Coastal Laramidia ( Late Cretaceous).  A couple of T. exes are feasting from a “Sabinosaurio” carcass, while several azdharxhids queue for their turn… Impossible? Not according to Dr.  Claudia Serrano Brañas  that after reading my comments in the previous blog about Totlmimus, through personal communication, graciously gave me this link and comments as  information.

Tyrannosaurid teeth from the Lomas Coloradas Formation, Cabullona Group (Upper Cretaceous) Sonora, México

“Regarding the comment of the tyrannosaurids that were present in the Cabullona Basin of Sonora, my colleagues and I published a paper in 2014 concerning the identification of Tyrannosaurus rex in the Lomas Coloradas Formation, which is the top formation of the Cabullona Group.”

“With regard to the information you request, I leave you with the following comments: When working with isolated teeth, great care must be taken when assigning them to a particular family or genre, as there is a great morphological similarity between many groups Of theropods. In the case of tyrannosaurids, this happens frequently, since their teeth are very similar to each other. For this reason, in addition to the anatomical descriptions of the specimens, different types of statistical analyses using quantitative parameters have now begun to be used in order to discriminate between taxa so that the specimens can be assigned to a group or genus of theropods in particular. In our case, we measured our specimens and compared them with a database that included 342 teeth of different types of theropods and precisely through the analysis of the combination of these variables, we were able to establish that our specimens corresponded to the genus Tyrannosaurus.
On the other hand, I wanted to point out that we are currently working with other teeth of the Cabullona Basin in Sonora, but this time they are from another formation of the same Geological Group (Cabullona Group). These new teeth, although also of tyrannosaurids, are very different from those found in the Lomas Coloradas formation, which would indicate that in addition to having Tyrannosaurus in that area, there were also other types of tyrannosaurids. As soon as I get more information about it, I’ll let you know.”

 So there you have it: Although the remains (mainly  teeth) come undoubtedly from tyrannosaurids, some are diagnostic of T. rex… although there might be some doubters (ready for it Dave Hone?)! It makes complete sense to locate Tyrannosaurus rex in Mexico too. It shared the same environment as the “Sainosaurio” and Tototlmimus.

So understanding that most, if not all of you, need something to cheer you up for having to turn off your TV today (and avoid a really bad remake of the Twilight Zone),  here’s something factual for your solace from this  Blog. An entertaining  beginning of the year no doubt.