New York, Jan 6 (IANS): That a species of cockroach found only in text books has made an appearance after a 49-million-year hiatus can actually make the skin of the strongest man crawl!

Uprooting earlier theories, a shocking discovery has found the cockroach in the genus Ectobius back in motion.

It was the most common cockroach inhabiting a large region, from northernmost Europe to southernmost Africa till 49 million years ago.

Four ancient Ectobius species were recently discovered in the Green River formation near Rifle, Colorado, in deposits that are about five million years older than the Baltic amber (that itself is about 44 million years old).

“Nearly 65 years ago, several entomologists in the northeastern US noted that four species of Ectobius - known as Ectobius Kohlsi - were present in North America," said senior author Conrad Labandeira, curator of fossil arthropods at the Smithsonian's National Museum of Natural History in Washington.

“It was always assumed that these four newcomers were the first Ectobius species to have ever lived in North America. But the new discovery in Colorado proves that their relatives were here nearly 50 million years ago,” he added.

According to the study, the discovery also mirrors the biogeographic history of the horse.

Horses occurred in the New World and became extinct during the late Pleistocene (the Pleistocene epoch began about 1.8 million years ago and lasted untill about 11,700 years ago) ecological crisis.

Horses, attached to human habitation, were subsequently introduced to North America by early Spanish explorers about 11,000 years after their demise, said the study appeared in the journal Annals of the Entomological Society of America.

This particular species is named after David Kohls, who lives near Rifle in Colorado and has been a collector of fossil insects and plants from the nearby Green River Formation.