Hemichordata
Nota de aplicación
Small phylum that includes acorn worms and pterobranchs, characterized as wormlike marine invertebrates closely related to the chordates. While they are typically given phylum rank, some sources place the group at various other taxonomic levels with the other so-called protochordates. Hemichordates are so named for the Greek hemi, meaning "half," and chorde, meaning "string," thus, "half-chordate," which was first proposed because the buccal dive…