MEANING: Salt giant
PERIOD: Late Cretaceous
CONTINENT: South America
Chadititan is a titanosaurian sauropod dinosaur from the Late Cretaceous of what is now Argentina. It was a relatively small sauropod at about 7 m in length. While it had the typical sauropod body plan with the long neck and tail, Chadititan was relatively slender, and had more gracile limbs. It is also notable that no specimens show signs of osteoderms.
Abstract from paper: Here we describe a new fossil invertebrate and vertebrate assemblage from a previously unknown locality of the Anacleto Formation (Campanian, Upper Cretaceous), near General Roca city, Río Negro Province, Argentina. The specimens were found in a single fossiliferous layer, which yielded bivalves and gastropods, including the first fossil record of the terrestrial clade Megalomastomatidae and the first undoubted record for the terrestrial subulinid Leptinaria. Vertebrates are represented by fishes (lepisosteids, percomorphs, and the dipnoan Metaceratodus kaopen), chelid turtles, a single crocodyliform scute, an indeterminate pterosaur, an incomplete meridiolestidan mammalian jaw, and abelisaurid and rinconsaurian titanosaur dinosaurs. The latter is represented by several individuals of a small and gracile-limbed form. The phylogenetic analysis recovers a monophyletic Rinconsauria including the new taxon, plus Rinconsaurus, Pitekunsaurus, Overosaurus, and Muyelensaurus. The new titanosaur indicates that rinconsaurians were characterized by a body shape that was different from other titanosaurs, with brachiosaur-like posture, gracile limbs, and protonic tail. The faunistic assemblage is characterized by the abundance, but low diversity, of chelid turtles and a very low number of crocodyliforms. This taxonomic composition is reminiscent of other faunal assemblages of the latest Cretaceous of northern Patagonia, but differs markedly from Campanian assemblages known from North America and Europe.
Chadititan is from the Cretaceous. The Cretaceous is a geological period that lasted from about 145 to 66 million years ago. It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of the entire Phanerozoic. The name is derived from the Latin creta, "chalk", which is abundant in the latter half of the period.
The Cretaceous was a period with a relatively warm climate, resulting in high eustatic sea levels that created numerous shallow inland seas. These oceans and seas were populated with now-extinct flora and fauna, while dinosaurs continued to dominate on land. The world was ice free, and forests extended to the poles. During this time, new groups of mammals and birds appeared. During the Early Cretaceous, flowering plants appeared and began to rapidly diversify, becoming the dominant group of plants across the Earth by the end of the Cretaceous, coincident with the decline and extinction of previously widespread gymnosperm groups.
The Cretaceous (along with the Mesozoic) ended with the Cretaceous–Paleogene extinction event, a large mass extinction in which many groups, including non-avian dinosaurs, pterosaurs, and large marine reptiles, died out. The end of the Cretaceous is defined by the abrupt Cretaceous–Paleogene boundary (K–Pg boundary), a geologic signature associated with the mass extinction that lies between the Mesozoic and Cenozoic Eras.
Chadititan is a sauropod. Sauropods are saurischian dinosaurs that had very long necks, long tails, small heads (relative to the rest of their body), and four thick, pillar-like legs. They are notable for the enormous sizes attained by some species, and the group includes the largest animals to have ever lived on land. Well-known genera include Brachiosaurus, Diplodocus, Apatosaurus and Brontosaurus.
The oldest known unequivocal sauropod dinosaurs are known from the Early Jurassic, and by the Late Jurassic (150 million years ago), sauropods had become widespread. By the Late Cretaceous, one group of sauropods, the titanosaurs, had replaced all others and had a near-global distribution. This group included the largest animals ever to walk the earth. Estimates vary, but the largest titanosaurs are estimated at upward of around 40 m, and weighing 100 t, or possibly even more.
As with all other non-avian dinosaurs alive at the time, the titanosaurs died out in the Cretaceous–Paleogene extinction event. Fossilized remains of sauropods have been found on every continent, including Antarctica.