The 200-Million-Year-Old Footprints Down the Road from my Home

I read recently that Rocky Hill, my new hometown, is “a typical bedroom community.” Nonsense. How many “typical bedroom communit[ies]” boast thousands of authentic dinosaur tracks from the Jurassic era, hundreds of which can be visited inside a whimsical building for nominal fee?

lost world.jpg

On a recessed floor shielded by a geodesic dome, the Connecticut Dinosaur Park and Arboretum at 400 West Street publicly shares about 600 dinosaur footprints — all authentic ancient tracks (not facsimiles). After the footprints were made — producing the tracks — they were covered over by many years of silting from nearby erosion; the silting became sandstone, and the footprints and tracks have been preserved for 200 million years (give or take a few decamillennia). They spent the better part of that time hidden underground, but are now safely indoors where they are carefully protected yet still easily viewed in the same spots they occupied all along.

Just how long is 200 million years?`

If we imagine 5 human generations in each century, and pretend those humans might have been able to walk side-by-side with dinosaurs (which they never did), one of those humans could have been your eight-millionth-great-grandmother (give or take a few thousand generations).

That’s how long 200 million years is.

The current estimate these days for the earliest appearance of earthly humans now hovers around 300,000 years ago, in light of the recent discovery of a jawbone in modern-day Morocco. That means the Rocky Hill dinosaurs most likely romped in the Connecticut Valley a solid 199,700,000 years before those earliest Moroccan hominids wandered around verdant northern Africa. So, no eight-millionth-great-grandmother. Sorry.

The Discovery

The fossilized tracks in the state park alongside West Street were discovered by a lucky construction accident. In August 1966, a man most often referred to only as “bulldozer operator Edward McCarthy” was driving an excavation machine, digging into the earth to prepare the site for a state lab. According to several accounts, he turned over a slab of rock and spied some three-toed prints he found curious. He brought the prints to the attention of his supervisor, and — by all accounts — New England dinosaur and geology scholars, along with the state itself, acted quickly to assess the site, and to protect it from collectors and entrepreneurs who might have quickly stripped away the treasures. State officials turned the site into an official state park, which can be visited now, more than 5 decades after the discovery.

One of the dinosaur footprints at Dinosaur State Park in Rocky Hill, Conn.

While the known prints in Rocky Hill are estimated to number around 2,100, there could be many, many more. “The Connecticut Valley is full of them,” said Dinosaur State Park and Arboretum Manager Margaret “Meg” Enkler, who has run the facility since 2003. It is the 600 under the unusual 55,000-square-foot geodesic dome — a design developed by R. Buckminster Fuller, an American architect and inventor — that people arrive to see during museum hours.

The rest of the known prints — 2,000 or so — were reburied under plastic, foam, and about 4 feet of fill, to preserve them and to save the state the cost of making them available for public view. There are no easy estimates of how many footprints might remain undiscovered, but the known tracks are not all that rare, and you can visit others elsewhere in the Connecticut Valley — especially in Massachusetts.

Keep in mind that The Connecticut Valley, where many tracks have been found, is not precisely the same as the Connecticut River Valley. The Connecticut Valley was created by enormous land masses shifting around the globe over aeons, separating continents into the shapes we know today; the river valley was created by erosion and silting from the southerly flow of water from northern Vermont. (In fact, the Connecticut Valley reaches well beyond Connecticut.)

OK, but is it odd, with all these dinosaur tracks ranging along the length of the Connecticut Valley, that there haven’t been more discoveries of bones or other fossils from the dinosaurs themselves? Enkler says there is a reasonable explanation. These hundreds (or thousands) of dinosaur footfalls sit in an ancient flood plain that was flanked by eroding mountains — something like the Jurassic era version of a Ziploc bag waiting to keep the tracks fresh for aeons. By contrast, says Enkler, “the conditions good for preserving tracks are not nearly as good for preserving whole dinosaurs.” Disappointingly, “There are very few dinosaur bones in Connecticut,” she says.

Then Who Made the Tracks?

dino wide
The usual suspects.

The prevailing theory is that the Rocky Hill tracks “were made over 200 million years ago by a carnivorous dinosaur similar to Dilophosaurus,” reports one source, and Enkler agrees.

