Hallucigenia sparsa, (1:1) 2,5 cm.
The model was made in oversize and shrunk to achieve a high degree of details.
Supervised by Günter Bechly.
Hallucigenia is a textbook example of how difficult it can be to make sense of a fossil - sometimes it's hard to tell what an animal looks like when it's been extinct for over 400 million years. Scientists have studied the thumb-sized worm for more than 50 years now, and have only just discovered which end is the head. Hallucigenia have been reconstructed upside down and back to front several times. It is a 0.5–3.5 cm long tubular organism with seven or eight pairs of slender legs, each terminating with a pair of claws. Above each leg is a rigid conical spine.
It was not until 2015 that most scientist agreed on which end is the head - A new model for the creature includes a ring of teeth around its mouth, a simple pair of eyes, and a foregut lined with tiny little teeth.
Hallucigenia is now recognized as a "lobopodian worm". It is considered by some to represent an early ancestor of the living velvet worms, although other researchers favour a relationship closer to arthropods.