After 50 years, scientists discover head of the insane Hallucigenia 'worm'
Teeth in weird places
By Arielle Duhaime-Ross on June 24, 2015 01:00 pm
Sometimes it's hard to tell what an animal looks like when it's been extinct for over 400 million years — just ask Hallucigenia. Scientists have studied the thumb-sized worm for more than 50 years now, and have only just discovered which end is the head.