Photo on right by Charles Harringto

Interlaken's mystery fossil, bottom, and what it may have been 375 million years ago, top: a branching glass sponge, depicted in a scientific illustration after the 1870 Challenger expedition.

Cornell University paleontologists are enlisting the public's help in the search for some unusual 375 million-year-old fossils in upstate New York and northern Pennsylvania. Dating to the Devonian geological period, when an inland sea covered much of what is now the Northeast United States, the fossils are roughly the size and shape of a human hand. Some are made of black, glassy material (See "Have You Found This Fossil?" attached) while others are tan to brown in color.

They're certainly not hands, but exactly what the fossilized organisms were is not clear.

"We could be looking at the root of a branching glass sponge, something like later glass-sponge fossils reported in Pennsylvania and New York," says Cornell paleontologist John Chiment, who is leading the search. "The tops of branching glass sponges are known from the Devonian period, but they've been missing from the fossil record ever since. Or, this could be a very different organism that is unknown to science."

Chiment urges people to contribute to paleontological history by contacting him if they find similar fossils. He can be reached at (607) 255-1010, e-mail jjc1@cornell.edu. More information and photographs of the fossils -- as well as drawings of what the fossils may be -- are found at this website: http://www.geo.cornell.edu/glasssponge.html

The mysterious fossils first came to the university's attention late last year after auto mechanic Michael Potts dug a hole for a gasoline tank in Interlaken, N.Y. At about the 15-foot level, Potts noticed an abundance of limestone boulders that resembled lumpy footballs and basketballs, and planned to use the "cement basketballs" to line his horse corral.

While moving the boulders, Potts noticed odd discolorations and broke one open to reveal a glassy black structure. The mysterious object passed to a neighbor who showed it to Chiment on the Cornell commuter bus one morning. Chiment, who is an instructor in Cornell's Department of Geological Sciences and lectures frequently on the fossils of North America, recognized the object's uniqueness. Experts at Cornell and at Ithaca's Paleontological Research Institution (PRI) could not immediately identify the fossil.

Then this past December, while speaking at local schools, Chiment turned up two more: Trumansburg second grader Brandon Greene brought one in for show-and-tell, recalling that his father unearthed the object while plowing a nearby farm field and thought it might be a Native American artifact. And Romulus High School Principal Michael Midey had one from his days of leading earth science field trips in the Romulus area.

Meanwhile, a search of the scientific literature and of the fossil collections at PRI and Cornell turned up some clues:

• Fossils called Titusvillia drakei, believed to be glass sponges from about 300 million years ago, were found near Titusville, Pa., in the early 1900s.
• Around the same time, glass sponge-like fossils labeled Protoarmstrongia ithacensis were found in an rock quarry near Ithaca; these were dated to the Devonian period, about 365 million years ago. Both the Pennsylvannia and New York specimens are younger in geological terms than the hand-like fossils. Both the Titusville and the Ithaca glass sponge fossils display a distinctive nodular growth pattern. Neither has the smooth branching structure of the recently discovered fossils.
• The only living example of a branching glass sponge was hauled from the ocean depths off the Philippines in 1870 by the crew of the British Challenger expedition, the first around-the-world oceanographic survey. Not a single branching glass sponge has been found since by scientists, and the whereabouts of the Challenger specimen is uncertain.

"For all we know, today's deep ocean may have plenty of branching glass sponges," says Cornell paleontologist Sande Burr. Explaining the differences among sponge types, she notes that sponges have skeletons made of one of three kinds of materials -- silica glass, calcium carbonate or the protein of bath sponges. "Sponge fishermen who drag the deep ocean for more attractive glass sponges, like the Venus flower basket, may be throwing back branching glass sponges because they have no economic value," she says. "They're probably pretty ugly."

Cornell students in Geology 106, Chiment's class in fossil preparation, don't think so. The undergraduates are busily extracting glassy black structures from boulders that once graced the Interlaken horse corral, and they'd like to have more.

"Potentially, we're looking everywhere from northern Pennsylvania through central and western New York to the Great Lakes," Chiment says. "The southern examples will probably be younger, geologically speaking, whilet his still-unnamed older fossil is more likely to turn up farther north."

Chiment adds, "But we'd like to be surprised. We don't even know for sure what this thing is. We just know that it deserves a place in the fossil record, and we need some help putting it there."