mesozoan

[ mez-uh-zoh-uh n, mes-, mee-zuh-, -suh- ]
/ ˌmɛz əˈzoʊ ən, ˌmɛs-, ˌmi zə-, -sə- /
Zoology

noun

any member of the phylum Mesozoa.

adjective

of or relating to the mesozoans.

Origin of mesozoan

Scientific definitions for mesozoan

mesozoan
[ mĕz′ə-zōən ]

Any of a variety of very small parasitic marine animals of the group Mesozoa. Mesozoans resemble worms and have simple bodies divided into two layers. The outer layer is covered with cilia, and there are no internal organs. The taxonomic status of the Mesozoa is unclear, as some scientists believe the mesozoans to be an ancient and primitive group and others regard them as degenerate forms of more complex animals.