Research suggests long-necked plesiosaurs fed on seabed
The long neck of the plesiosaur is a mysterious adaptation for which many hypotheses have been proposed. The most recent suggestion comes from Dr Leslie Noè of the University of Cambridge . After examining the neck vertebrae of the long-necked plesiosaur Muraenosaurus, whose name translates as ‘Moray eel lizard’, Dr Noè concluded that the natural position of the neck was a downwards curve towards the seabed. The ability of the neck to flex in other directions was more limited, and the swan-like pose often seen in restorations of plesiosaurs (pictured) was impossible.
It was also impossible for the plesiosaur to raise its neck out of the water in arc. The research was originally presented in 2004 at the 52nd Symposium of Vertebrate Palaeontology and Comparative Anatomy, Leicester, England, but was more recently presented this October (2006) at the 66th Annual meeting of the Society of Vertebrate Paleontology, in Ottawa, Canada). Incidentally, the findings have implications for the famous cryptid sometimes regarded as a plesiosaur, the Loch Ness Monster, since the inability for plesiosaurs to to raise their neck out of the water contrasts with reports of Nessie and conflicts with a plesiosaur identity for any monster living in the loch.
The plesiosaur neck may have been used to help the plesiosaurs head to sift through the sea bed for soft-bodied animals such as worms and soft small crustaceans. The idea is backed up the recent discovery of fossil stomach contents in a plesiosaur, which contains sea-shells. However, although the idea is appealing, Dr Noè states (personal communication) that this is probably only part of the story concerning the function of the long neck in plesiosaurs.