New Study Claims T. rex Was Warm-Blooded

That’s the claim of a new study, published in Science Advances. This study analyzed three fossil T. rex teeth from the Hell Creek Formation in Montana, comparing the results against an analysis of crocodile teeth from the same formation. A popular science article claims the results of the study “settles the debate” on the question of T. rex’s internal temperature, placing it at 97 degrees Fahrenheit.

The article states:

This places T. rex’s internal temperature ahead of today’s cold-blooded reptiles and even sloths, but short of their avian descendents [birds], which range between 104 and 109 degrees Fahrenheit.

(Notice right away the assumption of dinosaur-to-bird evolution!) But how does a tooth reveal a creature’s internal temperature? Well, the article explains:

About 10 years ago, paleontologists developed a way to learn an extinct species’ blood temperature by examining certain rare carbon–oxygen bonds that form in fossilized bone. As [study coauthor] Eagle explained, tooth enamel offers the best medium for samples because its large crystalline composition remains extremely resilient to deterioration for millions of years. . . .

Using a dental drill, Eagle and his team extracted fossilized enamel that they then dissolved in phosphoric acid. This released carbon dioxide gas filled with the coveted isotopic bonds. From there, they employed a mass spectrometer to determine the chemical ratios after pressurizing the CO2. Subsequent analysis led them to conclude the T. rex’s blood temperature was about 97 degrees Fahrenheit.

So does this really “settle the debate”? Was T. rex definitively a warm-blooded creature?

Well, that kind of language is definitely overstating the case. The study authors write in the abstract, “Measurements of three T. rex teeth from the Late Cretaceous Hell Creek Formation yield a temperature of 36.3 ± 2.5°C.” In other words, the study authors indirectly measured the body temperature, not the metabolic rate.

I asked AiG’s Joel Leineweber, a paleoartist and lifetime “dinosaur nerd,” his thoughts on this new study, and he shared with me these four problems with it:

1. You can’t directly measure metabolism in something that’s dead. So everything else is guesswork.
2. They claim multiple lines of evidence in the paper, but so far all lines of evidence for warm-blooded dinosaurs that I’ve seen rely on at least one of these two assumptions: a. environmental conditions (remember: the global Flood changes those) or b. phylogeny (in this case, assuming that dinosaurs evolved into warm-blooded birds). Both of these are totally different in a creation science model.
3. The study itself is pretty cool, measuring the temperature of tooth formation in T. rex and fossil crocodiles and comparing the results (that part seems like good observational science). But there are some problems:
• small sample size (two T. rex individuals and only three teeth)
• crocodiles are semiaquatic so not a great comparison
• one crocodile had tooth formation warmer than the tyrannosaurs
• the researchers admit you can’t determine metabolism from body temperature alone
4. A preflood climate was likely warmer than today, and larger-bodied ectotherms tend to preserve heat better than smaller ones, so none of this seems very conclusive. Large dinosaurs may have approached something called mesothermy because of their size (leatherback sea turtles accomplish something like this), but it’s all very inconclusive.

Your assumptions about the past drive your interpretations of the evidence in the present.

In other words, your assumptions about the past drive your interpretations of the evidence in the present. So, no, it hasn’t been proven that T. rex was an endotherm (warm-blooded). Evolutionists assume slow processes over millions of years; therefore, their conclusions about the climate of the supposed Late Cretaceous are going to be different than how a creationist, starting with the history in God’s Word, is going to view past climate conditions or a particular rock layer. We believe, based on the fossil record, the world before the Flood was quite different and was much warmer, with only one continent. This impacts how a creature like T. rex would function and what we find in the fossil record.

After all that, what can we conclude?

How you answer that question depends largely upon your beliefs about the past.

Thanks for stopping by and thanks for praying,
Ken

This item was written with the assistance of AiG’s research team.