Hemichordates, the worm like marine organisms is usually considered as a subphylum of the phylum Chordata (Bateson, 1885) but in
recent times it closely related to the Echinodermata’s and
considered as a separate phylum among invertebrates (Hyman, 1959).Current status refers it as a sister group of Echinodermata(Lowe and Gerhart, 2004).
Protozoa, a single celled, acellular, and eukaryotic organism along with other single cell algae and slime molds comes under Kingdom
Protista as they posses much simpler structures than the members of the Kingdom Animalia (Seppo & Sven, 2019)
In modern times subphylum Onychophora of the phylum Arthropoda is considered as an independent minor phylum having 200 known species (Shrock, 1958)
References:-
Lowe C.J. and Gerhart J. (2004): Hemichordate Embryos: Procurement, Culture and Basic methods, Methods in cell Biology, 74: 171-194.
Seppo, SDVM and Sven NDVM (2019): Protozoa, Canine parasites & Parasitic Diseases, Science Direct, 5-34
