For over 150 years the type section of the Trenton Group at Trenton Gorge, New York has remained a premiere region for studying diverse Upper Ordovician faunas. The gorge is the post-Pleistocene erosional creation of West Canada Creek, a tributary of the Mohawk River , and in its present state over 200 feet of rock is exposed along its cliffs and waterfalls. For this large volume of rock, only a small amount of geologic time is recorded, allowing for an incredible degree of information to be gathered on a single fauna. The fossils of the Trenton Gorge have long held the attention of great paleontologists such as James Hall, Theodore G. White, Charles Doolittle Walcott, and Percy E. Raymond. Paleontological study of the gorge has origins that trace back to 1824 when James E. DeKay first described and named a trilobite found there as Isotelus gigas, currently one of the most studied species from the Trenton. James Hall would be the first to publish a serious study focusing on the Trenton Group and in 1847 the first book of his multivolume series was put in print. In this text he named many new species of fossil invertebrates from the Trenton and the list grew with each new volume.
In the latter half of the 20th century paleontologists continued to research the New York Trenton Group. During the late 1970's through mid-1980's Robert Titus detailed the lower, middle, and upper fossil communities of the Trenton Group. His three paper series includes studies of species distribution across stratigraphic and facies intervals. Several quarries located outside the gorge that exhibit extraordinarily high quality preservation have provided a unique opportunity to study the extinct organisms from the Trenton, the most prominent being the Walcott-Rust Quarry. It is a site that was discovered in the late 1800's by C.D. Walcott and noted for its beds rich in complete trilobites. The latest developments involved the re-opening of the quarry in the 1990's by Thomas E. Whiteley, and a study that led to the revision of the trilobite layers by Brett et al. in 1999.
The objective of this section is to provide an extensive catalogue consisting of the fossils found in and around the Trenton Group type section at Trenton Gorge. The Museum of Comparative Zoology at Harvard University stores all of the fossils displayed in this catalogue. Only species found in the collection are listed, each given a detailed description and one or more images of a corresponding specimen. Of the Trenton Group fossils in the collection, which number in the thousands, only the best preserved examples and type specimens are shown. The terminology and morphology are covered for each group by way of detailed anatomical drawings and definitions of advanced morphologic terms. The chief locality from which the majority of these fossils were collected has been the Walcott-Rust Quarry. Special attention is given to the history and research on this quarry, with an overview of its importance in relation to MCZ collections and to the study of Trenton Gorge.