AncientOctus

AncientOctusses (Oudsignificare molluscus) are small mollusks that swim around using their large flaps on their tentacles to move around. They are the smallest, most ancient species of RocketSnail known. They are not considered RocketSnails, as they are not snails, yet are another kind of mollusk that evolved into many species such as the CartSnail.

Background
Back when Antarctica was much warmer, these creatures swam about off Antarctica's coast, using objects to create machines as large as elephants, of which the damaged fossils found cannot tell how they were used. AncientOcusses were wiped out by aquatic reptiles, and were eaten in vast groups. Their fossil records show very little evidence of contact with dry land.