During a geology field trip in 2004, the professor told his students that a road-cut featuring rock formations near Pittsburgh International Airport was a great place to find plant fossils.

Hearing that, Adam Striegel, then a University of Pittsburgh junior, plucked up a hand-sized rock at his feet that appeared to contain the fossil of a fern frond or leaf. But on the trek, the rock became too cumbersome while he scribbled notes, so he cast it aside.

Later, having second thoughts, he found the fossil once again to show his geology professor, Charles Jones.

It was a lucky course of events.

The fern? Actually, an ancient predator's jagged teeth. The rock? Actually, a fossilized skull.

And that's not even the best of it.

When he and Dr. Jones eventually showed the fossil to David S. Berman at the Carnegie Museum of Natural History, the noted paleontologist could barely believe his eyes.

He beheld the fossilized skull of a trematopid that looked a bit different from two other existing trematopid fossils. Further study convinced museum experts that the skull was a new genus and species of carnivorous amphibian that lived about 300 million years ago in Western Pennsylvania and was among the first to spend most of its time on land rather than in water.

On Monday Dr. Berman, the museum's curator of vertebrate paleontology and three museum colleagues -- Amy C. Henrici, vertebrate paleontology collection manager; David K. Brezinski, associate curator of invertebrate paleontology; and Albert D. Kollar, collection manager of invertebrate paleontology -- published their findings in the Annals of Carnegie Museum, which describe the newly discovered trematopid. The article includes evidence it represents one of the earliest examples of terrestrial vertebrate to adapt to warmer, drier climates of the Upper Pennsylvanian region, which was tropical at that time.

The find produced an electrifying moment for Dr. Berman.

"I have had five to 10 great discoveries in my 40-year career, and you live for those moments," he said. "The only thing that could be better is if I had made the discovery myself."

Museum paleontologists have named the new trematopid, Fedexia striegeli, to honor its discoverer and the FedEx Corp, which owns the property where it was found.

Mr. Striegel, a 29-year-old White Oak native now an elementary school teacher in Rockville, Md., said he remains amazed at what happened after he picked up that "rock" six years ago.

"I can't believe my name will be known forever as this species of animal," he said. "Who can say that they have a species of animal named after them?"

And to think he almost tossed it aside.

This Trematopidae, as its family of amphibians is known, provides evidence of amphibians emerging from water to live on land in the later part of the Pennsylvanian Period, 318 million to 299 million years ago. While it likely returned to water to lay eggs, it spent most of its time as a terrestrial hunter, as evidenced by its canine-like teeth.

Fedexia striegeli represents how animals adapted to the changing environment in an age when ice buildup on the South Pole caused oceans to recede, creating more dry land as the Appalachian Mountains simultaneously began rising in this region.

The new species is not only the first trematopid fossil to be found in Pennsylvania, but only the third from the Pennsylvanian Period. Dr. Berman discovered one in New Mexico, and a third was found in Kansas. Fedexia lived about 80 million years before dinosaurs first appeared.

During the Early Permian Period, 295 million to 270 million years ago, trematopids became more diversified and numerous, resulting in more abundant fossil evidence.

The Fedexia fossil skull is "remarkably well-preserved" a museum news release notes.

"Unlike many other fossil finds, the fossil skull remained three-dimensional and did not suffer post-mortem crushing over time by the compaction of rock formations above it," it states. "The preservation of the skull is so precise that even the middle-ear bone, known as the stapes, remains perfectly intact and in its correct position, a very rare discovery in fossils."

Anatomical features including the novel shape and size of its eye orbit size, but especially the shape of its greatly elongated external nares or nostril-like openings, among other anatomical features, identify Fedexia as a new genus and species of trematopid. The fossil suggests an animal up to 2 feet long that resembles a giant salamander.

Dr. Berman said he got permission from FedEx to keep the fossil. It will be preserved for future research in the museum collection. The Carnegie also is making casts of the skull to present to FedEx, Dr. Jones and Mr. Striegel.

But the most surprising aspect of the story, Dr. Berman said, was its discovery by an amateur "who had no prior experience in recognizing invertebrate fossils in the rock -- a talent that usually takes years to develop."

As a junior, Mr. Striegel chose the geology course to satisfy a science requirement. Now he's forever immortalized in scientific literature.

"I honestly just reached down and picked up a rock," he said. "I wish there was something more amazing about it. The professor had just said we might find something there and mostly likely we would find plant fossils.

"I picked it up and studied it a little bit and thought I saw a fern."

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