* Astronomy

To mangle an F. Scott Fitzgerald quotation, the very big hear differently from you and me.
In this case, the very big were dinosaurs weighing up to 75 tons. According to a talk by Robert J. Dooling, given Tuesday at the meeting of the Acoustical Society of America, the beasts could not hear sounds as high as humans hear.

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[youtube=http://youtube.com/watch?v=yG9P7FNtmZY]

The idea of  Tyrannosaurus rex being able to turn quickly and run down fast, agile dinosaurs has been challenged by new research published in the Journal of Theoretical Biology. The lead author, John Hutchinson, who currently works at the Royal Veterinary College, has been using biomechanics to ascertain what a typical Tyrannosaurus rex s body mass would have been, how fast it could have run and how quickly it could turn.
John and his colleagues developed a new computer modelling system that estimates the centre of mass position and the inertia (resistance to turning), which have ramifications on how T. rex would have stood and moved and what it would have looked like. The research estimates that the complete skeleton of T. rex that they modelled probably weighed in the region of 6000 8000kg in life, but some larger individuals could have been as heavy as 10 tonnes.
This unique modelling system has enabled John to estimate the turning ability of a T. rex, which has never been done before. A T. rex would have turned incredibly slowly due to its massive inertia, taking one or two seconds to turn 45 degrees - far slower than a human. The species certainly could not have pirouetted rapidly on one leg, as popular illustrations have sometimes pictured it, and other large dinosaurs, doing.
This research also adds new support, with better calculations, for the notion that large tyrannosaurs could not run at 45mph (as often pictured in popular accounts such as movies); 25 mph still seems the extreme maximum speed even with generous assumptions, as its leg muscles couldn't have been big enough for very fast running.

"Previous studies have tried to find one or two numbers to estimate the mass, whereas we did over 30 different computer models, giving a much more definite prediction.  From this we now know that a T. rex would have been front heavy, turned slowly and could manage no more than a leisurely jog" -  John Hutchinson, Lecturer in biomechanics at the Royal Veterinary College.

Biomechanical studies into large extant animals such as elephants often inform palaeontologists of how dinosaurs would have moved. However this new study has shown that a T. rex would not have walked in the same way as an elephant does, with vertical, pillar-like legs to keep its centre of mass over its feet, it needed to bend its legs considerably during standing and moving.

See also

See also

New evidence may help explain the brute strength of the tyrannosaurid, says a University of Alberta researcher whose research findings demonstrate how a fused nasal bone turned the animal into a "zoological superweapon."

"Fused, arch-like nasal bones are a unique feature of tyrannosaurids. This adaptation, for instance, was keeping the T. rexes from breaking their own skull while breaking the bones of their prey" - Dr. Eric Snively, a post doctoral research fellow at the University of Alberta.

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