Fedexia striegeli - Fossils of Parks Township

In 2004, a local geology student found the skull of Fedexia striegeli in Western Pennsylvania. The specimen lay at the base of a road cut exposing the Casselman Formation. The Casselman is the formation above the Ames Limestone. The geologic age is not exact. The fossilized skull was found at the base rather than pulled from the hillside. Estimates place it at around 305 million years old.

Finding any sort of amphibian fossil in Pennsylvania would be a huge deal. This specimen, found by Adam Striegel, a University of Pittsburgh student, pushed back the earliest known record of the Trematopidae, a group of carnivorous amphibians, by almost 20 million years.

Illustration of Fedexia striegeli by N. Tamura. — Illustration of Fedexia
striegeli © N. Tamura

Location of Discovery

Upon discovering the fossil, Mr. Striegel originally thought he had found a fern fossil. The discovery occurred on land owned by FedEx near the Pittsburgh International Airport in Moon Township. Thus, the genus was named Fedexia for FedEx, and the species is striegeli for the discoverer.

Fedexia striegeli at Carnegie Museum — A cast of Fedexia striegeli (CM 76867) is on display at the Carnegie Museum of Natural History. The teeth are likely what Mr. Striegel thought were fern leaves.

Trematopids in the Pennsylvanian Subperiod

Before the discovery of Fexedia, only three reports from the Trematopidae family came from the Pennsylvanian subperiod of time. Previous finds included Anconastes vesperus (CM 41711) in New Mexico (Berman et al 1986) and Actiobates peabodyi in Kansas (Eaton 1973).

Pennsylvanian Trematopid Discoveries

2004	Pennsylvania	Fexedia striegeli
1986	New Mexico	Anconastes vesperus
1973	Kansas	Actiobates peabodyi

Perceived Age of Pennsylvanian Trematopid Discoveries

In the type species paper (Berman, Henrici, Brezinski, Kollar, 2010), there is a chart (Fig. 3) showing geological age information of these three discoveries. The correlation between species and climate is shown using sea level, precipitation, glacial frequency, and glacial extent. Using this chart, I made rough estimates of the perceived ages of these three species, each within ±3 million years.

302 mya	New Mexico	Anconastes vesperus
305 mya	Pennsylvania	Fexedia striegeli
306 mya	Kansas	Actiobates peabodyi

Other Vertebrate Fossils in Pittsburgh, Pennsylvania

While scarce, vertebrate fossils can be found in the Pittsburgh region. In the Annals of the Carnegie Museum, Volume 4 (1906-1908), E.C. Case describes vertebrate fossil remnants found in Pitcairn, PA. They appear to be within the Pittsburgh Red Beds, which sit below the Ames Limestone. The author reported the fossils from four feet above the base of the 37-foot-thick red clay.

In the paper published in the Annals of the Carnegie Museum, Volume 78, No. 4, the Pitcairn specimens were mentioned in relation to the discovery of Fedexia.