This raises the possibility these groups were segregated by age.īy looking at all areas of how the dinosaurs died, the team concluded that although many ankylosaurs may well have led solitary lives, at least some species gathered into groups at certain times in their life. The MDAs of the USA contained small groups of adult Gastonia, whilst the Hungarian MDA was also made up of mature ankylosaurs. The Mongolian MDA consisted of juvenile individuals of one species, Pinacosaurus, indicating that young animals were gathering together, possibly for protection. In addition to the fossils, the team also studied how modern large herbivores live and socialise. They looked specifically at the age of the individuals buried at each site, their armour and body plan and the types of habitat they died in. The team studied the fossils from six ankylosaur MDAs found in the Cretaceous rocks of the USA, Hungary and Mongolia (145 to 66 million years ago). This indicates that at least for heavily armoured adult ankylosaurs, the animals were capable of fending off predators on their own.īut the remains of ankylosaurs have also been found in Mass Death Assemblages. This solitary lifestyle is supported by the fact that the dinosaurs were covered in extensive body armour that was probably used in part for defence. Their tank-like bodies and short legs were likely inefficient for long-distance walking in herds suggesting that they lived a solitary lifestyle with a limited home range, similar to that of modern-day rhinoceros. Typically, ankylosaur fossils are found as individual specimens.

If these bones are all from dinosaurs of the same species, it's possible they all died around the same time and so were perhaps living together as a herd.Ī team led by Gábor Botfalvai have recently published a paper investigating the evidence for social structures amongst one particular group of dinosaurs: the armoured, plant-eating ankylosaurs. These are sites where the bones of large numbers of dinosaurs are found in a single location and can contain the remains of thousands of individuals. Whether dinosaurs maintained their social distance or moved in herds has long been an area of debate.Įvidence for herding behaviour in large herbivorous dinosaurs has previously been found in the form of trackways and something known as Mass Death Assemblages (MDAs). Fossil bones are great for telling us how ancient animals looked, but not how they behaved.

Ankylosaurus walking with dinosaurs