Hemichordata, also known as cryptozoans, are some marine taxa that have a short blind tube on the back of the mouth that extends into the snout. Pty-choderaflava was first discovered and named in 1825. At least more than 90 species have been discovered around the world, including the worm-like Enterobranchia and the bryozoan-like Pintlebranchia. Among them are More than 77% of the species belong to the Enterobranchia class, and the most common representative animals are various acorn worms.