What classification are Platyhelminthes under? What is its classification under?
- Platyhelminthes are classified under the Turbellaria. Turbellaria's are free living creatures. This means they can be found wandering anywhere in the general environment. You can find these creatures crawling around mostly on surfaces at the bottoms of bodies of water. The subgroups within this subgroup are divided mostly based upon how their digestive cavities are constructed.
- The Trematodes are a group of parasites. There are three subgroups within this subgroup. Two of them have relatively minor effects on the world. One is a parasite mostly on the outside of fish, the other found mostly inside mollusks such as snails! The Digenea, which is the their subgroup, includes a number of serious parasites of humans and other large animals.
- The Cestodes, or tapeworms, are also parasites. In their adult forms, these worms are attached with a specialized "head" called a Scolex, to the lining of their hosts' intestines and begin to lengthen, and start to reproduce.
What group did it evolve from? When did Platyhelminthes come into existence?
Some say jellyfish seem to have evolved into various different kinds of worms, one of which was the ancestor of flatworms. Then they too, probably evolved into higher animals. Ancestral flatworms may have first appeared around 570 million years ago.