Worm

From Palaeos

At one time "worm" referred to any elongate creeping creature - it could just as easily indicate a snake or even a medieval dragon as an earthworm (Lambton was not terrorised by just any old nightcrawler...)

In the Systemma Naturae, Vermes became one of Linnaeus's six original classes, along with Quadrapeds, Aves, Amphibia (including reptiles) and Insecta, which made up the Animal kingdom. As such it was a wastebasket taxon for any species that didn't fit into any of the other five categories.

In zoology today, a worm simply refers to any generalised elongate limbless bilateral invertebrate. There are probably at least a dozen phyla, many totally unrelated, the members of which are referred to as "worms". Hence this is not a real taxon. Among the most familiar phyla of "worms" are Annelida (segmented worms - what most people think of as "worms"), Sipuncula ("peanut" worms), Nematoda (roundworms - actually a far larger group than annelids, but seemingly without the PR), Phoronida (no common name I'm aware of) and Priapulida (if there is a common name, we probably couldn't repeat it here).

Credits

MAK061106, enlarged CKT061106