They resemble bivalve molluscs but their shells develop on the dorsal and ventral surfaces rather than on the left and right surfaces of bivalves.
Even though this phylum develops as a protostome, it still shows radial cleavage and coelom development follows the pattern seen in deuterostomes. The genus Lingula under this phylum is likely the oldest surviving genus of animals. They contain a lophophore which is a ridge around their mouth; this trait relates them to phyla Phoronida and Ectoprocta. They resemble bivalve molluscs but their shells develop on the dorsal and ventral surfaces rather than on the left and right surfaces of bivalves. FTP name this phylum that dominated marine life in the Mesozoic and Paleozoic eras that contains lamp shells.
Even though this phylum develops as a protostome, it still shows radial cleavage and coelom development follows the pattern seen in deuterostomes.
brachiopoda