| Choconsaurus | |
|---|---|
Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Reptilia |
| Clade: | Dinosauria |
| Clade: | Saurischia |
| Clade: | †Sauropodomorpha |
| Clade: | †Sauropoda |
| Clade: | †Macronaria |
| Clade: | †Titanosauria |
| Genus: | †Choconsaurus Simón et al.2017 |
| Type species | |
| †Choconsaurus baileywillisi Simón et al. 2017 | |
Choconsaurus ("El Chocón lizard") is an extinctgenus of herbivoroussauropoddinosaur belonging to the groupTitanosauriformes, which lived in the area of present-dayArgentina at the end of theCretaceous.[1]
Theholotype (specimen MMCh-PV 44/10) was found inVilla El Chocón inNeuquén province,Argentina by Viviana Moro before 1996.[1]
Subsequent field campaigns carried out at Manuel Bustingorry's "Bustingorry II" site by theErnesto Bachmann Paleontological Museum and theMuseum of Geology and Paleontology of the National University of Comahue between 1996 and 2002 discovered more remains pertaining toChoconsaurus, with several of the specimens described byCalvo (1999) under "Titanosauridae indet.";[2] these field campaigns also recovered the holotype ofBustingorrytitan.[3]
In 2017, the species typeChoconsaurus baileywillisi was named and described by Edith Simón, Leonardo Salgado and Jorge Orlando Calvo. The genus name refers to its discovery in El Chocón. For its part, the name of the species is in homage to the American geologistBailey Willis, who traced thestratigraphy of the area between 1910 and 1914.[1]
Theholotype specimen was found in a layer of theHuincul Formation dating to the end of theCenomanian epoch. It consists of a partial skeleton lacking a skull. The vertebrae of the neck, back and tail and parts of the limbs were preserved. This constitutes the most complete skeleton known of a basal titanosaur in 2017.[1]
The describing authors have identified some distinctive features. In thecervical vertebrae, the upper edge of the face of the posterior joint was hardly developed. In the first vertebrae there are very large secondary protuberances on both sides of the hyposphene. The central and posterior vertebrae have an additional crest located between the posterior crest that extends from the lateral protrusion to the vertebral body and the secondary crest running parallel to the main crest. The frontal vertebrae of the tail have a protrusion in the posterior hyposphenic secondary joint.[1]
Choconsaurus was classified in its description article of 2017 within thecladeTitanosauria in abasal position, outside the cladeEutitanosauria.[1]
