| Chucarosaurus | |
|---|---|
 | |
| Skeletal diagram ofChucarosaurus | |
Scientific classification | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Clade: | Dinosauria |
| Clade: | Saurischia |
| Clade: | †Sauropodomorpha |
| Clade: | †Sauropoda |
| Clade: | †Macronaria |
| Clade: | †Titanosauria |
| Clade: | †Colossosauria |
| Genus: | †Chucarosaurus Agnolinet al.,2023 |
| Species: | †C. diripienda |
| Binomial name | |
| †Chucarosaurus diripienda Agnolinet al., 2023 | |
Chucarosaurus (meaning "indomitable reptile") is anextinct genus oftitanosauriandinosaur from theLate Cretaceous (middleCenomanian–lowerTuronian)Huincul Formation ofArgentina. The genus contains asingle species,C. diripienda, known from various limb and pelvic bones.[1]
TheChucarosaurusholotype specimen, MPCA PV 820, was discovered in sediments of theHuincul Formation, dated to the middleCenomanian–lowerTuronian ages of the lateCretaceous period, atPueblo Blanco Natural Reserve inRío Negro Province, Argentina. The specimen consists of a complete lefthumerus, partial leftradius, complete leftmetacarpal II, leftischium, partial leftfemur andfibula, partial righttibia, and partial indeterminatemetapodial, all of which belong to one individual. An additional specimen (MPCA PV 821), consisting of a left femur and tibia, was assigned as theparatype.[1]
In 2023, Agnolinet al.describedChucarosaurus diripienda, a new genus and species of colossosaurian titanosaurs, based on these fossil remains. Thegeneric name, "Chucarosaurus", combines "chucaro", aQuechua word meaning "hard and indomitable animal" with theLatin word "saurus", meaning "reptile". Thespecific name, "diripienda", is derived from a Latin word meaning "scrambled".[1]
Chucarosaurus was a large, slender-limbed titanosaur. Itsfemur was roughly 1.9 metres (6.2 ft) long, somewhat smaller than the estimated 2.5 metres (8.2 ft) length of the femur ofArgentinosaurus. The forelimb was shorter than the hindlimb, with a humerus 78% the length of the femur, as is typical of titanosaurs but unlike some basal titanosauriforms such asbrachiosaurids. As in other colossosaurs, the deltopectoral crest of the humerus was thickened in its distal half. Theischium has a shorter, more robust iliac peduncle than in other titanosaurs.[1]
Agnolinet al. (2023) recoveredChucarosaurus as acolossosaurian member of the Titanosauria, as thesister taxon to a clade formed byNotocolossus and theLognkosauria. The results of theirphylogenetic analyses are shown in thecladogram below:[1]
Chucarosaurus is known from the Late Cretaceous Huincul Formation of Río Negro Province, Argentina. Many dinosaurs, including fellow titanosaurs (ArgentinosaurusBustingorrytitan, andChoconsaurus),[2] rebbachisaurids (Cathartesaura,Limaysaurus, andSidersaura),[3][4] carcharodontosaurids (Mapusaurus,Meraxes, andTaurovenator),[5] a megaraptoran (Aoniraptor), abelisaurids (Skorpiovenator,Tralkasaurus, andIlokelesia), an elaphrosaurine (Huinculsaurus),[6] a paravian (Overoraptor), and the unusual avetheropodGualicho have also been named from the formation.[7][8] Remains ofunenlagiids,iguanodonts, andelasmarian ornithopods are also known.[1]
