[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

Re: Pleurocoelus in Texas (and Arkansas)




Steve Brusatte asked,

"Does anybody know who found the first bones of Pleurocoelus in Texas, and
where the discovery was located?  Also, what material is known from Texas?
Finally, what supposed Pleurocoelus tracks are known from outside of
Dinosaur Valley State Park?"

    The whole Pleurocoelus picture is nothing but confusing!

    Neither Glut's DINOSAURS The Encyclopedia nor THE DINOSAURIA clarify who
found the first Pleurocoelus bones in Texas, and the Pleurocoelus situation
is made even more confusing with the NMNH (Smithsonian) treating material
sometimes attributed to Astrodon johnstoni as being of Pleurocoelus, with
Astrodon being regarded as a junior synonym of Pleurocoelus.

    As to the Texas part, last month Dr. Wann Langston of the University of
Texas showed me through the entire vertebrate paleontology lab and storage
fascility at the U.T.'s J.J. Pickle Research Center in Austin.  There,
Langston showed me a beautiful, gigantic, and complete femur which he said
was of Pleurocoelus and that it was found "very near" the famous Brontopodus
birdi (inchospecies) track site in the Paluxy River bed near Glenn Rose.
Although I did not ask him who found it or specifically when, I seem to
recall that something he said made me think the great femur was a somewhat
recent find.

    I'm glad you asked what "supposed" Pleurocoelus tracks are known from
outside Dinosaur Valley State Park, because pinning a specific trackmaker
identity on sauropod tracks can be pretty tricky if not impossible.
However, there are some sites other than Glen Rose which I will mention
(there are others, also) that might be attributed somewhat reasonably to
Pleurocoelus:  The Medina River (Mayan Ranch in Bandera County) "swimming
sauropod" site; the West Verde Creek site (Davenport Ranch, Medina County),
which is in the upper member of the Glen Rose Limestone; and there are also
sauropod tracks in Sidney (Twin Mountain Formation, Comanche County); the
Blanco River site (Lower Glen Rose Limestone, Blanco County); the Briar site
(De Queen Formation, equivalent of the middle of the Glen Rose Limestone, in
Howard County, Arkansas); the Miller Creek site (in the middle of the Glen
Rose Limestone and close to the Corbura bed, Blanco County, Texas), and the
South San Gabriel River site (Upper Glen Rose Limestone, Williamson County,
Texas).  This is not an exhaustive list.

    A single supposed sauropod track (quite non-diagnostic in its ambiquity)
is (or was) located at the Zilker Garden multi-trackway 'old quarry' site
(tri-dactyl tracks) just south of the town lake in Austin (Travis County,
Texas, with the site in process of being modified for a 'prehistoric
park' -- whatever that means).

    Also, several years ago I found an incredible hatchling sauropod
trackway in Travis County.  It is in my private collection and will be
included in my photo illustrated book of actual baby dinosaur tracks
entitled TRACKING BABY DINOSAURS, in preparation.  (Does anyone know a good
prospective publisher?)  This remarkably diminutive trackway was described
and illustrated in one of my Dinofest '98 talks in Philadelphia. The tiny
sauropod tracks are perfect, 'textbook' Brontopodus birdi (the pes claws may
be relatively longer than those made by adult Pleurocoelus, and probably
were handy in escaping the egg shell shortly before the tracks were made),
but the pes length is only 6.0 cm and the manus is only 2.8 cm across!

    My personal opinion is that Pleurocoelus and Astrodon are NOT
synonymous, and I seem to recall some recent bone studies suggesting that,
but do not remember the reference off the top of my head.  Also, some
differences in the Maryland Early Cretaceous sauropod tracks I have found,
might be taken to mean that at least some of them were make by a track maker
somewhat different than the Glen Rose sauropod.  The superficial observer
might readily assign them to Brontopodus birdi, but I'm not so sure.

    There are various sauropod track sites around the world, but I would
hesitate to unequivocally assign any others to Brontopodus birdi, despite
the substantial similarities that exist in some of them.

    The most important reference in this context is the really superb paper
entitled Brontopodus birdi, Lower Cretaceour Sauropod Footprints from the
U.S. Gulf Coastal Plain, by our own list member James O. Farlow, with
Jeffrey Pittman, and J. Michael Hawthorne, which appears in Dinosaur Tracks
and Traces, edited by David D. Gillette and Martin G. Lockley, Cambridge
University Press, 1989, ISBN 0-521-36354-3 hardback and ISBN 0-521-40788-5
paperback.

    I hope this is of some help.

    Ray Stanford
    College Park, MD

"You know my method.  It is founded upon the observance of trifles." --
Sherlock Holmes in The Boscombe Valley Mystery