Acanthocephala

Part of speech: noun

Definitions

1. A phylum of parasitic worms characterized by spiny heads and a lack of a digestive system that attach to hosts' intestines
2. A group of endoparasitic organisms known for their segmented bodies and unique hooks for anchoring within their hosts
3. A class of invertebrates distinguished by their complex life cycles and reliance on intermediate hosts for development and reproduction

Etymology: Acanthocephala is a phylum of parasitic worms, and its name was coined in the 19th century from ancient Greek roots rather than inherited from antiquity. "Akantha" means "thorn" or "spine," and "kephale" means "head," so the name means "thorny-headed." The reference is to the retractable proboscis that these worms use to hook into the intestinal wall of their hosts, which is covered in rows of backward-curving spines. The Greek elements were assembled by scientists, not by the ancient writers who first used "akantha" and "kephale" for thorns and heads in everyday or poetic contexts. The group was given its modern name by zoologists working in Europe in the 1800s, who needed a descriptive label for a body plan that had no ancient counterpart. Because the name was built from familiar classical parts, it reads as ancient even though it is a recent creation.

Synonyms: thorny-headed worms, spiny-headed worms