Opabinia (ExtinctEgg #25)

Opabinia was a marine arthropod living in what is now modern-day Canada. It could grow up to 7cm (2.7 in) in length, and was an unusual-looking animal with a backwards-facing mouth under its head, a proboscis with a claw on the end to pass food to the mouth, and five eyes. Its appearance is so unusual that the audience laughed when its discovery was first presented to the public. It is closely related to radiodonts such as Anomalocaris, and shares a similar body plan to some extent, with a finned tail and flaps along its side. (Cambrian, 505 million years ago)