The smallest mammoth known to have ever existed has been identified by scientists.
Mammuthus creticus, was roughly the size of a modern baby African or Asian elephant, standing a little over a metre tall at the shoulders, and may have roamed Crete as early as 3.5 million years ago.
M. creticus has been identified by re-examining fossil teeth in the Natural History Museum collection that were originally collected by legendary fossil hunter Dorothea Bate in 1904.
The research team also retraced Bate’s footsteps on Crete to find new fossil evidence that enabled them to reconstruct the size of the dwarf mammoth.
"Dwarfism is a well-known evolutionary response of large mammals to island environments," explained palaeontologist and lead researcher Dr Victoria Herridge.
"Our findings show that on Crete, island dwarfism occurred to an extreme degree, producing the smallest mammoth known so far.
"As such we can show that this extreme insular evolution has taken place independently in two different non-dwarf elephant lineages the straight-tusked elephants, Palaeoloxodon, and mammoths, Mammuthus. This opens up the possibility that dwarf mammoths evolved on Crete much earlier than we previously thought, perhaps as early as 3.5 million years ago."
The fossil teeth were originally thought to be dwarf forms of the straight-tusked elephant Palaeoloxodon antiquus, which is considered the evolutionary ancestor of all dwarf elephants.
But the new study in today’s Proceedings of the Royal Society B shows they are part of an entirely different group of extinct elephants: the mammoths.
Bate’s specimens share several key physical traits with mammoths linked to the shape of the enamel on the surface of the molar tooth. Tooth shape characteristics such as the height of the tooth relative to its width suggest that M. creticus was most closely related to, and probably descended from, either M. meridionalis which roamed the plains of Europe 2.5 million to 800,000 years ago or the even earlier M. rumanus, meaning the smallest mammoth could have reached Crete as long ago as 3.5 million years ago.
"We’ve tended to think of the really tiny Mediterranean dwarf elephants as having descended from the straight-tusked elephant.
"Using the Museum’s collections alongside new measurements of an upper arm bone we found when we went back to Crete we now know that Bate’s specimens are mammoths with similarities to both M. meridionalis and M. rumanus.
"The arm bone in particular gives us the best evidence so far for how big – or rather, how small – this dwarf mammoth really was" said Herridge.