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N. AMERICAN SPINOSAURS
It is an amazing 'coincidence' that _Lepidotes_ and its relatives
(the semionotids) became extinct at the same time as spinosauroids,
as we now know thanks to Eaton et al. (1997). Once again I am
reminded of that quote in Grande and Beamis (1998) about *patterns in
nature* demanding explanations.
Thomas Holtz wrote..
> I'm willing to bet that _Baryonyx_ or related spinosaurid will show
> up in the Lakota Fm. or Yellow Cat Member of the Cedar Mountain Fm.
> or similar aged unit from western North America. Some of the same
> herbivorous dinosaurs are there as in the Wessex & Vectis Fms.
> (upper Wealden), some of the same fish, so I wouldn't be surprised
> if some of the same carnivores were as well.
Jim Kirkland then confirmed that he thinks much the same: Jim, has
this been published? I'd like a ref if possible (as you'd guess, this
is all very important to those of us working on the Wealden
theropods). Anyway, I'm real pleased to hear you guys say this, as I
have made the same suggestion, and have sort of gotten it in print
(in an abstract). The ref for this is:-
NAISH, D. 1998. Predatory dinosaurs in England's Lower Cretaceous:
crocodile heads, puffin snouts and the odd Lazarus taxon. IN ANON.
_Cretaceous Biodiversity, Programme and Abstracts to 1998 Summer
Workshop_ University of Portmouth (Portsmouth, UK), supplement 1.
The relevant passage reads:
'Dromaeosaurids and carcharodontosaurids are expected to be present
in Wealden Group faunas in view of their prevalence in the Cedar
Mountain Formation (Albian) of Utah and Cloverly Formation (Albian)
of Montana, and indeed some preliminarily described material
indicates that they are. Likewise it is possible that baryonychids
were a part of Wealden-equivalent North American faunas' (Naish
Other speculations might concern _Microvenator_-like oviraptorosaurs,
dromaeosaurids and the very unusual new Wealden theropod we are
working on at the moment. Stay tuned for news on all! Incidentally,
at SVPCA I asked Dr. David Norman about his views on _Iguanodon
lakotaensis_ (in the _Altirhinus_ paper he synonymises it with _I.
bernissartensis_, meaning that we have the same dinosaur SPECIES in
both Lower K N. America and Europe). He confirmed that both were
"... it cannot be denied that while the average fossil specimen may
not supply as much information (as many characters for analysis) as
the average neontological specimen, palaeontology does contribute a
wealth of organisms that would not be known otherwise" (Schoch 1986).