The Middletown Press (Middletown, CT)
Peabody Museum brings you back to Age of Dinosaurs
Once, instead of black bears and raccoons, dinosaurs walked around your backyard — small ones, sizable ones, plant-eaters and meat eaters.
And like Barbie, they stepped lightly — at least as lightly as a dinosaur could.
“Like Barbie, they walked on their toes,’’ said Susan Butts, director of collections and research at Yale University’s recently reopened, splendid Peabody Museum of Natural History.
The big stars of the museum’s Burke Hall of Dinosaurs are back on display — the brontosaurus, the triceratops, the Rudolph Zallinger mural that stretches across the wall of the hall.
But there is also a display of the fossil tracks dinosaurs left when they strode what is now Connecticut.
Only it wasn’t Connecticut. It was a very small patch of the supercontinent Pangea.
The earth’s tectonic plates are slowly, constantly shifting the earth’s land masses around. About 250 million years ago, these land masses came together to create Pangea.
Then, Pangea slowly began pulling apart, creating rift valleys — tears on the Earth’s surface.
One of those rift valleys became the Atlantic Ocean. But there were other places where the was only a partial teaer.
What is now the Connecticut River Valley was once a prehistoric rift valley. So was the Pomperaug River Valley in Southbury and Woodbury.
As this was happening there was a mass extinction on Earth about 252 million years ago, killing off 95 percent of life forms on Earth. Scientists believe it could have been caused by an asteroid strike, a huge series of volcanic eruptions, or the release of methane gas from the oceans.
“It’s called the Great Dying,’’ Peabody’s Butts said.
But after extinctions, new creatures survive, evolve, and take up the niches lost species once filled. The Great Dying led to the Age of Dinosaurs.
It was nothing like the landscape we know. Flowering plants and trees hadn’t evolved. Instead, Butts said, it was a world of ferns and cycadeoids — thick-barreled, plants with a crown of leaves on top, like giant pineapples.
We know there were dinosaurs in Connecticut largely by the tracks they left in the Hartford Basin. Dinosaur State Park in Rocky Hill has dinosaur tracks across its landscape. The Peabody has some on display, including Eubrontes giganteus — the state fossil.
The tracks of these dinosaurs are about 220 million to 200 million years old. The creatures that made them were bipedal — they walked upright on their hind legs.
They left their tracks in muddy sediments covered over by other sediments and preserved through the millennia.
There is one fossil display at the Peabody that has tracks made by both a bigger and a smaller dinosaur. It’s dotted with a pattern of raindrops. The dinosaurs were walking in the rain.
“These are sloppy footprints,’’ Butts said.
There is one fossil — Anomoepus isadactylus — that shows a dinosaur relaxing and letting its heel down — a complete footprint.
There is also, remarkably, an entire dinosaur fossil — bones, not tracks — of a small plant-eating dinosaur called Anchisaurus. It was about 6 feet long and weighed about 75 pounds. It was found in the 19th century in rock formations near Manchester.
“It was found near where the Buckland Hills Mall is today,’’ Butts said,.
Butts said most of the dinosaurs that made these tracks were the size of a big dog, or a small pony.
“Maybe bigger,” she said, pointing to the fossil. “That’s a big print.’’
The reason we don’t have more intact fossils in the state, she said, is that they died on land. Other dinosaurs ate them. Their carcasses rotted. Winds and water carried away what was left.
The fossil record in the state stops around 200 million years ago, at the start of the Jurassic Period. Butts said the climate and geology must have shifted, so that conditions for creating fossil tracks ended.
“Sediments accumulate, then they wash away,’’ she said.
Then, 66 million years ago, an asteroid struck the Earth off the Yucatan Peninsula in Mexico. It was a cataclysmic event of tsunamis and global firestorms. The Age of Dinosaurs ended in a burning planet.
But some flying dinosaurs survived — they evolved into birds. Crocodiles, turtles and some amphibians survived. So did some small burrowing mammals The Age of Mammals was about to begin.
Butts said the Peabody’s new exhibits try to tell this very long, complicated story.
“Life changes the environment,’’ she said, ‘The environment changes life, Extinctions change everything.’’