Giant Dinosaur Had The Longest Neck Of Any Animal Ever Discovered

At 15 meters, its neck was six times longer than a giraffe's.


Rachael Funnell


Rachael Funnell

Digital Content Producer

Rachael is a writer and digital content producer at IFLScience with a Zoology degree from the University of Southampton, UK, and a nose for novelty animal stories.

Digital Content Producer

longest neck animal

Estimated to be 15 meters long, the neck of this Late Jurassic sauropod would be the longest we've ever identified in any animal species. Image credit: Júlia d Oliveira 

Giant giraffes walked the Jurassic in the form of long-necked Titanosaurs and Sauropods, but among them was one species to out-neck them all. A new fossil analysis has crowned the Chinese sauropod Mamenchisaurus sinocanadorum as the longest-known neck in the animal kingdom, stretching to a whopping 15.1 meters (49.5 feet).

The biggest dinosaurs aren’t always the easiest to study as they tend to get preserved in the fossil record as parts, rather than the whole animal. This means identifying the longest-necked sauropod has been tricky since most of the time researchers are working from a very incomplete puzzle.


Mamenchisaurus sinocanadorum is a good example, known only from a handful of bones from the neck and skull. However, by studying its family tree an international research team could use its evolutionary relationships to compare morphologies against skeletons and settle on the most likely body plan. Doing so led to the conclusion that M. sinocanadorum had a neck approximately 15.1 meters long.

It makes it the longest neck of any known sauropod, and possibly the longest of any animal ever to walk the Earth.

Mamenchisaurus sinocanadorum
Researchers only had a few fossils to work from, but were able to piece together the neck morphology of M. sinocanadorum by studying its evolutionary relationships. Image credit: Trustees of the Natural History Museum

“All sauropods were big, but jaw-droppingly long necks didn’t evolve just once,” said lead author and palaeontologist Dr Andrew J Moore of Stony Brook University in a statement sent to IFLScience.

Mamenchisaurids are important because they pushed the limits on how long a neck can be and were the first lineage of sauropods to do so. With a 15-metre-long neck, it looks like Mamenchisaurus sinocanadorum might be a record-holder – at least until something longer is discovered.”


With a neck longer than a double-decker bus, M. sinocanadorum would have been able to access resources that were out of reach to other species. Doing so helped them get big and strong, but holding up 15 meters of neck would have been almost impossible were it not for a nifty adaptation.

“Like all other sauropod dinosaurs, Mamenchisaurus had a complex breathing apparatus that included not only the lungs, but also numerous balloon-like air sacs,” explained Professor Paul Barrett, Merit Researcher at the Natural History Museum London, explains. “These were connected to the lungs and windpipe but spread throughout the interior of the animal’s neck, chest, and abdomen."

longest neck animal kingdom
The lower jaw and two of the vertebrae of Mamenchisaurus sinocanadorum linked together. Image credit: Trustees of the Natural History Museum

A memorable scene in Apple TV's Prehistoric Planet visualized these peculiar sacs, an adaptation that’s known as cervical pneumaticity. Effectively breathing into your bones would’ve made holding up giant necks easier, but it may have come with its downsides if these dinosaurs caught a common cold.

The longest neck doesn’t make for the biggest dinosaur, however. That title still belongs to the colossal titanosaur Patagotitan mayorum, a species about to go on display in the Natural History Museum London’s new exhibition, Titanosaur: Life As The Biggest Dinosaur.


We’ll have more on this in the coming weeks, so keep your peepers peeled. Something big is coming…

The study is published in the Journal of Systematic Palaeontology.


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