Global Aspects of Dinosaur Distribution and Evolution

Hans-Dieter Sues

Late Jurassic dinosaurian assemblages show close taxonomic correspondence over wide geographical ranges. Presently available if meager evidence suggests that this is also the case for Early Cretaceous communities. Cretaceous dinosaurian assemblages of Campanian and Maastrichtian age show considerable geographical differentiation but also some wide-ranging genera. Northern Hemisphere terrestrial ecosystems were dominated by hadrosaurs and ceratopsians, both herbivores with advanced capabilities for oral food-processing, whereas Southern Hemisphere biota were characterized by the abundance of titanosaurid sauropods, which relied on gut processing. Very close taxonomic similarities exist between the Campanian and early Maastrichtian dinosaurian assemblages of Mongolia and we tern North America, which, in part, is matched by similarities among other tetrapods such as mammals. Endemic dinosaurs in the Southern Hemisphere appear to reflect major changes in continental configuration. Some evidence exists for interchange of faunal elements between North and South America. In absence of late Maastrichtian dinosaurian assemblages from most regions, scenarios concerning the terminal Cretaceous extinction of the Dinosauria should be regarded with caution because they are exclusively based on the conditions in western North America.

AAPG Search and Discovery Article #91030©1988 AAPG Annual Convention, Houston, Texas, 20-23 March 1988.