Connecticut State Fossil

Dinosaur Tracks

(Eubrontes Giganteus)

Adopted in 1991.

Dinosaur Tracks, Eubrontes Giganteus, was adopted in 1991 as the state fossil.

The Connecticut Valley is the world's foremost dinosaur track locality. Many different types of fossil track impressions have been found in the Valley's sandstone of the early Jurassic period (200 million years ago).

Description

Eubrontes, a large three toed track, was designated the State Fossil in 1991. Although no skeletal remains of the specific track making dinosaur have been found, the shape, size, and stride of the Eubrontes indicate that the animal was closely related to the Western genus Dilophosarus. Two thousand Eubrontes tracks were discovered on a single layer of rock in Rocky Hill in 1966 and subsequently Dinosaur State Park was created for their preservation and interpretation. This Registered Natural Landmark site receives visitors from throughout the world.

Today New England is a charming and picturesque land, covered by beautiful rolling hills and dense pine and birch forests. But, 200 million years ago, during the dawn of the Jurassic, this corner of the American northeast was covered by a much different landscape. At this time the Atlantic Ocean was just beginning to form, and to make room for this new body of water, present day North America and Europe split into two landmasses. Along the line of this break formed a giant rift valley, which was gradually filled with sediment carried by rivers and streams. This gradual deposition left over 16,000 feet of sediment in the valley, and also left large, open mudflats, which were the home to countless species of dinosaurs and other reptiles. Sheets of mica covered these flats, preventing mud from sticking to the feet of these dinosaurs as they walked. The result: thousands of exceptionally well-preserved footprints!

Today these footprint layers, which make up the East Berlin and Portland Formations, are exposed and often quarried in Connecticut. Several species of fossil footprints fill these strata, including those of the bird-like Grallator and the crocodile-like Otozoum. But, the most common print is likely that of Eubrontes, a track which likely belonged to a mid-sized, bipedal predatory dinosaur. A typical Eubrontes print ranges from 40-50 centimeters (16-20 inches), and contains three long toes, often with evidence of a heel. Based on the large size of these tracks, the Eubrontes trackmaker must have been over one meter high at the hips and 5-6 meters long. One possible culprit is Dilophosaurus, the familiar crested dinosaur from Jurassic Park. The size of Dilophosaurus is basically consistent with these measurements, but nothing short of finding a fossilized Dilophosaurus track in a Eubrontes print will conclusively pinpoint this Jurassic theropod.

The first Eubrontes print was discovered and named in 1845 by the famous paleontologist Edward Hitchcock. Throughout the next century several more Eubrontes prints were discovered throughout Connecticut and Massachusetts-including some evidence of possible Eubrontes social order, until the mother lode of all dinosaur prints were discovered in Rocky Hill, Connecticut in 1966. While digging the foundation for a new State Highway Department testing laboratory, workmen made a remarkable discovery. About four feet beneath the surface they discovered hundreds of three-toed dinosaur tracks. Paleontologists, including John Ostrom, were called to the scene, where they recommended that the site be protected. Several local newspapers backed their plan, and a mere three weeks later Governor John Dempsey designated the site a state park. Today this area is known as Dinosaur State Park, and is one of the most popular tourist destinations in New England. Nearly 600 tracks are exhibited in their natural state under the park's large geodesic dome, providing paleontological thrills for those traveling through the rolling, historical state of Connecticut.