Cambridge University researchers have discovered the fossils of a bizarre worm-like animal that lived 505 million years ago -- a weird legged worm called Haalucignia. The creature has been linked with a group of modern animals for the first time. These particular fossils come from the Burgess Shale in Canada's Rocky Mountains, one of the richest Cambrian fossil deposits in the world.

Hallucigenia had a row of rigid spines along its back, and seven or eight pairs of legs ending in claws. The animals were between 0.2 and 1.4 inches (five and 35 millimeters) in length, and lived on the floor of the Cambrian oceans.

The discovery was published in the journal Nature by scientists at the University of Cambridge. It had once been considered an 'evolutionary misfit' as their discovered fossils of 1970 gave them a hard time to figure out what they were looking at. Their physical characteristics didn't give them a clear view to find their evolutionary home. But now scientists say that the studies of Haalucignia's claws revealed an association very close to those of modern velvet worms that live in tropical forest.

The spines along the creature's back were originally thought to be legs; its legs were thought to be tentacles along its back, and its head was mistaken for its tail.

Dr. Martin Smith, a scientist in the university's department of earth sciences and the lead author of a paper added that the new research has unveiled another peculiar species the humans were not aware of. Dr. Smith describes Hallucigenia's claws as the "smoking gun", with layers of cuticle stacked together like Russian nesting dolls.

Study co-author Dr. Javier Ortega-Hernandez, in a statement, said, "An exciting outcome of this study is that it turns our current understanding of the evolutionary tree of arthropods--the group including spiders, insects, and crustaceans--upside down".

Dr. Smith believes that determining in-between fossils can help scientists figure out different animal groups that have now evolved into their modern-day forms.