Hot on a Cold Trail

Another rock imprinted with the shape of a three-toed track has surfaced on Long Island. And it may have been made by a dinosaur that actually lived here.

``If it's real, it may be the first dinosaur fossil that originated on Long Island,'' said Columbia University paleontologist Paul Olsen, a leading expert on fossils.

The impression may have been made by a close relative of Tyrannosaurus rex, according to Olsen, who recently examined the sandstone slab in his laboratory and then surveyed the beachfront bluffs at Eatons Neck, where an amateur historian found the red rock 44 years ago after a storm.

``I can't be definitive about it, but it probably is a [dinosaur] track, and a very rare track indeed,'' said Olsen, who is writing a book on dinosaur tracks.

If it's genuine, the track would be the first direct evidence of what experts have long suspected: The same kinds of dinosaurs that thrived in nearby Connecticut, New Jersey and upstate New York, where fossils are common, also lumbered around the swampy coastal plain that would later become Long Island.

Long Island's only confirmed dinosaur track has held that distinction only since October, 1997, when Olsen declared that a smaller piece of sandstone found on a beach north of Riverhead is definitely marked with a dinosaur footprint. But the beast that made that track, which dates from the end of the Triassic period 200 million years ago, almost certainly didn't live here, Olsen said. The rock originated in Connecticut and was carried south by a glacier about 25,000 years ago to Riverhead's Roanoke Landing.

The Eatons Neck rock appears to be much younger -- probably a mere baby from the Upper Cretaceous period about 80 million years ago -- and has characteristics that suggest it originated in the place that eventually became the North Shore of Long Island.

The conventional wisdom among experts was that dinosaur fossils might never be found here. In a Newsday article on the subject in Chapter 1 of ``Long Island: Our Story,'' geologists were quoted explaining that any local tracks or bones were buried by massive amounts of sand and gravel brought here later by bulldozing glaciers.

Fossil buff Glenn Magee read that Sept. 29 story and thought he had a rock that proved the conventional wisdom wrong. He arranged to have Olsen examine an apparent track in a glacier-borne rock he found near his Roanoke home in the mid-1970s. When Olsen declared that the track was made by a Ceolophysis, or a close relative of the 6-foot-tall meat-eating dinosaur, Magee's discovery was ballyhooed as Long Island's first confirmed dinosaur fossil.

The publicity triggered a barrage of calls from other local rock collectors who thought that they, too, had found dinosaur fossils.

Most of those calls didn't pan out. But Mitzi Caputo of the Huntington Historical Society remembered a rock the society had inherited almost 10 years ago from amateur historian Mary Voyse of Asharoken. Voyse's legacy to the society also included an article from the Nov. 19, 1953, edition of the Northport Journal detailing her discovery and describing how the rock was identified as a dinosaur track by an expert at the American Museum of Natural History in Manhattan.

That was enough to capture the interest of Olsen, who decided to come to Long Island and visit the places where Voyse and Magee made their respective discoveries.

``It's a bit of a detective story really,'' Olsen said on a sunny December afternoon as he walked along the shore at Eatons Neck, crouching every few feet to study the rocks littering the beach.

Like any good detective story, the clues in this one don't all point in the same direction.

The seeming footprint in the Eatons Neck rock is a puzzle because almost all of the dinosaur fossils in the Northeast United States date from the Triassic or Jurassic periods about 200 million years ago. But the imprint on the Eatons Neck rock is too wide to match any known dinosaur track from those older geologic periods, Olsen said. In addition, two of the three ``toes'' of the track run off the edge of the rock, suggesting that the shape might not be a real dinosaur track.

It's surprising that the rock was found at Eatons Neck because rocks carried there by glaciers probably would have originated in an area of Connecticut in which virtually no dinosaur fossils have been found. And the rocks on the beach at Eatons Neck are almost all much younger than the Triassic and Jurassic rocks in which most fossils are discovered.

At Roanoke Landing, on the other hand, the clues all add up. Roanoke is due south of a treasure trove of dinosaur fossils in Connecticut, and the beach at Roanoke is loaded with Triassic and Jurassic red rocks -- many of them already broken open by fossil hunters who have heard about Magee's discovery. And unlike the Voyse imprint, the three-toed footprint Magee found is complete and even has claw marks for each toe.

By the end of his afternoon on Long Island, Olsen had come to a conclusion he didn't expect. Since most of the rocks at Eatons Neck date from the much younger Upper Cretaceous period, he said, the apparent track Voyse found there may be an extremely rare Cretaceous fossil, made by a dinosaur that lived on the future site of Long Island only about 15 million years before the entire dinosaur line abruptly ended in extinction 65 million years ago.

That would explain why the Eatons Neck rock lacks the linear scratches that cover the Roanoke rock -- a sign that Voyse's rock wasn't carried by a glacier. It would also explain the wide span of the footprint, since the toes of some Cretaceous dinosaurs were widely splayed. At least two types of dinosaurs could have made the track: smaller relatives of T-rex known as tyrannosaurids, or beaked carnivores called ornithomimids, Olsen said.

Not everyone is fully convinced by Olsen's theory. Herb Mills, a Nassau County geologist who has examined both rocks, said the Eatons Neck rock doesn't look like any piece of Cretaceous rock he's ever seen on Long Island. The rock may actually be much older, he said, which would mean the apparent footprint was either transported by a glacier or wasn't really made by a dinosaur.

``All I can say is, I think the matter needs to be looked into further,'' said Mills, who is planning an excursion with Olsen to take a close look at the rocks at Eatons Neck.