# Id this extinct South American hoofed critter **URL:** \ **Category:** Factual Questions\ **Created:** [May 5, 2009, 2:48pm UTC](https://boards.straightdope.com/t/id-this-extinct-south-american-hoofed-critter/495419 "2009-05-05T14:48:45Z")\ **Posts on this page:** 6\ **Page:** 2
**Author:** ![Earl\_Snake-Hips\_Tucker](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/earl_snake-hips_tucker/32/3269_2.png) [@Earl\_Snake-Hips\_Tucker](https://boards.straightdope.com/u/Earl_Snake-Hips_Tucker)\ **Post date:** [May 7, 2009, 4:17pm UTC](https://boards.straightdope.com/t/id-this-extinct-south-american-hoofed-critter/495419/21 "2009-05-07T16:17:48Z")
> [@Lemur866](#): > > Essentially, all of these groups were probably already distinct back in the Cretaceous, but gross morphologically they weren’t that different from each other–they were all little mousy-shrewy thingies. Some of those mousy-shrewies were the ancestors of artiodactyls, but the artiodactyl ancestors didn’t particularly look artiodactyly. And thanks for these comments. I hadn’t actually thought of itthat way, that the various mammal “lines” had already diverged in the Cretaceous, but, being that were still underfoot to the big lizards, that they weren’t nearly as morphologically dissimilar to each other as their descendants today, and in most cases not even remotely similar to their descendants. ---
**Author:** ![Darwins\_Finch](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/darwins_finch/32/20304_2.png) [@Darwins\_Finch](https://boards.straightdope.com/u/Darwins_Finch)\ **Post date:** [May 7, 2009, 5:12pm UTC](https://boards.straightdope.com/t/id-this-extinct-south-american-hoofed-critter/495419/22 "2009-05-07T17:12:59Z")
> [@Polycarp](#): > > Aside from the fact that stegosaurs survived in India well into the Cretaceous while going extinct everywhere else, I don’t know of any unique Indian forms. If you are referring to _Dravidosaurus_, the extremely fragmentary material upon which it was based was found to instead be a form of pliosaur, back in 1996. There are currently no definitively known Late Cretaceous stegosaurs. ---
**Author:** ![Lemur866](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lemur866/32/434_2.png) [@Lemur866](https://boards.straightdope.com/u/Lemur866)\ **Post date:** [May 7, 2009, 5:23pm UTC](https://boards.straightdope.com/t/id-this-extinct-south-american-hoofed-critter/495419/23 "2009-05-07T17:23:30Z")
> [@Darwins\_Finch](#): > > If you are referring to _Dravidosaurus_, the extremely fragmentary material upon which it was based was found to instead be a form of pliosaur, back in 1996. There are currently no definitively known Late Cretaceous stegosaurs. ☹ ---
**Author:** ![Polycarp](https://avatars.discourse-cdn.com/v4/letter/p/82dd89/32.png) [@Polycarp](https://boards.straightdope.com/u/Polycarp)\ **Post date:** [May 8, 2009, 12:21am UTC](https://boards.straightdope.com/t/id-this-extinct-south-american-hoofed-critter/495419/24 "2009-05-08T00:21:04Z")
> [@Darwins\_Finch](#): > > If you are referring to _Dravidosaurus_, the extremely fragmentary material upon which it was based was found to instead be a form of pliosaur, back in 1996. There are currently no definitively known Late Cretaceous stegosaurs. That’s exactly what I meant, and I’ve never seen any reports on this (not doubting your word of course; that’s a lot more my limited access to good palaeontological reports than anything else). Got a link, preferably not totally technical, I can look at? ---
**Author:** ![Darwins\_Finch](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/darwins_finch/32/20304_2.png) [@Darwins\_Finch](https://boards.straightdope.com/u/Darwins_Finch)\ **Post date:** [May 8, 2009, 12:53am UTC](https://boards.straightdope.com/t/id-this-extinct-south-american-hoofed-critter/495419/25 "2009-05-08T00:53:14Z")
There’s a lot of sketchy stuff on the interwebs (largely because the material itself is somewhat sketchy), but the following sites all seem to go for the “not a stegosaur” option: [Wikipedia link](http://en.wikipedia.org/wiki/Dravidosaurus) [Dinosaur Mailing List archive](http://dml.cmnh.org/1997Sep/msg00590.html) [The Plesiosaur Site](http://www.plesiosaur.com/database/genusIndividual.php?i=102) (little more than a blurb, but its presence on this site at all says something :p) [DinoData link](http://www.dinodata.org/index.php?option=com_content&task=view&id=6403&Itemid=67) In print, I checked my copy of _Dinosaurs: The Encyclopedia, Supplement 1_, and found the following as well: > [@](#): > > Regarding a taxon originally described as an Indian stegosaur, Chatterjee and Rudra (1996) visited the site (_Kossmaticeras theobaldianum_ Zone, Trichinopoly Group) which yielded the only remains thus far collected of _Dravidosaurus blandordi_, there finding only fragmentary material belonging to plesiosaurs. Reexamining the holotype (GSI SR PAL 1, a fragmentary skeleton) of this type species, Chatterjee and Rundra found nothing pertaining to the supposed stegosaurian plates and skull as claimed by the species’ authors, Yadagiri and Ayysami (1979). Instead, they found “highly weathered limb and girdle elements that may belong to plesiosaurs.” At this point, then, the remains and locale seem to indicate “plesiosaur” rather than “stegosaur” (or pliosaur, for that matter…my oops), though nothing is necessarily definitive at this point. The best one can really say is that _Dravidosaurus_ is currently a _nomen dubium_, and the fossils may or may not be a plesiosaur, and that the notable stegosaurian traits (plates + skull) seem to be absent. Since Chatterjee and Rudna are the most recent to publish anything on the specimen, their papers (see the DML archive link above for the actual references) represent the current status of the beastie. ---
**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\ **Post date:** [May 8, 2009, 4:18am UTC](https://boards.straightdope.com/t/id-this-extinct-south-american-hoofed-critter/495419/26 "2009-05-08T04:18:21Z")
> [@Lemur866](#): > > It’s just that South American mammals are such a striking example of convergency. They’ve got convergent evolution for everything, even for stuff we don’t have anymore. Australia’s marsupials are a very distant second place. I’m currently working on an exhibition on the Great American Biotic Interchange, which will also feature some examples of convergence. We’ll be comparing fossils of rhinos and toxodonts, horses and [Thoatherium](http://scienceblogs.com/laelaps/thoatheriumknight.jpg), and [Smilodon](http://laelaps.files.wordpress.com/2007/10/smildonknight.jpeg) and [Thylacosmilus](http://www.geol.umd.edu/~jmerck/bsci392/lecture40/thylacosmiluss.jpg). > [@](#): > > I never hear anything about weird Indian fossils, yet India was also an island continent for something like 40 million years. Some recent controversial evidence suggests that the [condylarth](http://news.nationalgeographic.com/news/2007/11/071108-india-mammal.html) ancestral ungulates could have originated in India. [Previous page](https://boards.straightdope.com/t/id-this-extinct-south-american-hoofed-critter/495419.md?page=1)