A Dino Discovery

New research shows that dinosaurs weren’t warm-blooded or cold-blooded

June 16, 2014

Dinosaurs were found to be very physically active which led scientists to believe that they were warm-blooded. New research shows that they were not warm-blooded.

For years scientists have debated whether dinosaurs were warm-blooded like mammals, or cold-blooded like reptiles, fish and amphibians. Now, scientists have found that these prehistoric creatures were somewhere in the middle, according to a new study in the journal Science.  This new information shows that dinosaurs are very different from today’s animal species that are all either warm or cold-blooded.

Scientists studied many kinds of dinosaurs in the study. This is a sarcophagus.

Scientists studied many kinds of dinosaurs in the study. This is a sarcophagus.

"I think we were all surprised by this," said University of New Mexico Professor Felisa Smith who supervised the study. "The idea certainly took some getting used to.”

The last dinosaurs roamed the earth more than 60 million years ago. However, there is always more to discover about these ancient creatures. 

A study by a team of scientists led by John M. Grady of the University of New Mexico’s biology department studied many different kinds of dinosaurs in their research. They looked at growth rate, temperature and body size of various species.

Middle Ground

There are certain characteristics that make warm-blooded creatures different from cold-blooded creatures. Warm-blooded creatures like humans and other mammals can control their body temperature. They also eat a lot, and burn calories quickly. They have a more active lifestyle than cold-blooded creatures.

Cold-blooded creatures such as reptiles do not control their body temperature internally. Instead, they must use sunlight to keep warm, and they move much more slowly. Cold-blooded creatures do not need to eat very much. Their bodies slow down in colder temperatures.

Dinosaurs are in the middle because they do not fully regulate their internal temperature, but their temperature does not only rely on their environment either. This is called mesothermic. The UNM study shows that this feature helped dinosaurs and allowed them to thrive for so many years.

The prehistoric creatures now join a group of other animals that are not completely warm-blooded or cold-blooded. This category includes great white sharks, leatherback turtles and tuna. Great whites and tuna are mostly cold-blooded but their muscles work to heat their blood. The leatherback turtle uses a similar process to stay warm.

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