Branchiostomidae

Branchiostomidae
Branchiostoma lanceolotum
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Subphylum:	Cephalochordata
Class:
Order:	Amphioxiformes
Family:	Branchiostomidae

Branchiostomidae (syn: Branchiostomatidae) is the family that includes most of the lancelets, which are tiny chordates without a true spine but only a flexible .

Almost all lancelets belong to Branchiostoma, the one and only genus in the family Branchiostomidae. The genus was originally going to be called Amphioxus but was later changed to its current name.

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Wikipedia