Scientific name Branchiostoma
Higher classification Branchiostomidae
|Lower classifications Branchiostoma lanceolatum, Branchiostoma floridae|
These small vaguely eel- or snake-like animals are close relatives of vertebrates. The scientific name means "gill-mouth", referring to their anatomy – unlike vertebrates, they do not have a true head (with a skull capsule, eyes, nose, a well-developed brain etc.), but merely a mouth adjacent to the gill-slits, with the slightly enlarged anterior end of the dorsal nerve cord above and in front of them.
Lancelet biodiversity is not very well studied; other as yet undescribed species (perhaps including cryptic species) might await discovery.