISSN 2039-4942.
5. "Megalosauroidea".
6. https://www.researchgate.net/publication/380168073_Triassic-Jurassic_dinosaurs_from_India_their_ages_and_palaeobiogeographic_significance ^{[bare URL]}
7. Reolid, M.; Ruebsam, W.; Benton, M. J. (2022-11-01). "Impact of the Jenkyns Event (early Toarcian) on dinosaurs: Comparison with the Triassic/Jurassic transition". Earth-Science Reviews. 234: 104196. Bibcode:2022ESRv..23404196R. doi:10.1016/j.earscirev.2022.104196. ISSN 0012-8252.
8. Molina-Pérez, Rubén; Larramendi, Asier; Atuchin, Andrey; Mazzei, Sante; Connolly, David; Cruz, Gonzalo Ángel Ramírez (2019). Dinosaur Facts and Figures: The Theropods and Other Dinosauriformes. Princeton University Press. ISBN 978-0-691-18031-1. JSTOR j.cdb2hnszb.