Phylum Mesozoa
Mesozoa is one of those phyla that scientists don’t know how to classify. Many use it as a group or clade and put 2 mesozoan phyla in it. Others classify them in a phylum. Still, others group them in a subphylum in the phylum Platyhelminthes. Also, scientists don’t really know how closely related to other phyla. So, scientists are still arguing about where this phylum, subphylum, or group should be. Mesozoans are basically very tiny worm-like animals that are parasites. Their bodies are made up of a couple of reproductive cells which are surrounded by a layer of cells. Mesozoans now are divided into two phyla: Dicyemida and Orthonectida. Phylum Dicyemida contains the Rhombozoans, and Orthonectida contains the Orthonectid mesozoans. However, there is another questionable phylum called Monoblastozoa, which possibly contains one species, which has been seen only once in all of recorded history. For this reason, many scientists don’t agree with this new phylum, which is why in this book, I will have only 2 phyla or subphyla. Although mesozoans are related, there are a few difference between the 2 phyla. Rhomobozoans are tiny creatures made up of just a few cells, which can reproduce asexually or sexually. They are found in the nephridium, a kidney-like organ, of octopi and squid. Orthonectids are parasites of brittle stars. Scientists don’t know much more than that about mesozoans.
Symmetry: Bilateral?
Species Number: ?
Classification:
Kingdom Animalia
Eumetazoa?
Bilateria?
Mesozoa
Phylum Dicyemida
Class? (3 families)
Phylum Orthonectida
Class? (2 families)
Symmetry: Bilateral?
Species Number: ?
Classification:
Kingdom Animalia
Eumetazoa?
Bilateria?
Mesozoa
Phylum Dicyemida
Class? (3 families)
Phylum Orthonectida
Class? (2 families)