Connecticut, despite its modest size, holds a significant place in the study of dinosaurs. The state’s unique geological history has preserved substantial evidence of prehistoric life, offering a window into the Mesozoic Era. Its fossilized footprints, in particular, make Connecticut a notable location for paleontological research.
Ancient Connecticut’s Landscape
During the Mesozoic Era, the Late Triassic and Early Jurassic periods (230 to 190 million years ago), the landscape of what is now Connecticut was vastly different. Pangaea was beginning to break apart, forming rift valleys across eastern North America. The Connecticut River Valley is one such rift basin. Its geological activity created conditions favorable for fossil preservation.
The climate was warmer, as the region was closer to tropical latitudes. These valleys filled with water, forming lakes and river systems bordered by floodplains. Sediments like mud, sand, and volcanic ash accumulated in these basins, trapping and preserving organic matter and traces of ancient life. These lakebeds and shorelines were conducive to the fossilization of skeletal remains and, more commonly, footprints.
The Dinosaurs of Connecticut
While dinosaur footprints are abundant, skeletal remains from Connecticut are rarer due to preservation conditions. The state has yielded body fossils that illuminate the types of dinosaurs present. Among the most notable is Anchisaurus polyzelus, discovered in North America in 1818, one of the first scientifically verified dinosaur bones.
Anchisaurus polyzelus was a small sauropodomorph, an early relative of long-necked sauropods. Adults measured 6.6 to 13.1 feet long and weighed 60 to 70 pounds. This herbivorous dinosaur likely moved on two legs and possessed robust limbs, suggesting agility in its ancient forested habitat.
Another find is Podokesaurus holyokensis, a small, lightly built Early Jurassic theropod. This carnivorous dinosaur, about 3 feet long, was discovered in 1910. Its original fossil was later lost in a fire.
The Story in the Footprints
Connecticut is recognized for its collection of dinosaur footprints, also known as ichnofossils. These trace fossils formed when dinosaurs walked on soft ground, such as muddy shorelines or riverbanks, leaving impressions. These impressions would harden, often by drying in the sun, before being covered by subsequent layers of sediment like mud or ash. Over millions of years, these layers compacted into sedimentary rock, preserving the tracks.
Footprints provide insights into dinosaur behavior, gait, and size that skeletal fossils cannot. Common track types found in Connecticut include Grallator, Eubrontes, and Otozoum.
Grallator tracks, 2 to 6 inches long, were made by small, bipedal theropods, suggesting swift movement. Eubrontes, the state fossil of Connecticut, are larger three-toed prints, 12 to 16 inches long, made by a substantial bipedal theropod, possibly Dilophosaurus. Otozoum tracks are rarer and larger, showing four toes, and made by a large herbivore, possibly a phytosaur or early sauropodomorph. These trackways illustrate a diverse array of dinosaurs moving through the ancient landscape.
Connecticut’s Enduring Dinosaur Legacy
The dinosaur discoveries in Connecticut have advanced the understanding of the Mesozoic Era, particularly the Triassic and Early Jurassic periods in eastern North America. The abundance and quality of fossil footprints offer direct evidence of dinosaur activity and ecology. These findings contribute to understanding early dinosaur evolution and their presence on Pangaea.
Connecticut’s paleontological heritage is accessible to the public at Dinosaur State Park in Rocky Hill. This park protects one of the largest dinosaur track sites in North America, with hundreds of tracks preserved under a geodesic dome. The site serves as a research and educational resource, allowing visitors to engage directly with the evidence of prehistoric life. Ongoing study of these traces continues to reveal details about the dinosaurs that once inhabited this region.