where did they get their name from?
It comes from the Greek word "koleopteros",  given to the group by Aristotle for their elytra, hardened shield-like forewings, from "koleos", sheath, and "pteron", wing.
Beetle
The name of the taxonomic order, Coleoptera, comes from the Greek "koleopteros" (κολεόπτερος), given to the group by Aristotle for their elytra, hardened shield-like forewings, from "koleos", sheath, an
how many species have been named in the order coleoptera 400,000 species. what is this species? They are insects.
wiki:1578807
Beetle [SEP] Etymology
The name of the taxonomic order, Coleoptera, comes from the Greek "koleopteros" (κολεόπτερος), given to the group by Aristotle for their elytra, hardened shield-like forewings, from "koleos", sheath, and "pteron", wing. The English name beetle comes from the Old English word "bitela", little biter, related to "bītan" (to bite), leading to Middle English "betylle". Another Old English name for beetle is "ċeafor", chafer, used in names such as cockchafer, from the Proto-Germanic *"kebrô" ("beetle"; compare German "Käfer", Dutch "kever").