Neither shrimp nor vertebrate, Nectocaris pteryx was actually a type of mollusk.
It's not the mythical kraken, but an ancient creature belonging to the largest, nimblest and probably smartest group of invertebrates has jumped out of the fossil record with a different identity than previously thought. That finding restructures a branch on the evolutionary tree.
The tiny mysterious fossil of Nectocaris pteryx — previously described as a shrimp with a chordate tail — is neither a shrimp (an arthropod) nor a chordate (vertebrates and their nearest relatives), but a mollusk, according to a new study detailed in the May 27 issue of the journal Nature.
Don't picture boring mollusks, such as snails, slugs and mussels, however. Think cuttlefish, squid, and octopi — and yes, even the kraken — which are cephalopods, a member of the mollusk phylum. The 505 million-year-old creature is the oldest recorded cephalopod by about 10 to 15 million years and provides clues about modern cephalopod evolution.
Nectocaris is a miniscule cephalopod at only 2 to 3 inches (5 to 7 centimeters) long. It looks like a cartoon character from a Pixar movie with its bulging eyes and funnel-shaped nozzle that squirts water where one would expect a nose.