Wednesday, May 26, 2010

Ajkaceratops kozmai: an European Ceratopsian



A Late Cretaceous ceratopsian dinosaur from Europe with Asian affinities

1. Attila Ősi (A)

2. Richard J. Butler (B)

3. David B. Weishampel (C)

Affiliations

A. Hungarian Academy of Sciences, Hungarian Natural History Museum, Research Group for Paleontology, Ludovika tér 2, Budapest 1083, Hungary

B. Bayerische Staatssammlung für Paläontologie und Geologie, Richard-Wagner-Straße 10, Munich 80333, Germany

C. Center for Functional Anatomy and Evolution, Johns Hopkins University, Baltimore, Maryland 21205, USA

Abstract:

Ceratopsians (horned dinosaurs) represent a highly diverse and abundant radiation of non-avian dinosaurs1, 2, 3, 4, 5 known primarily from the Cretaceous period (65–145 million years ago). This radiation has been considered to be geographically limited to Asia and western North America1, 2, 3, with only controversial remains reported from other continents. Here we describe new ceratopsian cranial material from the Late Cretaceous of Iharkút, Hungary6, from a coronosaurian ceratopsian, Ajkaceratops kozmai. Ajkaceratops is most similar to ‘bagaceratopsids’ such as Bagaceratops and Magnirostris, previously known only from Late Cretaceous east Asia3, 5, 7, 8. The new material unambiguously demonstrates that ceratopsians occupied Late Cretaceous Europe and, when considered with the recent discovery of possible leptoceratopsid teeth from Sweden9, indicates that the clade may have reached Europe on at least two independent occasions. European Late Cretaceous dinosaur faunas have been characterized as consisting of a mix of endemic ‘relictual’ taxa and ‘Gondwanan’ taxa, with typical Asian and North American groups largely absent10, 11. Ajkaceratops demonstrates that this prevailing biogeographical hypothesis is overly simplified and requires reassessment. Iharkút was part of the western Tethyan archipelago, a tectonically complex series of island chains between Africa and Europe12, and the occurrence of a coronosaurian ceratopsian in this locality may represent an early Late Cretaceous ‘island-hopping’ dispersal across the Tethys Ocean.


DUDE!

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