“Giraffe neck dinosaurs” had a very special skeleton. The neck of the Tanystropheus hydroides was about as long as the body and tail combined. It is possible that more than 200 million years ago the animals lurked by the water for prey and then thrust their long neck into the water like a spear to eat. Conversely, experts have long suspected that the long, graceful neck also offered predators a good target. Now researchers put in the journal Current Biology two finds that clearly prove this for the first time. The analysis shows that both primeval reptiles examined were decapitated at the neck.
Stephan Spiekman and Eudald Mujal from the State Museum of Natural History in Stuttgart have examined two animals from different Tanystropheus species. The Tanystropheus hydroides measured up to six meters, the smaller Tanystropheus longobardicus was about one and a half meters long. Apart from the difference in size, both species, which probably lived mainly in water, were built similarly: they had 13 extremely elongated cervical vertebrae.
The examined fossils come from the Palaeontological Museum of the University of Zurich. In both cases, the otherwise extremely well preserved necks end abruptly. “Only the neck and head are preserved,” Mujal is quoted as saying in a statement from the magazine. “There is no sign of the rest of the animals. The necks end suddenly, which suggests that they were badly injured by another animal in an extremely violent event. This is also proven by the dental marks.”
Despite their vulnerability, long necks were apparently a recipe for success
In the larger specimen, the team actually found evidence of two bites on the tenth vertebra. When it snapped a second time, the attacker jerked its neck backwards – some of today’s reptiles act in a similar way. The attack was therefore from above or from behind. The smaller dinosaur was also bitten at least twice, with the fatal attack taking place on the seventh vertebra.
The authors write that the neck area of the seventh to tenth vertebrae is the most vulnerable part of these reptiles. “This region probably offered an optimal target for predators because it is far away from the head and in front of the thicker and more muscular neck,” it says.
The good condition of the neck and head shows that in both cases the attackers despised these parts of the body and probably clung to the fleshier rumps of their prey. In the case of the larger victim, the bite site with a distance of 1.5 centimeters between the teeth even allows conclusions to be drawn about the possible attacker: It could be the predatory lizard Nothosaurus giganteus, the fish dinosaur Cymbospondylus buchseri or the smaller Helveticosaurus zollingeri. In all of these cases, the attack would have taken place in the water.
In order to protect itself from such attackers, according to the author duo, Tanystropheus probably stayed in shallow waters with poor visibility and waited for prey there. Depending on its size, it fed on crabs, squid and fish. Members of this group have lived for at least ten million years and have thus been quite successful, despite their vulnerability. In general, long necks must have offered advantages, since they appeared in marine reptiles over a period of 175 million years.