The genus "Plasmodium" was first described in 1885. At least ten species infect humans. Other species infect other animals, including birds, reptiles and rodents, while 29 species infect non-human primates. The Apicomplexa – the phylum to which "Plasmodium" belongs – are thought to have originated within the Dinoflagellates – a large group of photosynthetic protozoa.