Saltasaurinae

Saltasaurinae is a subfamily of titanosaurian sauropods known from the late Cretaceous period of South America, India and Madagascar.

Description

Saltasaurines are relatively small sauropods with the general body shape of a small head, long neck, four limbs, and a long tail. They range from the small '' Ibirania'' at around , to the larger ''Neuquensaurus'' at . A currently unnamed fragmentary sauropod from Madagascar may turn out to be a saltasaurine longer than ''Neuquensaurus''. The weight of saltasaurines is very light compared to that of some of the largest dinosaurs. Thomas R. Holtz Jr. found the genera range from around , with ''Saltasaurus'' and an unnamed genus on both extremes, respectively.Holtz, Thomas R. Jr. (2011) ''Dinosaurs: The Most Complete, Up-to-date Encyclopedia for Dinosaur Lovers of All Ages,'
Winter 2010 Appendix.
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Saltasaurinae is the only known group of sauropods found with armour from almost every species. The most probable reason for the bony studs and plates is that it evolved for defence against theropods like '' Abelisaurus'' and ''Carnotaurus''. Saltasaurine armour has led to controversies; in 1929, the paleontologist Friedrich von Huene named the genus ''Loricosaurus'' for armour he thought to be from ankylosaurians. These bones were found to have similarities to those later discovered on sauropods like ''Saltasaurus'' and ''Neuquensaurus'', and as such, ''Loricosaurus'' may be the same as one of the other genera.

Age and distribution

Saltasaurines lived in the late Cretaceous, from the early Campanian to the Maastrichtian (about 80–66 million years ago) when they went extinct along with all other non-avian dinosaurs. ''Saltasaurus'' is the only named Saltasaurine that lived later in the Maastrichtian than 68 million years ago. ''Loricosaurus'' and ''Neuquensaurus'' lived around 71 million years ago and the later surviving ''Jainosaurus'' lived around 68 million years ago. An unnamed Saltasaurine from Madagascar would have probably survived later, until the Cretaceous-Paleogene extinction event, around 66 million years ago.

The subfamily Saltasaurinae is known almost completely from the Southern Hemisphere with South American forms. ''Jainosaurus'' and '' Abditosaurus'' are two of the only definite saltasaurines from outside the Southern Hemisphere and is two of the only ones from outside of South America.

Classification

In a 1992 study on ''Saltasaurus'', Jaime Powell named Saltasaurinae, a new subfamily within Titanosauridae (a family now considered invalid). He found many features uniting the group, consisting of the type genus and ''Neuquensaurus''. This group was later supported and defined by Salgado ''et al.'' (1997). They defined the subfamily as "the clade including the most recent common ancestor of ''Neuquensaurus australis'', ''Saltasaurus loricatus'', and all of its descendants". They conducted a phylogeny and found that the subfamily was sister to '' Alamosaurus'' and only included ''Neuquensaurus'' and ''Saltasaurus''. Paul Sereno defined it in 1998, unaware of Salgado's work and gave it a new definition as a stem clade. His definition was "All saltasaurids more closely related to ''Saltasaurus'' than to ''Opisthocoelicaudia''". In 2003, Jeffrey A. Wilson and Paul Upchurch elaborated on this definition to "all Saltasauridae more closely related to ''Saltasaurus loricatus'' than to ''Opisthocoelicaudia skaryzinskii''".

Below is a cladogram by Villa ''et al.'' (2022), from the description of the European saltasaurine '' Abditosaurus''.

References

{{Taxonbar, from=Q2535065

Cretaceous dinosaurs
Saltasaurids