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Re: Sauropod Biology




Sim Koning wrote:

There were probably specialist sauropods such as Brachiosaurus and
Dicraeosaurus. With its high shoulders, Brachiosaurus was likely a high browser like giraffes and Indricotherium,
[snip]
As with all specialists, these forms were prone to extinction, which is probably why the Brachiosaurs died out not long after the Jurassic.

David's already mentioned _Sauroposeidon_ (Aptian), and there was also slightly earlier post-Jurassic forms like _Pelorosaurus_. Also, although the Brachiosauridae (sensu stricto) appears to have died out by the end of the Early Cretaceous, the titanosauriforms as a whole thrived in the Late Cretaceous. The 'brachiosaurs' of traditional usage comprise forms that we know recognize as basal titanosauriforms, including (but not limited to) true brachiosaurids (e.g., _Brachiosaurus_, _Sauroposeidon_, probably _Pelorosaurus_, _Atlasaurus_). Complicating things further is the fact that some titanosaurs ate grass (based on coprolite contents), which suggests they were low grazers - at least some of the time.


Well... *Sauroposeidon*, which was bigger rather than smaller than *Brachiosaurus*, is... how old? Aptian? That would be, like, 120 Ma... that's 25 Ma after the end of the Jurassic... Dicraeosaurids (*Amargasaurus*) and rebbachisaurids survived for a similar length of time.

Rebbachisaurids persisted into the Late Cretaceous. If the teeth named _"Titanosaurus" rahiolensis_ belong to a rebbachisaurid, then the group survived until close to the end of the Cretaceous period. (This is a big "if" though.)


Cheers

Tim