This family of dinosaurs (a species called Oryctodromeus cubicularis) lived about 95 million years ago in what is today the U.S. state of Montana. Paleontologists discovered the Oryctodromeus fossil family in 2006.
Oryctodromeus was a burrowing dinosaur. The Montana burrow reached about half-a-meter (1.6 feet) underground, twisting and turning more than 2.1 meters (6.9 feet) along the way.
Dinosaurs, like Oryctodromeus, were terrestrial animals. This means they lived mostly on land. Today, many terrestrial animals dig burrows similar to Oryctodromeus. Can you name some burrowing land animals?
What are the benefits of having a burrow?
Oryctodromeus wasn't very big. The widest part of its body (its shoulders) was about 26-30 centimeters (10-12 inches). The burrow's tunnel was about 30 centimeters (12 inches) wide. The tunnel was a very tight fit! Why do you think Oryctodromeus dug such a narrow tunnel?
A burrow creates a "microclimate." A microclimate is a place where the environmental conditions are different from the surrounding area. Burrow microclimates are usually more moderate than the area outside the burrow. The burrow microclimate helped Oryctodromeus survive in habitats where it probably could not have survived outside. What are some of these extreme habitats?
Term Part of Speech Definition Encyclopedic Entry arid Adjective
form of movement where an animal consistently uses two legs for standing or walking.
small hole or tunnel used for shelter.
area of land that receives no more than 25 centimeters (10 inches) of precipitation a year.
Encyclopedic Entry: desert dinosaur Noun
very large, extinct reptile chiefly from the Mesozoic Era, 251 million to 65 million years ago.
conditions that surround and influence an organism or community.
group of organisms that come from the same ancestors and share similar characteristics. Family is also a classification in chemistry and math.
Encyclopedic Entry: family food Noun
material, usually of plant or animal origin, that living organisms use to obtain nutrients.
Encyclopedic Entry: food forelimb Noun
front limb of an animal, such as an arm, leg, wing, or flipper.
remnant, impression, or trace of an ancient organism.
Encyclopedic Entry: fossil habitat Noun
environment where an organism lives throughout the year or for shorter periods of time.
Encyclopedic Entry: habitat microclimate Noun
small area where the climate differs within a larger climate region, such as "heat islands" in a city.
species of small, burrowing dinosaur.
person who studies fossils and life from early geologic periods.
having to do with the North and/or South Pole.
animal that hunts other animals for food.
having to do with the Earth or dry land.