Gwynia capsula (Jeffreys), an Articulate Brachiopod with Brood Protection

Abstract

THE articulate brachiopod Gwynia capsula (Fig. 1), which is only about 1 mm in diameter, was described by Jeffreys in 1859 and recorded during the last half of the nineteenth century from several marine localities in Great Britain, as well as from the continental side of the Channel. Because of the very small size of the animal, it was suggested that it might be the juvenile stage of some larger known species¹. In spite of older records^1,2 the species is not listed in the Plymouth Marine Fauna³ and it is quoted as a doubtful species in modern text-books^4,5. According to the description^6,7, Gwynia capsula has some morphological details which are interesting from the point of view of brachiopod phylogeny. One of these features is the lophophore, which represents the simplest (trocholophous) type. A revision of the morphology of Gwynia capsula is now in progress in this laboratory.