Geology Prof. Emeritus Study Published | St. Lawrence University

Geology Prof. Emeritus Study Published

Chapin Professor of Geology Emeritus J. Mark Erickson has been studying the fossil fish that swam the Western Interior Seaway of North America 65 million years ago during the time that T. rex was hunting in Montana and western North Dakota. 

With two colleagues aiding in the study that began more than 30 years ago, his research has now been published in a 94-page monograph, titled Chondrichthyan and Osteichthyan Paleofaunas from the Cretaceous (Late Maastrichtian) Fox Hills Formation of North Dakota, USA: Paleoecology, Paleogeography, and Extinction.  This work documents the presence of 36 species of sharks, skates, rays and ratfish as well as 20 species of bony fish that were part of the marine ecosystem known as the Fox Hills Sea in North and South Dakota just before the end-Mesozoic extinction event and ecosystem collapse. 

Four new species were discovered during this study and three of these, Cretalamna feldmanni, Dasyatis northdakotaensis, and “Myliobatis” foxhillsensis are described in this work which is published as Number 398 of the Bulletins of American Paleontology, the oldest paleontological series in North America.  The highly regarded research series is sponsored by the Paleontological Research Institution of Ithaca, New York, owners of the Museum of the Earth, of which Dr. Erickson is a Trustee Emeritus.

Erickson’s co-authors are John W. Hoganson, North Dakota State Paleontologist Emeritus, and F. D. Holland, Jr., University of North Dakota Professor Emeritus of Geology and Geological Engineering. This study helps to document the ecological and paleogeographical conditions that pertained at the time of the great extinction of more than 70 percent of species on Earth. Millions of years were required for the Earth to recover from this event.