. Bulletin of the British Museum (Natural History), Geology. 44 THE BRACHIOPOD SUBFAMILY although investigation of the Hauterivian genus Belothyris, carried out here, throws Hght on an alternative evolutionary trend and a possible link with Lower Albian species now considered to belong to the genus Kingena. There are still many gaps in our knowledge of these forms and more research is needed before any hard and fast conclusions can be reached as to their lineage. The internal characters of both Zittelina and Kingena are broadly discussed and compared here. Both genera have similar cardinalia,
. Bulletin of the British Museum (Natural History), Geology. 44 THE BRACHIOPOD SUBFAMILY although investigation of the Hauterivian genus Belothyris, carried out here, throws Hght on an alternative evolutionary trend and a possible link with Lower Albian species now considered to belong to the genus Kingena. There are still many gaps in our knowledge of these forms and more research is needed before any hard and fast conclusions can be reached as to their lineage. The internal characters of both Zittelina and Kingena are broadly discussed and compared here. Both genera have similar cardinalia, consisting of a very small cardinal process, with deep concave hinge-trough supported by long, high median septum. The descending branches of the brachial loop, originating from the distal ends of the hinge-trough, extend anteriorly, developing long crural processes. Attachment of the descending branches to the septum is by means of two broad bands, one from either branch, which curve inwards towards the septum and then upwards and Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original British Museum (Natural History). London : BM(NH)
Size: 1658px × 1508px
Photo credit: © Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorbritishmuseumnaturalhistory, bookcentury1900, bookcoll