Dilophosaurus (“two-crested lizard”) is a genus (a genetic grouping) of theropods — “beast-footed,” predatory, carnivorous dinosaurs that lived in what is now North America more years ago than most of us can grasp (but at least 175 million). Over the approximately 200 million years since the Mesozoic period (Triassic — development of dinosaurs and mammals; Jurassic — development of birds and flight; and most recently Cretaceous — ending with mass extinctions, which seem to have skipped over the birds), the theropods kept evolving into larger creatures — until time produced the ultimate beast of a theropod: Brontosaurus, the massive thunder lizard.

Where Bronto might measure 72 feet long (a little longer than a regulation bowling lane) and could weigh 15 tons (around the same as a typical subway car), the Dilophosaurus, which arrived much earlier in the Mesozoic, was significantly smaller — measuring perhaps 23 feet long (a third as long as Bronto, or that bowling lane) and weighing around half a ton (just about the same as a concert grand piano).

The Dilophosaurus (Jurassic era) “was, relatively speaking, slender and lightly built, and though the skull was proportionally large, it was delicate. The snout was narrow, and the upper jaw had a gap below the nostril.”

In its time, the Dilophosaurus was a dominant predator — which may be why author Michael Crichton presented it as a vicious antagonist in his novel “Jurassic Park” (later made into a film by Steven Spielberg).

But speculation aside, there is no conclusive evidence that the Dilophosaurus is the same beast that romped through the Mesozoic flood plain in Connecticut, leaving behind these prints. In fact, at present, there is no definitive name at all for the dinosaur that made these tracks — although the tracks themselves do have a name: Eubrontes. Loosely speaking, it’s Greek for “true-thunder,” and it applies only to the footprints — not to any creature that left the footprints behind. (The name eubrontes was established in 1845 by the early Massachusetts paleontologist Edward Hitchcock — for a long time a professor at Amherst College, where the Beneski Museum of Natural History carries on the Hitchcock legacy.)

There is plenty of evidence of who unearthed the tracks in Rocky Hill in 1966: Edward McCarthy, then in his 20s and the operator, at the time, of a bulldozer — a modern beast in its own right. His D8H was loud, probably red, and was made by the venerable Caterpillar Co. Unlike the dinosaurs that roamed the Connecticut Valley, many of the 46,800 D8H Cats that were loosed on the world have been preserved. One, from 1966, was still running well enough to be for sale on youtube in 2014 — at the respectable age of 48.

At first, McCarthy seems to be something of a mystery — more or less disappearing from print after several references as the venerable “bulldozer operator Edward McCarthy” — but he is definitely not a myth.

“I met him once, personally,” said Enkler, “when we were celebrating the 50th anniversary of the discovery” in 2016. “He just kept working with heavy equipment, I think,” after the discovery of the tracks.

And we will meet him soon, in another post.

Wide shot
The vastness of the protected footprints.


Once the tracks had been discovered, the goals were to preserve them, to catalog them, to study them. Eventually, these processes produced what Enkler calls ‘“new knowledge,” along with a safe space for members of the scientific community and the public alike to view the tracks, along with the displays that offer explanations and perspective for the whole site.

Besides the large, central, eerily-lit room that contains the tracks, the state park offers smaller examples of footprints and several examples of what dinosaurs from the early Jurassic period looked like (according to the best hypotheses of the scholars), along with the natural history dioramas that have been the meat and potatoes of natural history museums since the mid-19th century, and the backbone of elementary school science fairs for decades.

The site is appropriate year-round for young, old, and in between, and during the warmer months, it welcomes visitors to take part in outdoor activities, such as digging for gems and fossils, casting a plaster model of a fossil, and hiking the 2 miles of trails through the arboretum.

A recent grant will make possible an updated, 300-foot boardwalk across a red maple swamp – all designed to accommodate wheelchairs and other mobility assistance devices, opening the park grounds to more visitors than ever.


A Learning Experience
Adam Mazzadra, of South Windsor, Conn., holds Aaden, 2, while Brendt, 4, examines one of the dioramas at the museum. (Mother Diane was photographing the group.)

The park also has an extensive gift and book shop (where I happily gathered some of the published resources about the tracks).

For visitors with Charter Oak Passes, admission is always free.

For everyone else, it is always worth the modest fee, regardless of the weather or proximity of school vacation. Truly, Dinosaur State Park is not to be missed, whether your group is ages 2 to 9 or 92.


Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s