Although originally described in 1877 as a class , and sometimes characterized as an order of the phylum Mesozoa , recent study shows that orthonectids are quite different from the rhombozoans , the other group in Mesozoa .
The orthonectids were originally described in 1877 as a class , and placed as an order of the phylum Mesozoa . Recent study shows that orthonectids are quite different from the rhombozoans , the other group in Mesozoa .