ALASKAN DINOSAURS AND THE ASSEMBLING OF BERINGIA

Beringia is the name given to northeastern Asia, northwestern North America, and the surmised land connection between the two regions. Beringia is also a political entity since 1991 with the signing of an international park agreement between the United States and the former Soviet Union. Speculation on a land connection between the two continents dates to the late 16th century. The relationship between fluctuations in sea level and glacial advances and retreats inspired the concept of a dry land connection between Asia and North America. By the 1930s enough data had been gathered that Hulten proposed the name Beringia for the land bridge. By this definition, Beringia is a Pleistocene concept.

Continued work extended the Beringian concept back in time to the mid- to early Tertiary based on a number of floral and faunal characteristics that emphasize a rich history of organismal similarity between northeastern Asia and northwestern North America. The discovery of dinosaur remains in Aniakchak National Monument establishes that during the Cretaceous Alaska supported a vast terrestrial ecosystem capable of supporting a megaherbivore fauna and also provides insight into the origins of Beringia.

Based on recent tectonic reconstructions, the possibility that faunal migrations are not directly correlated with glacio-eustatic sea level changes, and new dinosaurian discoveries, the concept of Beringia can, and should be formally extended back in time to at least the Turonian and perhaps the Aptian/Albian. This implies that the concept of Beringia is rooted in its accretionary history rather than in a climatic history.