Posted on 11/18/2003 11:09:31 AM PST by Tumbleweed_Connection
The Wyalusing Rocks were supposed to be just a scenic stop on Jennifer Elick's drive to Tuckhannock, where she and other Pennsylvania geologists planned to meet. But then a spot of white caught Elick's eye in the red sandstone of those Bradford County cliffs. "I thought to myself, 'Well, that's either a fossil, a fish fossil, or it's bird doo,'" said Elick, an assistant professor of geological and environmental sciences at Susquehanna University. "I reached up, grabbed it and looked at it, and it had teeth. It was a jaw, and it filled the palm of my hand, and was crumbling all over. That was pretty exciting." What Elick found was a remnant of Pennsylvania's deep past, a period when what is now Bradford County was a tropical river delta, sitting at the border of land and sea. Since finding that first fossil, the jaw of a Sarcopterygiian, or lobe-finned fish, in the spring of 2002, Elick has removed four plant and animal fossils from Wyalusing Rocks in northeastern Pennsylvania. All are denizens of the late Devonian period dating to some 350 million to 360 million years ago: The lower jaw of a Sarcopterygiian, a prehistoric carnivore that moved along river bottoms. A nearly intact Bothriolepis, an armored bottom-feeder with a tail like a shark. The sand-filled stump of an Eospermatoperis, a tree that grew in the marginal areas where salt and fresh water met. And Archaeopteris, thought to be the first tree to form actual forests. Jon Inners, geologist manager for the Pennsylvania Geological Survey, said it's not surprising that Elick would find these fossils at Wyalusing Rocks, a 400-foot cliff over the Susquehanna River, about 130 miles north-northwest of Philadelphia. Another fossil bed in the region, Red Hill, is renowned for Devonian fossils, and the Great Catskill Delta in New York and Pennsylvania is yielding more and more finds. "But it's always neat because it's so rare," said Inners, who had examined the same cliffs before without finding anything. "These rocks were red rocks, stuff that formed on river flood plains and river channels. And in these oxidized sediments fossils are mostly destroyed, they rot away. It takes rather peculiar conditions to preserve them," Inners said. "Somehow, the oxidizing waters did not get through to the fish that were buried there enough to decompose them. There were some hard parts that would have been preserved, but it's just rare to find fossils as complete as she found them." The Sarcopterygiian jaw is so detailed that even the teeth, some almost an inch long, are clearly visible. The fish itself was probably at least 3 feet long, Elick said. But the most interesting fossil might be the one Elick left behind -- a trace fossil, or the remnant not just of a creature, but of that creature's movement. About 9 feet long and 6 inches wide, the trace appears to be left by a Sarcopterygiian, a fish whose fins had the same bone structure as arms on other vertebrates. The Sarcopterygiian is also thought to have been a precursor to amphibian development (although Elick points out that amphibians probably would have been around during the late Devonian, when her fossils were made). The trace appears as a shallow trough, as if left by something skimming just above the silty soil of a river bottom. Traces along the side of the trough could have been made by the fish's fins. "There's no other organism besides amphibians at this time that would have been large enough and is known to have made or left tracks," Elick said. "There are organisms that would have been big enough, but they would have left a different trace." In prehistoric circles, dinosaurs get all the glory. But Elick said she hopes her discoveries on Wyalusing Rocks might get people interested in the creatures that ruled the world millions of years before dinosaurs came along. "It's kind of neat to find out that there were large fish -- fish with teeth that were 2 centimeters long -- swimming in your back yard 350, 360 million years ago," Elick said. "It's kind of like having a dinosaur in your back yard."
I was wondering what Helen Thomas was doing in Pa.
Yes, I was behind her today on highway 60 between Moon Township and the airport...
Grouchy old bitty too...
Almost sounds like a Yogi-ism...
I'm not sure what makes this 'rare'.
Between the coal deposits and the limestone, there's always been lots of fossils in Pennsylvania. Other sedimentary rocks as well: sandstone, shale, slate. Used to come across 'em all the time when I was a kid. Nothing really impressive, just outlines of leaves or seashells and such. But I was just a kid poking around with rocks. You'd think the professionals would routinely come up with better specimens than what I did.
Yep. "Rare" is a bit puzzling.
Give me a clue, Sir Chazz. I can't tell which it is from the picture you posted.
Not that I remember...
I was only 8~12 years old during my poking around in rocks phase.
If I did, I'd guess it was more likely in the coal than the limestone,
But heck, it's unlikely we were even looking for fossils, they were just there...
Yeah, they were cool to look at, at first,
but they get pretty old when we were actually hoping to find Indian arrowheads.
(It's kinda like fishing for bass or walleye, and catching nothing but bluegill. You get tired of rebaiting the hook and tossing the fish aside.)
Anyway, we were more likely to pick-up and keep some piece of river rounded and polished pebble "lucky stone" (quartz maybe?), simply because it was pretty and more colorful than ordinary rocks that we came across. We'd save those in a pouch where we kept our cats-eye marbles.
Never did find any arrowheads. By the time I was old enough to know what I was doing, my interests had turned more to sports.
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