Palaeontology

Were dinosaurs warm or cold-blooded ?

By T.K. Randall
June 2, 2015 ·  26 comments

Were the dinosaurs warm or cold-blooded ? Image Credit: CC BY 2.5 Brian Engh The question over whether the dinosaurs were cold-blooded like today's reptiles and fish or warm-blooded like mammals and birds has remained a topic of controversy and debate for years.

While many experts have settled on the idea that dinosaurs were actually somewhere in the middle with both cold-blooded and warm-blooded traits, a new study has this week thrown another spanner in the works by suggesting that they were in fact almost certainly warm-blooded.

"Upon re-analysis, it was apparent that dinosaurs weren't just somewhat like living mammals in their physiology," said study author and palaeontologist Michael D'Emic of Stony Brook University.

"They fit right within our understanding of what it means to be a ‘warm-blooded' mammal."D'Emic's re-analysis focused on two main aspects of the original study with the first being the scaling of yearly growth rates to daily ones in an attempt to standardize comparisons, a discrepancy that he contends failed to take in to account variable growth rates throughout the year.

In addition D'Emic also argues that birds, which are now commonly believed to be the modern-day descendants of dinosaurs, are warm-blooded and that therefore dinosaurs probably were too.

"Separating what we commonly think of as 'dinosaurs' from birds in a statistical analysis is generally inappropriate, because birds are dinosaurs - they're just the dinosaurs that haven't gone extinct," he said.

While his findings are unlikely to be sufficient on their own to prove that dinosaurs really were warm-blooded his efforts will no doubt fuel further study in to this 65 million-year-old mystery.

Source: Discovery News | Comments (26)

Tags: Dinosaurs