Encyclopedia > Hemichordata

  Article Content


Hemichordata is a phylum of deuterostome animals, generally considered the sister group of our own, the Chordates. They date back to the Lower or Middle Cambrian and include an important class of fossils called graptolites, which went extinct in the Carboniferous. Modern forms are marine worms, commonly called acorn worms. They are divided into two classes: the Enteropneusta[?] and the Pterobranchia[?].

All Wikipedia text is available under the terms of the GNU Free Documentation License

  Search Encyclopedia

Search over one million articles, find something about almost anything!
  Featured Article
French resistance

... unoccupied zone. They joined together to form maquis bands and began to plan attacks against the occupation forces. Some groups had also Spanish members who had fought in ...

This page was created in 40.1 ms