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Maastrichtian marine reptiles of the Mediterranean Tethys



From: Ben Creisler
bcreisler@gmail.com

Another recent paper not yet mentioned:

Nathalie Bardet (2012)
Maastrichtian marine reptiles of the Mediterranean Tethys: a
palaeobiogeographical approach.
Bulletin de la Société Géologique de France 183(6): 573-596
doi: 10.2113/gssgfbull.183.6.573
http://bsgf.geoscienceworld.org/content/183/6/573.abstract

A global comparison of coeval Maastrichtian marine reptiles
(squamates, plesiosaurs, chelonians and crocodyliformes) of Europe,
New Jersey, northwestern Africa and Middle-East has been performed.
More than twenty outcrops and fifty species (half of them being
mosasaurids) have been recorded. PEA and Cluster Analysis have been
performed using part of this database and have revealed that marine
reptile faunas (especially the mosasaurid ones) from the Mediterranean
Tethys are clearly segregated into two different palaeobiogeographical
provinces: 1) The northern Tethys margin province (New Jersey and
Europe), located around palaeolatitudes 30-40°N and developping into
warm-temperate environments, is dominated by mosasaurid squamates and
chelonioid chelonians; it is characterized by the mosasaurid
association of Mosasaurus hoffmanni and Prognathodon sectorius. 2) The
southern Tethys margin province (Brazil and the Arabo-African domain),
located between palaeolatitudes 20°N-20°S and developping into
intertropical environments, is dominated by mosasaurid squamates and
bothremydid chelonians; it is characterized by the mosasaurid
association of Globidens phosphaticus as well as by Halisaurus
arambourgi and Platecarpus (?) ptychodon (Arabo-African domain). These
faunal differences are interpreted as revealing palaeoecological
preferences probably linked to differences in palaeolatitudinal
gradients and/or to palaeocurrents.

On a palaeoecological point on view and concerning mosasaurids, the
mosasaurines (Prognathodon, Mosasaurus, Globidens and Carinodens)
prevail on both margins but with different species. The
ichthyophageous plioplatecarpines Plioplatecarpus (Northern margin)
and Platecarpus (?) ptychodon (Southern margin) characterise
respectively each margin. The halisaurine Halisaurus is present on
both margins but with different species. Of importance, the
tylosaurines remain currently unknown on the southern Tethys margin
and are restricted to higher palaeolatitudes. Chelonians (bothremydids
and chelonioids) are respective of each margin, which probably
indicates lower dispersal capabilities compared to mosasaurids. The
relative scarcity of plesiosaurs and crocodyliformes could be linked
to different ecological preferences. The noteworthy crocodyliforme
diversity increase in the Palaeogene is probably linked to mosasaurid
extinction during the biological crisis of the K/Pg boundary.