Table of contents
- Why does Montana have so many dinosaurs?
- How many dinosaurs have been found in Montana?
- Which dinosaurs lived in Montana?
- Which dinosaur fossils have been found in Montana?
- What did Montana look like during the dinosaurs?
Why does Montana have so many dinosaurs?
The rocks in Montana’s Hell Creek formation date back to the exact period of the dinosaurs. Today, much of this land is undeveloped and easy to access. Paleontologists have explored this region extensively over the past 100 years and discovered many dinosaur fossils.
Below, I answer this question in greater detail. Here are the four main reasons Montana has so many dinosaurs.
Reason #1: The right rocks
Montana’s rocks date back to the right time period when dinosaurs roamed North America. In other regions of the United States, such as New York, the rocks are too old.
During the late Cretaceous Period (about 65 million years ago), the Rocky Mountains rose, pushing the Western Interior Seaway back and uncovering the land of present-day Montana. Great rivers meandered through the state in a hot, humid climate, depositing sediment in areas where the dinosaurs were living.
This sediment formed the rocks of what is now called the Hell Creek formation in eastern Montana, where paleontologists have found many of Montana’s dinosaur fossils.
Reason #2: The right geography
Many of eastern Montana’s rocks are exposed, easy to see, and easy to access. As it gradually erodes, it exposes more fossils. The lack of tree cover and relatively flat landscape makes it easy for paleontologists and fossil hunters to access different areas to search for and excavate dinosaur fossils.
Reason #3: Undeveloped space
Montana consists of large swaths of undeveloped, undisturbed land, ideal for paleontological digs.
In highly developed regions of the world, such as major cities, there may have been dinosaur fossils, but they were either destroyed or covered up by manmade structures.
Reason #4: Local efforts
The western United States has been a popular dig site for 200+ years. Paleontologists have searched for dinosaur fossils in Montana for much of this time.
As Montana gained a reputation for dinosaur fossils in the 20th century, more fossil hunters and paleontologists arrived in the area to explore its soil.
Other regions of the world, such as China and Argentina, are becoming more known for their dinosaur fossils. As researchers discover more fossils in these regions, more digs take place.
Sources: Montana Department of Transportation, David Moscato
How many dinosaurs have been found in Montana?
According to the Paleobiology Database (PBDB), 940 dinosaur fossils have been found in Montana:
- Total fossils found: 940
- Most discovered genus: Hadrosauridae (74 fossils)
- Most common time period: Maastrichtian (432 fossils)
Montana is the third state with the most dinosaur fossils, behind Wyoming (2nd) and California (1st). Researchers have found 75 different dinosaur species in Montana.
Meanwhile, the PBDB has recorded no dinosaur fossil discoveries in five states – Kentucky, Rhode Island, New Hampshire, Wisconsin, and Vermont.
Which dinosaurs lived in Montana?
During the Cretaceous Period, the Deinonychus, or “raptor” in the 1993 Jurassic Park film, called Montana home. Other dinosaurs that lived in present-day Montana during this time include the burrowing Oryctodromeus, Maiasaura, and Troodon.
Millions of years later, during the late Cretaceous period, many of the well-known dinosaurs, such as Triceratops, T. rex, and Ankylosaurus, all lived in present-day Montana. Pterosaurs ruled the skies instead of birds.
Which dinosaur fossils have been found in Montana?
Paleontologists have found over 75 dinosaur species in Montana, including:
- Gryposaurus
- Diplodocus
- Maiasaura
- Stegosaurus
- Tyrannosaurus Rex
- Elasmosaur
- Fearsome, plated Allosaurus
Find a full list of dinosaurs found in Montana: Were there dinosaurs in Montana?
Interesting fact: After a lifetime of studying dinosaurs, Montana-based paleontologist Jack Horner has developed an unconventional theory about what dinosaurs actually looked like. He believes they donned bright colors and had features similar to birds, like in the images below:
Find out who Jack Horner is in our article, “Who is Jack Horner?“.
What did Montana look like during the dinosaurs?
During the time of dinosaurs, the land of present-day Montana experienced different climates, each lending to a different ecosystem. During the Triassic period, parts of this area were a dry, arid desert. Throughout the Jurassic and the Cretaceous periods, the Western Interior Seaway covered most of the region, while other parts were humid, swampy lowlands.
Find out what Montana looked like during the dinosaurs here.
Which US state has the most dinosaurs?
The U.S. state where the most dinosaur fossils have been found is Arizona. More than 200 dinosaur fossils have been found in Arizona from 15 different dinosaur species, including Tyrannosaurus, Dilophosaurus, and Sonorasaurus. The Natural History Museum in Arizona displays the largest collection.
Discover Montana’s dinosaur history on the Montana Dinosaur Trail
Today, 14 locations throughout Montana offer insight into the state’s Dinosaur history. Together, they comprise the Montana Dinosaur Trail. Find out where each site is located and what to see and do at each one in my article Montana Dinosaur Trail.
Header image: US Geological Survey
