Search the Site
Dinosaurs' gravity    .Earth expansion .Latest News.Publications  .
My book details....
The third edition of my book is widely available
An explanation for the gigantic scale of prehistoric life
Book reviews....
Tyrannosaurus rex, the king of the dinosaurs, is commonly shortened to T. rex. It was one of the best known of the dinosaurs, a meat eater approaching the mass of an elephant with the killing instinct of a tiger.

Perhaps the best description of what this dinosaur might have been like comes from one of the world’s leading palaeontologists, Professor Robert Bakker, who is widely credited with the dinosaur renaissance of fast active dinosaurs. In his book, The Dinosaur Heresies, he described why he believes that T. rex was a fast and agile hunter. The legs were built for speed with massive muscles capable of propelling T. rex forward at great speed. The lung and heart cavities were large to enable him to pump the blood and oxygen required by his massive leg muscles.


Unfortunately, in complete contrast to this renaissance of a fast T. rex, various studies of the leg muscles and bones of T. rex show it would struggle to run at all in our present gravity.


The paradox of an animal that looks like it could run but can’t in our present gravity is resolved once we realise that it evolved to run in a reduced palaeogravity, the ancient surface gravity on the earth. This would have enabled this elephant sized animal to be a fast hunter.


One fundamental technique to quantify palaeogravity is to compute weight against mass estimates of ancient animals. This technique has been applied to four specimens of T. rex, representing some of the most complete theropod dinosaur skeletons known. The results using T. rex and a range of other life indicate that they lived in a reduced palaeogravity of about 0.63g at 67 million years ago.






Updated  20 Dec 2023


Tyrannosaurus rex

This is ‘Stan’ the T. rex, on display at the Natural History Museum in Manchester, UK.

Share this page