top of page
  • amkbschl

Fossil Bones of the Connecticut Valley

Updated: Apr 2

Wooden Anchisaurus logo

East Windsor’s Anchisaurus can lay claim to being the first dinosaur bones scientifically studied in America, but they aren’t the only bones from the Connecticut Valley.  Fossil bones are rare in New England and not as big as the famous skeletons of Tyrannosaurus, Triceratops, and other dinosaurs of the American West. But that doesn’t mean there aren’t some fascinating finds. Here are some other fossil bones found in Massachusetts and Connecticut.

Illustration of Anchisaurus

“The Bones from the Armory”

During blasting for new construction at the Springfield Armory in the 1850s, several fossil leg and arm bones were discovered and later determined to be Anchisaurus. The fossils are housed at the Beneski Museum of Natural History in Amherst, Massachusetts.

“The Bones from the Bridge”

In 1884 workers at a sandstone quarry in Manchester, Connecticut discovered Anchisaurus bones in a block of stone. Though paleontologists quickly rescued the specimens, several blocks containing more fossils were incorporated into a bridge over Bigelow Brook.

In 1969 the Connecticut highway department was preparing to demolish the bridge. Yale professor John Ostrom met with the construction crew and was able to acquire the remaining fossils from the blocks.

Illustration of Podokesaurus


Discovered in 1910 near Mount Holyoke, Massachusetts by paleontologist Mignon Talbot, this fossil consisted of portions of the body, limbs, and tail.

Podokesaurs was a slender, long-necked, chicken-sized dinosaur from the Early Jurassic period related to the more well-known Coelophysis. Its hollow bones would have made it a light, swift predator that hunted small reptiles and mammals in the underbrush.

Its full scientific name, Podokesaurus holyokensis, means “swift-footed lizard of Holyoke”.

The original specimen of Podokesaurus was unfortunately lost in a fire in 1917. Today several casts are preserved at museums in Massachusetts and Connecticut.

In 2022 Podokesaurus was named the state dinosaur of Massachusetts.

An illustration of Colobops


The skull of this small, lizard-like reptile was discovered in 1965 during highway construction between Meriden and Middletown but was not given a scientific name until 2018. Its name means “shortened face”, referring to its blunt, triangular snout.

Colobops lived during the Late Triassic, and would have hunted small insects, worms, and other invertebrates. It is believed to be distantly related to the tuatara of New Zealand.

An illustration of Hypsognathus


A skull and other bones of this possum-sized reptile were found in Late Triassic sandstone from Meriden. Other fossils have also been found in New Jersey and Nova Scotia.

Hypsognathus was likely an herbivore and had several large spikes on its head that would have protected it from predators.

Its name means “high jaw”, referring to its broad snout.

An illustration of Aetosaurus


This cat-sized Late Triassic reptile was an herbivorous, land-dwelling relative of crocodiles and alligators. Its back was covered with hard, flat scales like pieces of plate armor that protected it from predators. It had an upturned, pig-like snout that may have been used to dig around in the soil for tubers and roots.

Fossil back plates of Aetosaurus were found near New Haven in 1893 by Othniel Charles Marsh, the paleontologist who collected many of the famous dinosaur skeletons in Yale’s Peabody Museum.  Marsh originally called the fossil Stegomus, “roof-shoulder”, in reference to the plates covering its back and shoulders like the shingles on a roof.  In 1998, though, scientists discovered that this fossil was actually the same species as Aetosaurus fossils known from the Petrified Forest site in Arizona. Thus the name Stegomus was dropped and the fossil was re-assigned to Aetosaurus, which means “eagle-lizard” in reference to the slightly bird-like look of the creature’s skull.

An illustration of Stegomosuchus


Armored rectangular back plates from this raccoon-sized reptile were discovered in the late 19th century near Longmeadow, Massachusetts. The man who discovered the fossil took it home and kept it near his front door, exposed to the elements, for about seven years before paleontologists became aware of the specimen and were able to formally study it. 

Initially, the fossil was thought to be from the herbivorous Stegomus, but a later study showed that it was actually a lithe, land-dwelling carnivore related to crocodiles. The specimen was thus renamed Stegomosuchus which means “Stegomus crocodile”.

An illustration of Erpetosuchus


This land-dwelling crocodile-relative lived in the Late Jurassic. It was about the size of a fox and probably would have had a similar hunting style, chasing small animals through the brush.

Most specimens of Erpetosuchus are known from Scotland, but a skull of this crocodilian was found near New Haven in 1995. This is because the East Coast of the US, the islands of the UK, and Western Europe would have all been pressed together in the giant landmass Pangea during the Triassic. Thus, many fossils of the same or similar species can be found on both sides of the Atlantic.

An illustration of the coelacanth Diplurus


These large fish lived in the rivers and lakes that once ran through the Connecticut Valley during the Late Triassic and Early Jurassic. Flattened impressions of their bodies are often found in shale deposits in both Massachusetts and Connecticut, as are their fossilized poop which are called coprolites.

Diplurus closely resembled its living relative, the coelacanth. Both fish belonged to an unusual group known as sarcopterygians or “lobe-finned fish”- so named because their fins are on short, bony “arms”. Land-dwelling animals evolved from another group of sarcopterygians.

Anillustration of the fish Semionotus


Fossils of many different species of fish can be found in shale rocks throughout the Connecticut Valley. These fish, which were distantly related to gars, had hard, triangular scales that are preserved as shiny, black impressions in the stone.

Semionotus is one of the more commonly found fossil fish species, but there were likely dozens, if not hundreds of species all specialized for specific habitats in the lakes and wide rivers that filled the Connecticut Valley during the Late Triassic and Early Jurassic.

18 views0 comments

Recent Posts

See All


bottom of page