Answer:
Parasites fit under my classification
Right now, there are about 60,000 to 200,000 species that classify as me, a Protist.
One-half of the oxygen on the planet comes from me.
Though I'm a Taxonomic Classification, I do have a lot of things that classify as me
Invertebrates are also under my classification
Some examples of me include: amoebas (including nucleariids and Foraminifera); choanaflagellates; ciliates; diatoms; dinoflagellates; Giardia; Plasmodium (which causes malaria); oomycetes (including Phytophthora, the cause of the Great Famine of Ireland); and slime molds.
The three main categories I can be classified into are Animal-like protists, plant-like protists, and fungus-like protists.