Isolated Teeth

[megabass22]

I have a herbivore dinosaur tooth in my collection identified as Triceratops horridus, this is a quite common type of tooth and is almost always identified as such. But looking at the dinosaurs of Hell Creek (where the tooth is from) couldn´t it equally well be a Triceratops prorsus tooth, a Torosaurus tooth or even a Tatankaceratops tooth? Are there any particular morphological things unique to Triceratops or are these teeth just sold as "Triceratops horridus" since that is easier to sell than "Chasmosaurinae indet."? Wouldn´t i be equally confident if i labelled it as Torosaurus?

Of course with some teeth it´s easier, for an example, only Spinosaurus teeth actually look like Spinosaurus teeth and so on, but with small herbivore teeth how easy is it to determine species?

[Troodon]

I'm not aware of differences in teeth between Triceratops or Torosaurus species but they may exist. In my collection they are labeled "Triceratops sp." because I'm not sure Torosaurus is a valid species but that debate is still underway. However you are correct the more accurate call would be Chasmosaurinae indet. and yes its a much harder sell with that ID. Most collectors and dealers know what a Triceratops is but Chasmosaurinae what's that? Also, its my belief is that collectors like to purchase specific species and not something that is unclear so its a good marketing practice. I'm not that familiar with Tatankaceratops teeth other than saying its a smaller animal so that an adult Trike tooth would be too big. Next time I see Pete Larson I will ask him since he helped describe it.

[megabass22]

No one is familiar with Tatankaceratops teeth, as none are known to have been found :

Though one could presume that they were quite similar to Triceratops.

[Troodon]

Thanks, yep no teeth were found. Well this is a one species that some consider questionable. More complete specimens will need to be found to silence the naysayers.

[painshill]

Thanks, yep no teeth were found. Well this is a one species that some consider questionable. More complete specimens will need to be found to silence the naysayers.

It’s not quite true to say that there were no teeth. Ott and Larson reported “several dozen dentary teeth are present and are of typical ceratopsid morphology.” There were however no identifiable maxillaries.

Thomas Holtz Jr. and others have suggested that Tatankaceratops is simply a juvenile Triceratops, but it has a strange mix of characteristics already known from adult and juvenile Triceratops. Nicholas Longrich in “Titanoceratops ouranos, a giant horned dinosaur from the Late Campanian of New Mexico” [Cretaceous Research, 2011] suggested that the Tatankaceratops might represent a dwarf Triceratops species or a Triceratops individual with a developmental growth disorder.

Darren Naish, in his 2012 review of “New perspectives on horned dinosaurs: the Royal Tyrrell Museum Ceratopsian Symposium” (Michael J. Ryan, Brenda J. Chinnery-Allgeier and David A. Eberth) also commented on Tatankaceratops sacrisonorum as follows: “The existence of a new chasmosaurine in the late Maastrichtian of western North America is interesting in view of debates about dinosaur diversity at this time and place, and it is inevitable that some will immediately identify the type and only specimen as a juvenile Triceratops (as anyone interested in dinosaurs will know all too well, debate continues as to whether some or all late Maastrichtian chasmosaurines represent distinct taxa, or growth stages of the same species). However, Tatankaceratops has proportionally short, subvertical postorbital horns that look different from both the far longer, posteriorly curving horns present in juvenile Triceratops and the even longer, anteriorly curving horns present in adult Triceratops (Horner and Goodwin 2006). The possibility that it might represent a dwarf form of Triceratops (Longrich 2011) appears plausible, as does the suggestion that it could be an aberrant individual.”

Edited August 6, 2014 by painshill