Dinosaurs That Roamed Our Area

Back in 1972 when Paul Olsen, a leading paleontologist, professor at Lamont Doherty and a member of the prestigious National Academy of Sciences, was a student at Yale, he and a friend noticed a large flat expanse of rock that had recently been exposed while visiting the friend’s father in Blauvelt. They knew that rock in the area had been determined to be about 215 million years old. (Rock is dated by examining the decay of radioactive minerals.) Within an hour, the duo had discovered about 20 prehistoric footprints in the densely wooded area between Route 303 and Greenbush Road.

“We found three-toed tracks, about 4 inches by 5 inches, in a purplish red rock that had been filled with white sandstone, which made them quite visible,” Paul said. “We determined they were left about 210 to 215 million years ago by a creature about the size of a large turkey. It probably had feathers that looked like fur and ran on its hind legs, using its slender tail for balance.” The tracks had been made by an Atreipus, a plant-eating dinosaur or a silesaur, an earlier relative, from the Triassic Period. These were the first dinosaur fossils ever found in New York State.

Except for a small wedge that underlies Rockland County where, 230 million years ago, there would have been a lake and mud flats around the time dinosaurs first evolved, most rocks in the state were formed 350 to 1.2 billion years ago, eliminating the possibility of any footprints left in wet sediments. At this time, the continents were connected in one giant land mass called Pangea that ran from pole to pole with Africa connected to North America. Over the next one hundred million years, continental drift opened up the land, creating the Atlantic Ocean and our present valley. Larger dinosaurs would have been present in our area as time went on. The very first, nearly complete, dinosaur skeleton was collected in 1858 in Haddonfield, N.J.

Dinosaurs became considerably larger with the increase of food reliability in the later Mesozoic Period. T. rex, one of the largest, existed around 66 to 68 million years ago in western US. They all met their demise 66 million years ago when an asteroid, six miles wide, hit the Yucatan Peninsula in Mexico, sending columns of vaporized rock into the atmosphere incinerating forests and creating tsunamis around the globe. Only small mammals and birds survived the impact. We humans (Homo sapiens) arrived about 200,000 years ago, many millions of years after dinosaurs roamed the earth.

The tracks Olsen and his friend discovered were brought to the New York State Museum in Albany, where they are on display. “We returned to the site and found others, but they are hard to see because they are in mottled rock,” Paul said. “The best time to see them is on a sunny winter morning.” Since then Olsen has found additional footprints, including those of unquestionable small dinosaurs and a variety of other animals, from several other Rockland sites.

The tracks found by Olsen and his friend have again been in the news. A proposal before the Orangetown Town Board to rezone 17 acres, located between Route 303 and Greenbush Road that includes the area with the prehistoric footprints, was made by developer William Brodsky who wanted to build 68 townhouse-style two- bedroom condominiums on about eight acres currently zoned for single-family homes and light industrial uses. The proposal has been dropped because of neighborhood opposition.