PhysOrg explains that they were really Elasmotheriums – 3.5-ton primordial rhinos known as “Siberian unicorns” – but they really did survive into the era of modern humans, until climate change doomed them:
An international team of researchers from Adelaide, Sydney, London, the Netherlands, and Russia, have settled a long-standing debate about the relationship of the Siberian unicorn to living rhinos, and revealed that it survived much later than previously believed, overlapping in time with modern humans.
Published in the journal Nature Ecology and Evolution and led by London’s Natural History Museum, the researchers say the Siberian unicorn became extinct around 36,000 years ago. This was most likely because of reduction in steppe grassland where it lived – due to climate change rather than the impact of humans.
Genetic analyses performed at the University of Adelaide’s Australian Centre for Ancient DNA (ACAD), however, have shown that the Siberian unicorn was the last surviving member of a unique family of rhinos.
“The ancestors of the Siberian unicorn split from the ancestors of all living rhinos over 40 million years ago,” says co-author and ACAD researcher Dr. Kieren Mitchell, who analysed the DNA of the Siberian unicorn. It is the first time DNA has ever been recovered from E. sibiricum.
In this study 23 Siberian unicorn bone specimens were dated, confirming that the species survived until at least 39,000 years ago, and possibly as late as 35,000 years ago. The Siberian unicorn’s final days were shared with early modern humans and Neanderthals.
“It is unlikely that the presence of humans was the cause of extinction,” says co-author Professor Chris Turney, climate scientist at the University of New South Wales.
“The Siberian unicorn appears to have been badly hit by the start of the ice age in Eurasia when a precipitous fall in temperature led to an increase in the amount of frozen ground, reducing the tough, dry grasses it lived on and impacting populations over a vast region.”