News:2009 sauropod neck study

In 2009, a paper published online in the journal Acta Paleontologica Polonica suggests that sauropods necks were held aloft.

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 suggested in their paper that sauropods could hold their necks low, but that it was not their "habitual posture".

ScienceDaily article
They studied X-rays of members of 10 different vertebrate groups and found that while the neck is only gently inclined in salamanders, turtles, lizards and crocodilians, it is vertical in mammals and birds – the only modern groups that share the upright leg posture of dinosaurs.

Dr Taylor said: “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.”

Modern vertebrates, from cats and humans to sauropods’ closest living relatives, the birds, hold their necks aloft in a vertical or near-vertical position.

Dr Wedel said: “We can’t just study fossil bones by themselves. Dinosaurs were living animals and to understand how they lived, we need to look at animals that are alive today. In this case, our evidence shows the present is the key to the past.”

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

Dr Taylor said: “Scientists have assumed that each pair of facets must maintain at least a 50 percent overlap at all times; but looking at what ostriches and giraffes do, we see that their facets can slide much further, until they hardly overlap at all. This means that 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.”

Low necked poses for sauropods have been used for countless plastic toys and have become part of mainstream culture, thanks in part to the BBC’s Walking with Dinosaurs, and to new museum exhibits such as one at the American Museum of Natural History in New York.

Professor Mike Benton at Bristol University’s Department of Earth Sciences, said: “It's hugely important to understand how sauropod dinosaurs functioned. They were so huge – ten times the size of an elephant – and yet they were successful animals. This new work provides plausible evidence that sauropods held their necks elevated, rather than horizontally, as had been assumed.

“The new work is based on studies of living animals, but the next step will be to carry out engineering studies to see whether the new or old neck positions are energetically more efficient. If you have a long neck that weighs a tonne or more you must hold it in a neutral position where stresses and strains are minimised.”