Giant dinosaur had longest neck of any animal in history

Stretching for more than 15m, it was more than seven times longer than the neck of an adult giraffe.

Researchers believe that Mamenchisaurus sinocanadorum weighed about 19 tonnes and had a neck about 15m long.

Today’s tallest tale comes to you courtesy of Mamenchisaurus sinocanadorum.

A new analysis of the dinosaur’s fossilised bones suggests that when it walked the Earth about 160 million years ago it possessed the longest neck of any animal that has ever existed.

Stretching for more than 15m, it was more than seven times longer than the neck of an adult giraffe, or about 1½ times the length of a double-decker bus.

Mamenchisaurus, which is estimated to have weighed 19 tonnes, was one of the sauropod group of dinosaurs. Their long neck meant they could stand in one spot and graze on surrounding vegetation, conserving energy while eating tonnes of food.

This lifestyle proved to be exceptionally successful, with the sauropod lineage appearing early in dinosaur evolutionary history and persisting until the final days of the Mesozoic, when an asteroid strike wiped them out about 66 million years ago.

A long neck probably also ­allowed sauropods to shed excess body heat by increasing their surface area, much as the ears of elephants do today.

Working out the dimensions of sauropods is often not easy. For a skeleton to become a fossil, a creature must first be buried in sediment. The larger the animal, the less likely this is to happen. Poor preservation of sauropod specimens means estimates of their body size are often speculative.

This is true of Mamenchisaurus sinocanadorum, which is known only from a handful of bones from the neck and skull that were unearthed in northwestern China and first described in 1993.

In a new study published in the Journal of Systematic Palaeontology, researchers first mapped out its evolutionary links with more complete skeletons of other closely related species.

Using these relatives as a guide, they concluded that Mamenchisaurus sinocanadorum had a neck about 15.1m long, the longest of any known sauropod.

Andrew J. Moore, of Stony Brook University in New York state, who led the study, said: “All sauropods were big, but jaw-droppingly long necks didn’t evolve just once. Mamenchisaurids [the group to which Mamenchisaurus sinocanadorum belongs] are important because they pushed the limits on how long a neck can be and were the first lineage of sauropods to do so.”

The question of how sauropods managed to evolve such long necks and large bodies without collapsing under their own weight has puzzled scientists for decades. When studying Mamenchisaurus, Dr Moore and his colleagues, who included scientists from the Natural History Museum in London, were able to use CT scanning – a type of X-ray – to show that its neck bones were lightweight and largely hollow, with air spaces comprising as much as three quarters of their volume, similar to the lightly built skeletons of birds.

The Times