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Remember the Alamosaurus (was RE: taxonomy is not stratigraphy)

(Posted for Jon Wagner, who is currently not subscribed.)
As possibly the only person participating in this discussion to have seen the relevant material (apart from Ken Carpenter), and almost certainly the only one to have WORKED in the Javelina Formation, I'd like to make a few points. Funny, it seems I have to e-mail the list once a year to make these points, every time a new tyrannosaur paper comes out...

1) Alamosaurus certainly HAS been used as a taxonomic "wastebasket," but there are reasons to believe that many, if not most of the referred specimens belong to a single clade of sauropods. Thus, not all cited occurrences of Alamosaurus may be A. sanjuanensis, but this doesn't mean the whole taxon is kaput. See Lehman and Coulson (2002).

2) The "Javelina tyrannosaur" is either a) indeterminate (i.e., cannot be called T. rex), or b) a new species and definitely not T-rex. Ron Tykoski and I are working (long term) on a redescription of the maxilla of this animal; whether or not it is a new taxon depends a bit on the patterns of variation in tyrannosaurids (believe it or not, the variation in question has not yet been documented fully, despite Carr's impressive body of work). Oddly enough, when viewed in life position (Lawson illustrates it laid flat), this maxilla is not as short as it first appears, and the animal was probably within the range in snout shape seen in T. rex. It is not at all clear whether the maxilla is from an adult, so claims that it is an undersized tyrannosaurid are premature (it is larger than "Nannotyrannus," based on published illustrations). I believe we will be able to say it is indeed a new species, and, given its apparent phylogenetic position, possibly a new genus. We aren't likely to name it, though, since the material is so fragmentary.

3) There is no evidence from the Javelina Formation that tyrannosaurids fed on sauropods. There are many tooth-marked bones from this unit, none are sauropod (and sauropod bones are very common) (Lehman, pers. com., 2005).

4) One abstract with one date from the MIDDLE of a unit must NOT be used to date an entire formation. The Javelina grades into the overlying Black Peaks Formation, and the K/T boundary "wobbles" between these two units. There is no evidence that I know of for a hiatus between the two units, nor a hiatus at the boundary. In fact, the K/T boundary IS preserved in some sections. I have eaten lunch on it. Additional radiometric data have not yet been released. Without spoiling the "surprise," I'll just say that I have every confidence that the Javelina is, at least in part, contemporaneous with the Lance, given what is currently known.

5) To respond to something Denver Fowler wrote:
Lehman got his stratigraphy
confused (see various works by Sullivan et al);

Denver, with all due respect, I think you ought to pick your stratigraphers a little more carefully. If you get out in the field and try to reproduce results, I believe you will find that you are backing the wrong horse. Recall that "Sullivan et al." includes the folks who named Naashoibitosaurus, which isn't even from the Naashoibito. Lehman informed me of this years before it hit the press, because he REMEMBERED, off the cuff, where that site is. You have every right to follow whatever authority you see fit, but I respectfully recommend you do so based on something other than the date of publication.

If you wish to reply to this message, please reply to me as well, as I am not on the list, and be prepared to forward my replies as well.