A worm-like creature called Hallucigenia because of its unusual appearance has earned a spot in the Tree of Life. This fossil, one of the most unique-looking ever discovered, is characterized by legs, spikes, and a head with a very similar appearance to its tail.

The creature has previously been considered an evolutionary misfit, due to a lack of indication over ways in which it relates to modern animal groups. Researchers from the University of Cambridge found a crucial link with modern velvet worms, or onychophorans, a generally small groups of worm-like creatures that live in tropical forests.

The research results are published in the journal Nature.

Lobopodians, a collective groups of contemporary ‘legged worms,’ such as Hallucigenia, is controversial as it does not have clear characteristics as there are no clear characteristics to help link the animals to each other or to modern animals, which has made it challenging to determine their evolutionary home.

The paper’s lead author, Dr. Martin Smith of the University’s Department of Earth Sciences, said in a statement, “It’s often thought that modern animal groups arose fully formed during the Cambrian Explosion.” He continued, “But evolution is a gradual process: today’s complex anatomies emerged step by step, one feature at a time. By deciphering ‘in-between’ fossils like Hallucigenia, we can determine how different animal groups built up their modern body plans.”

According to Berkeley.edu, Hallucigenia grew to lengths of just over an inch and is believed to scavenged the sea floor to find food.