April 20, 2000
This 66 million year old heart has recently been analyzed -- it has four chambers and a single aorta, which is quite different from existing reptiles, but is similar to modern warm-blooded animals (like birds and mammals).
If true, this discovery suggests not only that Thescelosaurus may have been warm-blooded, but that many other dinosaurs may have been warm-blooded as well. This is because we now have evidence of warm-bloodedness in both Ornithischia and Saurischia (the two major groups of dinosaurs, which diverged early in the Mesozoic Era). Thescelosaurus was an ornithischian; birds, which are known to be warm-blooded, are saurischians.
Finding fossilized soft tissue (like a heart) is extremely unusual. Soft tisssue usually decays long before it can fossilize (fossilization is a process in which rock-like minerals replace organic tissue, forming a rocky copy of the original material).
Anatomy: Thescelosaurus had a small head, a bulky body, a long, pointed tail, and short arms. It was a hypsilophodontid and an ornithischian dinosaur about 10 to 13 feet (3-4 m) long and 3 feet (0.9 m) tall at the hips; it weighed roughly 665 pounds (300 kg). This ornithopod (a Hypsilophodontid) had a small skull, cheek pouches, cheek teeth, and a beak made of horn.
Fossils: One complete specimen and 8 incomplete Thescelosaurus skeletons, including skin impressions, have been found in Wyoming, Montana, and South Dakota in the USA and in Alberta and Saskatchewan, Canada.
Rebuttal to the find from 2001: Tim Rowe, Earl McBride and Paul Sereno think that the "heart" is an ironstone concretion.
Printout on Thescelosaurus
North Carolina Museum of Natural Sciences, Raleigh, NC - where you can see Willo, the Thescalosaurus whose fossilized, four-chambered heart was found.
DinoHeart.org, a site on Willo
Information on dinosaur metabolism
A Geologic Time Chart.
Over 35,000 Web Pages
Sample Pages for Prospective Subscribers, or click below
Overview of Site|
Enchanted Learning Home
Monthly Activity Calendar
Books to Print
Parts of Speech
The Test of Time
TapQuiz Maps - free iPhone Geography Game
Biology Label Printouts
Physical Sciences: K-12
Art and Artists
Label Me! Printouts
|Search the Enchanted Learning website for:|