; order Amphioxiformes)
A family of small, fish-like, marine, coastal animals. Lancelets are the only living representatives of the subphylum Cephalochordata. Although definitely not true fish, lancelets (e.g. Branchiostoma lanceolata) are considered fairly close to the vertebrate ancestral lineage. They have an almost transparent body, no eyes or brains, a permanent notochord extending into the head and a dorsal hollow nerve cord, gill slits, and segmented muscle blocks. They spend most of their lives buried in the sediments beneath the world's oceans.
Subjects: Zoology and Animal Sciences.