In 2004 a local geology student found the skull of Fedexia striegeli in Western Pennsylvania. The specimen was lying at the base of a road cut that exposes the Casselman Formation. The Casselman is the formation above the Ames Limestone. Locally where I dig, the estimated layer in the strata might not exist. It is much higher than the local hills that surround me. The geologic age is not exact, however. The fossilized skull was found at the base rather than pulled from the hillside. Estimates place it to be 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 discovery of amphibians on land by 20 million years.
Location of Discovery
Upon discovering the fossil, Mr. Striegel originally thought he had found a fern fossil. The discovery happened on land owned by Fedex, which is near the Pittsburgh Internation Airport in Moon Township. Thus, the genus was named Fedexia for Fedex, and the species is striegeli for the discoverer.
Trematopids in the Pennsylvanian
Before Fexedia was discovered, only three examples from the Trematopidae family have ever been found within the Pennsylvanian period of time. Previous finds included Anconastes vesperus (CM 41711) in 1986 in New Mexico, and Actiobates peabodyi in Kansas in 1973.
Pennsylvanian Trematopid Discoveries
|1986||New Mexico||Anconastes vesperus|
Perceived Age of Pennsylvanian Trematopid Discoveries
In the type species paper (Berman, Henrici, Brezinski, Kollar), there is a chart (Fig 3) showing geological age information of these three discoveries. Correlation of the species and climate is shown with sea level, precipitation and glacial frequency and extent. By using this chart, I made rough estimates of the perceived ages of these three species, +/- 3 million years a piece.
|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 sits below the Ames Limestone. The red clay they described was 37 feet thick and the fossils were found 4 feet above the base.
In the paper published in the Annals of the Carnegie Museum, Volume 78, No 4, the Pitcairn specimens were mentioned when showing local relation to the discovery of Fedexia.
More Information about Fedexia striegeli
- ScienceDaily – Fossil of early terrestrial amphibian discovered
- Article on Wikiedia
- D.S. Berman, A.C. Henrici, D.K. Brezinski, A.D. Kollar (2010) – A New Trematopid Amphibian (Temnospondyli: Dissorophoidea) from the Upper Pennsylvanian of Western Pennsylvania: Earliest Record of Terrestrial Vertebrates Responding to a Warmer, Drier Climate – Annals of Carnegie Museum Vol 78, No 4.
More Information on Pennsylvanian Trematopids and Vertebrate Fossils
- D.S. Berman , R.R. Reisz & D.A. Eberth (1986) – A new genus and species of trematopid amphibian from the Late Pennsylvanian of north-central New Mexico
- T.H. Eaton (1973) – A Pennsylvanian Dissorophid Amphibian from Kansas
- E.C. Case – Description of Vertebrate Fossils from the vicinity of Pittsburgh, Pennsylvania (Pages 234-241) – Annals of Carnegie Museum Vol 4.