Meat-eating dinosaurs usually star in films for their big teeth and nasty dining habits, but some of the carnivores were more likely softies, providing a nanny service for the babies and sitters for the young.
The personality type depended on the meat eater involved, explained Dr Theagarten Lingham Soliar of the Russian Academy of Sciences, who yesterday spoke at the British Association for the Advancement of Science festival.
Tyrannosaurus Rex was a lone hunter with plenty of "firepower" for finding, catching and devouring prey. And while there was no evidence yet to prove that the Velociraptor was a true pack hunter, there were indications that the smaller desert dweller, Syntarsis, lived in groups, protected nest sites and used "nurseries" to keep an eye on the kids. Scientists who studied dinosaurs had suffered criticism in the past as doing little more than "telling stories" he said, proposing theories without any evidence to back up assumptions about dinosaur behaviour. Palaeontologists were currently riding high thanks to the two Spielberg films, but care was required to protect the quality of their science from insubstantial theories.
Dr Lingham-Soliar dismissed notions that tyrannosaurs were either scavengers or fed by "ramming" their prey. Ramming predators invariably had tough often bony projections that protected their precious teeth, and T-Rex lacked such a structure.
"If you lose your teeth, that is your bread and butter if you are a carnivore." The size and power of the large head, jaws and neck also made scavenger subsistence unlikely. "This really doesn't bear thinking about. He is an animal with real fire power, this was certainly not a scavenger." He argued that tyrannosaurs were "shake feeders", using jaws and neck muscles to shake apart prey in the same method used by dogs, crocodiles and killer whales.
"Were tyrannosaurs gregarious?" he asked. Some palaeontologists said yes but the evidence left behind in preserved dinosaur footprints did not support the claim. Footprints of the large meat eaters were usually found in solitary tracks.
"The big carnivores were lone hunters, they had the firepower to do it and the footprints consistently show single tracks of individuals" which covered a wide feeding area. The much smaller carnivores, Deinonychus and Velociraptor, on the other hand were "very much like predatory birds", Dr Lingham-Soliar suggested. "Clearly they were superb predators but one of the key questions was whether Velociraptor was a pack hunter."
