THE NEW YORK PALEONTOLOGICAL SOCIETY PRESENTS
THE ANALYSIS AND INTERPRETATION OF
FOSSIL VERTEBRATE TRACKWAYS
Dr. Bret Bennington
Professor of Geology, Hofstra University
Sunday, November 20, 2011 1:45 P.M. Room 319
American Museum of Natural History New York City
Trackways are an important component of the fossil record. As trace fossils (or ichnofossils) trackways record the actions of a living, moving animal and provide invaluable insights into the behavior and paleobiology of extinct vertebrates. Trackways are also common in strata that are otherwise devoid of vertebrate fossils and thus fill gaps in the fossil record of vertebrate evolution. Nowhere is this better illustrated than in the fossil record of trackways in the Triassic-Jurassic strata of the Connecticut Valley and Newark rift basins in the Northeast. Here, dinosaur trackways provide both revelations and questions about early dinosaur behavior, morphology, diversity, and evolution.
Using examples from throughout the fossil record, Dr. Bennington will review the basics of trackway ichnology and how trackways are analyzed to determine such things as trackmaker identity, posture, behavior, and speed. He will then discuss a detailed analysis of the trackways found at Dinosaur State Park, CT. Here, hundreds of trackways apparently made by the same species of theropod (carnivorous) dinosaur have baffled ichnologists for decades. However, by applying some basic statistical analyses to these trackways, it is possible to get closer to understanding how many animals were responsible for making these trackways and how they were interacting with one-another.
He will also discuss the how these and other trackways from east coast rift basins have been studied to better understand the nature of the Triassic-Jurassic mass extinction and the ascent of dinosaurs that followed. Finally, we will look at two examples of how trackway finds have upended established estimates of the timing of vertebrate evolution, demonstrating how paleontologists are still mislead by the expectation of a scala natura in evolution and by the spotty nature of the vertebrate fossil record.