Pretensions attended a Science in the Cafe discussion on dinosaurs at the Singapore Science Centre on Thursday night, simply because, hey, everyone loves dinosaurs! The talk was held in Hall C of the Science Centre, so the audience was surrounded by moving animatronic dinosaurs, which added considerably to the atmosphere. However, technical difficulties with turning off the sound led to the odd crescendo of roaring during the talk - which made some parts very hard to catch, especially since the speaker, Japanese scientist Dr Makoto Manabe, was quite soft-spoken.

Makoto Manabe is currently a senior scientist and senior curator of vertebrate palaeontology at the National Museum of Tokyo. He has been in the news recently for excavating a giant ichthyosaur skeleton in British Columbia. Makoto gave a wide-ranging and interesting talk on the latest research findings on the lives of dinosaurs. P was just a little cheesed off with a plump precocious 12-year old in the audience that kept interrupting the talk with incoherent statements (not questions but statements) on his insights on dinosaur research - she spent some time wishing for a Night in the Museum segment where the reanimated T-Rex skeleton would reach down and bite his head off.

 

Various Animatronic Dinosaurs in the Science Centre exhibition hall

Run, T-Rex, Run!

Contrary to the popularly imagined ideal of T Rex romping happily around the prehistoric plains and running down a Triceratops o r two, biomechanicians now believe that T Rex was way too slow and top heavy (with its huge skull and teeth) to manage this kind of lifestyle. Models of bone structure and muscle have come up with two different answers, a maximum possible sprinting speed of 40-50 km per hour and a safe sprinting speed of only 11-12 km per hour (Jurassic Park was highly exaggerated).

What is a "safe" sprinting speed? Well, T-Rex was a 6000+ kilogram animal with most of that mass going into its massive jaws, counterbalanced by sturdy legs and a muscular tail.  T-Rex could only run if its legs were held relatively straight, keeping its center of mass stable above its knees. But if T-Rex tripped over a boulder or something, its massive heavy head would ensure that the dinosaur's chin would hit the ground with bruising force, possibly causing severe damage to its tiny brain and other soft tissue. This meant that T-Rex had to go slow to be safe.

New fossil evidence has also shown T-Rex sunk in a crouch on the ground. Models based on this show T-Rex in a crouched resting posture, levering itself forward on its legs and then pushing off with its tiny arms to finally come to an upright position. Dr. Makoto said that one new model for T-Rex behaviour might have been that the dino was an ambush predator, staying crouched and still most of the time and rousing itself for a short sprint when unwary prey came nearby. P thinks this sounds quite reasonable when compared to the behaviour of modern crocodiles and alligators. That massive head would then have been a real advantage as the dinosaur leapt in for the kill, bringing all that weight to bear on the poor victim's throat.

It could even have been a scavenger, waiting for smaller speedier dinosaurs to kill before chasing them off and securing the prey carcass for itself. Here is a link to a HowStuffWorks video on the whole T-Rex behaviour question (you have to sit through the adverts first).

It's a bird, it's a....dinosaur?

The other topic Dr Manabe covered was the dinosaur-bird relationship. Most readers will have heard that birds are the most direct descendents from dinosaurs. Relatively few DNA mutations are required to convert scales to feathers and the conversion may have happened several times in several lines of dinosaurs. The most well-known of the feathered dinosaurs is Archaeopteryx. On the left is one of the latest images of Archaeopteryx, the gliding dinosaur.

In 2000, scientists in China found what may be a related dinosaur called Microraptor, which had four wings - two large ones on its forelimbs and two shorter ones on its legs. It is thought that Microraptor might have climbed trees and jumped off high branches to glide between trees, the way flying squirrels do today. The little dinosaur was only 39 cm tall, of which 24 cm was tail.

New fossil evidence has shown that that evil star of Jurassic Park, Velociraptor, might also have been feathered. A fossil was found showing quill knobs on the forelimb bones of a Velociraptor specimen, but it is not known whether the feathers were functional or only for display.

Below find an artist's rendition of Velociraptor with feathers and with bare skin. Still not exactly cuddly.