Narindasaurus

Narindasaurus Temporal range: Middle Jurassic, ~168–165  Ma PreꞒ Ꞓ O S D C P T J K Pg N ↓
Left pubis (MNHN MAJ 430)
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Reptilia
Clade:	Dinosauria
Clade:	Saurischia
Clade:	† Sauropodomorpha
Clade:	† Sauropoda
Clade:	† Turiasauria
Genus:	† Narindasaurus Royo-Torres et al., 2020
Species:	†N. thevenini
Binomial name
†Narindasaurus thevenini Royo-Torres et al., 2020

Narindasaurus (meaning "Narinda Bay lizard") is a genus of turiasaurian sauropod dinosaur from the Middle Jurassic Isalo III Formation of Madagascar. The type and only species is Narindasaurus thevenini. The only known specimen of the genus was first described in 1907, but it was not formally named as a distinct species until 2020.

Discovery and naming

Sauropod specimens were collected from various sites in Madagascar for the Muséum d'Histoire Naturelle de Paris between 1896 and 1905. ^[1] They were briefly noted on by Paul Lemoine in 1906. ^[2] In 1907, Armand Thevenin described the specimen that would later become the holotype of Narindasaurus thevenini as belonging to the species Bothriospondylus madagascariensis . ^[3] It was briefly mentioned in 1972. ^[4] In 1986, José Bonaparte considered the specimens described by Thevenin to belong to the species Lapparentosaurus madagascariensis . ^[5] It was reevaluated in 2008 and 2010 as both a distinct taxon and a non-neosauropod eusauropod. ^{[6] [1]} Its teeth were noted as being characteristic of turiasaurs in 2015. ^[7] The genus and species Narindasaurus thevenini were named in 2020 by Rafael Royo-Torres and colleagues, and it was demonstrated to be a turiasaur by phylogenetic analysis. The genus name refers to Narinda Bay, which is near the type locality of the species, and the species name honors Thevenin. ^[8]

Fossil record

The holotype and only known specimen of Narindasaurus thevenini is a partial skeleton recovered from the Isalo III Formation of Madagascar. The specimen, which is housed at the Muséum national d’Histoire naturelle, is composed of a right maxillary or premaxillary tooth (MNHN MAJ 423), an anterior caudal vertebra (MNHN MAJ 424), a posterior caudal vertebra (MNHN MAJ 426), a middle-anterior chevron (MNHN MAJ 425), a right ulna (MNHN MAJ 427), a right tibia (MNHN MAJ 428), a right fibula with a distal chevron attached (MNHN MAJ 429) and a left pubis (MNHN MAJ 430). ^[8]

Description

The teeth show the heart-shaped morphology typical of turiasaurs. ^{[7] [8]} The caudal vertebrae from the middle-anterior region of the tail show an asymmetric lateral fossa that is placed in a posterior position, uniquely to the genus. ^[8]

References

1. Mannion, Philip D. (2010). "A revision of the sauropod dinosaur genus Bothriospondylus with a redescription of the type material of the Middle Jurassic form B. madagascariensis". Palaeontology. 53 (2): 277–296. doi:10.1111/j.1475-4983.2009.00919.x. ISSN   0031-0239..
2. Lemoine P. 1906. Études géologiques dans le nord de Madagascar. In: Herman A, ed. Contributions à l’histoire géologique de l’Océan Indien. Paris: Librairie Scientifique, 1–520.
3. Thevenin A. 1907. Paléontologie de Madagascar. IV Dinosauriens. Annales de Paléontologie 2: 121–136.
4. Besairie H, Collignon M. 1972. Géologie de Madagascar, 1. Les terrains sédimentaires. Annales Géologiques de Madagascar 35: 1–463.
5. Bonaparte, José F. (1986). "The early radiation and phylogenetic relationships of the Jurassic sauropod dinosaurs, based on vertebral anatomy". In Padian, Kevin (ed.). The beginning of the age of dinosaurs: faunal change across the Triassic–Jurassic boundary. Cambridge: Cambridge University Press. pp. 247–258. ISBN   0-521-30328-1.
6. Läng E. 2008. Les cétiosaures (Dinosauria, Sauropoda) et les sauropodes du Jurassique moyen: révision systématique, nouvelles découvertes et implications phylogénetiques. Unpublished Ph.D Thesis, Muséum national d’Histoire naturelle, Paris.
7. Mocho, Pedro; Royo-Torres, Rafael; Malafaia, Elisabete; Escaso, Fernando; Silva, Bruno; Ortega, Francisco (2015-06-19). "Turiasauria-like teeth from the Upper Jurassic of the Lusitanian Basin, Portugal" . Historical Biology. 28 (7): 861–880. Bibcode:2016HBio...28..861M. doi:10.1080/08912963.2015.1049948. ISSN   0891-2963. S2CID   129076933.
8. Rafael Royo-Torres; Alberto Cobos; Pedro Mocho; Luis Alcalá (2020). "Origin and evolution of turiasaur dinosaurs set by means of a new 'rosetta' specimen from Spain". Zoological Journal of the Linnean Society. 191: 201–227. doi: 10.1093/zoolinnean/zlaa091 .