Dinosaurs had an advanced ability to hear which gave their just-hatched offspring a chance to avoid being squashed by their parents, a new study has revealed.
The study by German and Austrian scientists from Greifswald and Vienna universities looked at fossils of the herbivore Europasaurus holgeri, a dwarf relative of the giant Brachiosaurus.
Both were long-necked quadrupeds but unlike the Brachiosaurus, which could be up to 15 metres tall, the European-based Europasaurus holgeri was usually just three metres high.
It lived some 154 million years ago and the study of the skulls from specimens of different ages found in Lower Saxony at a single site has produced a fascinating insight into its probable habitats.
Research on the fossil’s inner ear reveals that both the young and adults had similarly advanced hearing.
In a statement obtained by Newsflash Marco Schade from the University of Greifswald Institute of Geography and Geology said the published results give an impression of the evolutionary history of long-gone biodiversity at a time long before humans entered the scene.
He said: “The part of the inner ear that is responsible for hearing, the lagena or cochlea, turns out to be relatively long in Europasaurus.
“This circumstance suggests that these animals had a good sense of hearing, rendering intraspecific communication crucial and gregarious behaviour likely.
“Another part of the inner ear is relevant for the sense of equilibrium and consists of three tiny arches.”
He said the fact that the inner ear cavities within very small specimens resemble the respective cavities of adults in form and size suggests that Europasaurus strongly relied on its ability to balance from a very young age.
He added: Some considered skull remains were so tiny (~2 cm) that they may belong to hatchlings, rendering the species precocial.
“Whereas some sauropods weighed in at several tens of tons more than their newly-hatched offspring (posing a lethal threat for the latter), the hatchlings of Europasaurus may have immediately roamed together with the herd.”
Sebastian Stumpf from the University of Vienna noted: “Precocial animals are those in which even the youngest members of their species move relatively independently. They don’t just ‘squat in the nest’ but leave it early.”
He said that the other sauropods in the group would have been a few tons heavier than their freshly hatched offspring and thus posed a life-threatening risk.
That makes it likely that the Europasaurus hatchlings would have quickly fled the nest to avoid getting trampled underfoot.
Because of the large size of the adults, they were unable to do much for the young and had to look after themselves from the start.