Almost all lancelets belong to " Branchiostoma ", the one and only genus in the family Branchiostomidae.
2.
The lancelet " Branchiostoma lanceolatum ", the nearest existing relative to vertebrates, also lacks a recognizable pineal gland.
3.
They suggested that the vertebrate head is a new structure, which has no corresponding structure in close relatives such as Branchiostoma.
4.
A T-box-containing cDNA was isolated in the lancelet " Branchiostoma belcheri " and found to possess a T-domain orthologous to that of the T-Brain subfamily of T-box genes, specifically TBR1.
5.
The cephalochordate Branchiostoma ( formerly called Amphioxus ), which is the closest relative of vertebrates, is a burrowing marine creature which lacks most of the head structures that are so distinct in vertebrates, such as distinct sense organs; a large, multilobed brain; teeth; and a tongue.
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