Mini-hedgehog fossil discovered
If Beatrix Potter wrote fairy tales she might have dreamed up Silvacola, a prehistoric hedgehog just two inches long.
Like Thumbalina, the tiny girl in the Hans Christian Andersen story, the creature was about the size of an adult thumb.
Silvacola, which lived 52 million years ago, was completely unknown to science before its fossil remains were discovered at a nature park in British Columbia, Canada.
Professor Jaelyn Eberle, from the University of Colorado, US, who led the team that made the find, said: "It is quite tiny and comparable in size to some of today's shrews."
The mini-hedgehog may or may not have had a prickly back, like Potter's Mrs Tiggywinkle.
"We can't say for sure," said Prof Eberle. "But there are ancestral hedgehogs living in Europe about the same time that had bristly hair covering them, so it is plausible Silvacola did too."
The fossil bones were found at a site in Driftwood Canyon Provincial Park, British Columbia, that was a rainforest during the early Eocene epoch when Silvacola was alive. Its full name, Silvacola acares, means "tiny forest dweller".
Scientists employed an unusual technique to ensure the hedgehog's delicate jaw was not damaged by removing it from the surrounding rock.
An industrial CT (computed tomography) scanner was used to capture 3D X-ray images allowing the creature's tiny teeth to be studied safely.
Modern hedgehogs and their relatives are restricted to Europe, Asia and Africa and not found in the New World.
The early Eocene, one of the warmest periods on Earth since the extinction of the dinosaurs 66 million years ago, produced a community of mammals in North America quite different from those living today.
Most of the fossil-bearing rocks at Driftwood Canyon formed at the bottom of an ancient lake, and are renowned for their well-preserved leaves, insects and fishes.
However, until now, no mammal fossils had ever been found at the site.
Alongside Silvacola, scientists also discovered the remains of a tapir-like animal about as big as a dog.
Heptodon was half the size of modern tapirs and lacked their distinctive short trunk.
"The discovery in northern British Columbia of an early cousin to tapirs is intriguing because today's tapirs live in the tropics," said Dr Eberle.
Professor David Greenwood, from Brandon University in Manitoba, Canada, a co-author of the research published in the Journal of Vertebrate Paleontology, said: "Driftwood Canyon is a window in to a lost world, an evolutionary experiment where palms grew beneath spruce trees and the insects included a mixture of Canadian and Australian species.
"The early Eocene is a time in the geological past that helps us understand how present-day Canada came to have the temperate plants and animals it has today. However, it can also help us to understand how the world may change as the global climate continues to warm."