Sauropods are among the most spectacular dinosaurs that ever lived, thanks to their huge necks. In this group there is a species that stands out for its abnormally long neck even among sauropods: the Mamenchisaurus sinocanadorum, whose neck could measure as much as the rest of his body.
A group of scientists has carried out a new study on the dimensions that this prehistoric titan could reach, which raises new questions about how it could support its monstrous neck.
a jurassic giant
He Mamenchisaurus sinocanadorum It is the largest species of the genus Mamenchisaurus, a type of sauropod that lived in the late Jurassic in what is now China; and among all of them, it is the one with the longest neck compared to the body: this It could measure up to 15 metershalf the total length of the dinosaur.
“We really have no idea how this animal would have functioned mechanically,” says study lead author and dinosaur expert at London’s Natural History Museum, Paul Barrett. “It would take a lot of muscle to support a neck that size., and then there’s the question of how it circulated air into the lungs and back up again. This could support the theory that those necks were a sexually selected trait, since only the strongest dinosaurs could hold those giant necks and display them in order to mate.”
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Size comparison between the species of the genus Mamenchisaurus.
The secret of the huge necks of sauropods was in his vertebrae, which were elongated and very light, with air chambers inside like those of current birds. Their skulls were very small and light because they swallowed food without chewing it, so they did not need certain bones and muscles for chewing.
All this meant that the vertebrae had to support a comparatively low weight in relation to the size of the neck; In addition, they were surrounded by a structure of tendons and ligaments that distributed the stress they endured, resulting in a very flexible neck.
The new image of Mamenchisaurus sinocanadorum
So far only an incomplete skeleton of Mamenchisaurus sinocanadorum, made up of bones from the front of the neck, including part of the skull and a rib. The lack of a more complete skeleton made it difficult to get an idea of the real size of this dinosaur, until in 2012 a new species of giant sauropod called Xinjiang Titanclose relative of Mamenchisaurus, with a full neck. The study authors used this neck to recreate that of the sketchy dinosaur.
The secret of the huge necks of sauropods
The calculation was done comparing the ratio between the neck bones of the Xinjiang Titan. From the calculations a factor was obtained that was then applied to the partial skeleton of Mamenchisaurus. This was how it was possible to virtually reconstruct the approximate length of the latter’s neck, in addition to other characteristics of it.
Thus they deduced that these animals could have necks of up to 15 meters, which was approximately half the total length of the body. This characteristic is typical of the entire family of mamenchisaurids, among which is also the Xinjiang Titan.
In addition to the dilemma of how they mechanically supported such necks, another question is what they were needed for. Paul Barrett argues that they could have had several functions, including sexual display.
But their main reason seems to be related to their diet, although not in the way that is often assumed: rather than reaching the heights of the trees, the long and flexible necks of the sauropods allowed them to reach all the heights of the vegetation and also to reach the surrounding trees, which allowed them to access a lot of food from one place without having to constantly move. This reduced their energy consumption, something very important for animals that could gobble up half a ton of leaves a day, so they needed to eat a lot and fast.