Dinosaur heart update: just a lump of mud?

by , Ph.D.

14 October 2000

When the first-ever discovery of what appeared to be a fossilized dinosaur heart was announced earlier this year, it caused a sensation.1,2 X-ray scans of the fossilized interior of a Thescelosaurus dinosaur appeared to reveal detail of a heart anatomy more like that of birds and mammals (which are warm-blooded), than of crocodiles or other living reptiles (which are cold-blooded). Many interpreted this finding as evidence that dinosaurs were warm-blooded and had a high metabolic rate like birds. Some evolutionists claimed this as further support for the currently fashionable idea that birds evolved from dinosaur ancestors, notwithstanding recent spectacular failures and frauds (e.g. Archaeoraptor—Phony ‘feathered’ fossil).

At the time, we reported on this finding (Fascinating four-chambered fossil find!), showing that if the structure was in fact a dinosaur heart, it created even more difficulties for the dinosaurs-evolved-into-birds theory, while its rapid fossilization and intricate design was perfectly consistent with the biblical account of history.

Now though, there are increasingly loud protests from other scientists that the fossil ‘heart’ sticking out of the dinosaur’s ribcage is not a heart at all, but rather is …  just a lump of mud!3,4 A University of Kansas dinosaur researcher called it ‘a fairly ordinary concretion’ and said that X-rays cited as evidence of a heart showed only ‘a kind of vague image’. He and other researchers are increasingly sceptical of the ‘heart’ claims, pointing out that the X-rays could just as likely be showing fossilised mud.

At the time of publication of the original finding in the respected Science journal, several paleontologists were somewhat sceptical and wanted to inspect the evidence personally before accepting that the fossil was indeed a heart. Others also challenged the anatomical interpretations, arguing that key parts of the fossil were missing that would otherwise indicate an anatomy more like reptiles living today. Now two scientists are reported to have submitted a rebuttal article to Science, but the editors have not yet indicated whether it will be published.

Published: 15 February 2006


  1. Fisher, P.E. et al., Cardiovascular evidence for an intermediate or higher metabolic rate in an ornithischian dinosaur, Science 288(5465):503–505, 2000. Return to text.
  2. Morell, V., Revealing a dinosaur’s heart of stone, Science 288(5465):416–417, 2000. Return to text.
  3. Dinosaur ‘heart’ could be just a lump of mud, <www.ananova.com/news/story/sm_77436.html?nav_src>, 9 October 2000. Return to text.
  4. New debate over a dinosaur heart, <www.newsweek.msnbc.com>, 6 October 2000.
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