Tully monsters haunted Earth’s oceans 300 million years ago and left behind such bizarre fossils that researchers haven’t even agreed on whether these strange creatures had backbones. Now, more than 60 years after the strange creature’s discovery in 1958, a new investigation using 3D lasers finds that the Tully monster was likely an invertebrate, but not everyone is convinced.

This alien-looking evolutionary oddball ​​— only found in the Mazon Creek fossil beds in Illinois — had a soft body, eyes on stalks, and a claw-like appendage coming out of its face. Other aspects of its anatomy, however, are open to interpretation.

The latest research, published April 16 in the journal Palaeontology(opens in new tab), is one of a slew of studies attempting to classify the creature.

more at livescience.com