Paleontologists reported this week that a meat-eating amphibian roamed the badlands of Pennsylvania some 300 million years ago.
“Amphibians are tiny vertebrates that live in damp environments and require water to exist.
This category includes frogs, toads, salamanders, and newts. Through their extremely thin skin, they can all breathe and absorb water.
Amphibians also have unique skin glands that make protein. Some carry water, oxygen, and carbon dioxide into and out of the animal. Others battle illnesses caused by bacteria or fungi. And at least one is employed for defense in each species.”
A team led by David Berman of the Carnegie Museum of Natural History in Pittsburgh describes Fedexia striegeli in the current Annals of the Carnegie Museum journal. The creature’s name is a thank-you to Federal Express, which owns the road-cut land on which the fossil skull of the creature was found, and its amateur finder, Adam Striegel.
Based on its five-inch-long skull, Fedexia “records the earliest occurrences of vertebrates adapted to a terrestrial existence, “says the study, “primarily living and feeding on land.” The creature, which lived about 70 million years before the first dinosaurs, likely only returned to the water to lay eggs.
The dating of the fossil comes from a chemical comparison of the skull to the rock layers of the western Pennsylvania road cut from which it tumbled in 2004. It was then discovered by Striegel, then a senior at the University of Pittsburgh. “What is particularly amazing about this discovery is that it was made by an amateur who had no prior experience in recognizing vertebrate fossils in the rock, a talent that usually takes years to develop,” said Berman in a statement.
Then, near the equator, the geology of western Pennsylvania indicates that North America enjoyed a dry climate at the time when Fedexis roamed, following a wetter period that saw the emergence of some of the first land animals tens of millions of years earlier. Yet aquatic amphibians continued to dominate the Pennsylvanian vertebrate assemblages during this episode, says the study, which follows earlier suggestions that the drying-out of swampy terrain spurred the evolution of land-dwelling creatures whose ancestors mostly lived in the water.
