Speciose:
(taxonomy) Rich in species, such as when many species are members of a single genus. [Wiktionary]
Noted on iNaturalist in their Birds of the World section:
In this vast world of ours there are over 10,000 species of Birds, which makes them the most speciose class of tetrapod vertebrates. This is what makes them so popular with bird watchers, along with there being so many different colors, shapes, sizes, sounds, behaviors, and ranges. With your help, together we can help the growth and knowledge of these amazing creatures! -John Fones
