Big dinosaurs carried their heads high, say scientists

Published on Tuesday 26 May 2009 19:02

THE largest dinosaurs held their heads up high and not out in front of them as depicted by top museums around the world, according to new research published today.

Sauropods, which were up to 30 metres (98ft) long and weighed as much as ten elephants, have been traditionally depicted as holding their very long necks and small heads horizontally in front of the body.

But Dr Mike Taylor and Dr Darren Naish, of the University of Portsmouth, and Dr Matt Wedel, of Western University of Health Sciences in California, have found this was not the creature's habitual pose.

After examining long-necked animals such as giraffes and ostriches, they say it would be natural for the sauropod to hold its neck and head upwards. This goes against how sauropod skeletons are presented at museums and onscreen.

Low-necked poses for sauropods were used in BBC's Walking with Dinosaurs and are common for plastic toys and museum exhibits such as one at the American Museum of Natural History in New York.

Dr Taylor said they studied X-rays of ten different groups of animals and found that the neck was only gently inclined in salamanders, turtles, lizards and crocodiles.

It was vertical for mammals and birds, which are the only modern groups that share the upright leg posture of dinosaurs, Dr Taylor said.

He added: "Like the animals we have with us today, they would have spent most of their time with their necks elevated, except when drinking or browsing at low levels."

Dr Taylor explained the neck vertebrae of sauropods fit together mainly by way of ball and socket joints. In addition, the top part of each vertebrae has a pair of facets, two at the front and two at the back, which glide past each other when the neck bends.

He added:

"Sauropods would have had a far greater range of neck movement than has been thought in recent times.

"Unless sauropods carried their heads and necks differently from every living vertebrate, we have to assume that the base of their neck was curved strongly upwards.

"In some sauropods this would have meant a graceful swan-like S-curve to the neck, and a look quite different from the recreations we are used to seeing today."

However, Dr Paul Barrett, dinosaur researcher at the Natural History Museum, said he believed the new research was not conclusive and there was evidence that sauropods did hold their necks horizontally.

He said: "The idea that sauropod dinosaurs held their necks upright is not a new idea.

"It is not unreasonable to suggest that their necks may have been held in a vertical position for some of the time, but sauropod lifestyles would have required necks with a wide range of movement, not least to reach down to drink water from ground level, as well as being able to move the neck from side to side.

"There is no scientific justification for changing the sauropod mounts in our galleries: these positions definitely reflect at least some of the poses that sauropods would have been able to adopt in life."