Orthogoniosaurus

Orthogoniosaurus
Temporal range: Late Cretaceous, 66 Ma
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Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Clade: Dinosauria
Clade: Saurischia
Clade: Theropoda
Genus: †Orthogoniosaurus
Das-Gupta, 1931
Species:
†O. matleyi
Binomial name
†Orthogoniosaurus matleyi
Das-Gupta, 1931
Other species
Synonyms
  • "Massospondylus" rawesi? Lydekker, 1890

Orthogoniosaurus (meaning "straight angled lizard", referring to the straight posterior edge of its type tooth) is a dubious genus of theropod dinosaur from the late Maastrichtian-age Upper Cretaceous Lameta Formation of Jabalpur, India. It is based on one small, fragmentary tooth (preserved section 27 mm (1.1 in) long).[1]

Because it is the earliest published name for a Lameta theropod, it has sometimes been used as a synonym for other contemporaneous theropods, such as Indosaurus and Indosuchus.[2] As a tooth taxon, however, such usage has been discouraged.[3] Ralph Molnar in 1990 noted that the form of the tooth was most like teeth from the rear of theropod jaws, although the lack of serrations on the leading edge was unusual.[4] In 2004 it was considered to be a dubious ceratosaurian.[5] Later studies have considered it to be a abelisaurid.[6][7]

"Massospondylus rawesi", another tooth taxon,[8] is sometimes given as a second species. It was suggested that the tooth may not be dinosaurian, and could be substantially older.[9] However more recent research agrees on a cretaceous age and likely pertain to a theropod,[6] possibly an abelisaurid.[7]

  1. ^ Das-Gupta, H.C. (1931). On a new theropod dinosaur (Orthogoniosaurus matleyi, n. gen. et n. sp.) from the Lameta beds of Jubbulpore. Journal of the Asiatic Society of Bengal, New Series 16(20):367-369.
  2. ^ Romer, A.S. (1956). Osteology of the Reptiles. University of Chicago Press:Chicago 1-772. ISBN 0-89464-985-X
  3. ^ Walker, A.D. (1964). Triassic reptiles from the Elgin area: Ornithosuchus and the origin of carnosaurs. Philosophical Transactions of the Royal Society of London, Series B 248(744):53-134.
  4. ^ Molnar, R.E. (1990). Problematic Theropoda: "Carnosaurs". In: Weishampel, D.B., Dodson, P., and Osmólska, H. (eds.). The Dinosauria. Berkeley and Los Angeles: University of California Press:Berkeley and Los Angeles, p. 306-317. ISBN 0-520-06727-4
  5. ^ Tykoski, R.S., and Rowe, T. (2004). Ceratosauria. In: Weishampel, D.B., Dodson, P., and Osmolska, H. (eds.). The Dinosauria (second edition). University of California Press:Berkeley, 47-70. ISBN 0-520-24209-2
  6. ^ a b https://www.researchgate.net/publication/230808666_The_history_of_dinosaur_collecting_in_Central_India_1828-1947 [bare URL]
  7. ^ a b 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.
  8. ^ Lydekker, R. (1890). Note on certain vertebrate remains from the Nagpur District. Records of the Geological Survey of India 23:20-24.
  9. ^ Peter Galton quoted in: Glut, D.F. (1997). Dinosaurs: The Encyclopedia. McFarland & Company:Jefferson, North Carolina, p. 654. ISBN 0-89950-917-7.