Glossary of Morphological and Anatomical Terms
gastrothyrid - Pedicle opening limited to ventral valve.
geniculate - Abrupt and more or less persistent change in direction of valve growth producing angular to sharply rounded bend in lateral profile.Fig.287.
geniculated spines - Chonetid hinge spines commonly cyrtomorph bending along their length.
genital area - Part of shell known to be or inferred to have been overlain by gonocoel.
genital markings - Radial ridges or pits on inside of shell within genital area.
ginglymus - Secondarily developed, heavily thickened hinge line especially characteristic of ventral valves of some productides, externally resembling interarea.
glossothyropsiform - Long reflected loop unsupported by median septum bearing two broad ascending elements joined by wide transverse band.
growth line - Concentric line on outer surface of shell formed when forward growth of shell temporarily ceased.Fig.290,Fig.291,Fig.294.
gusset - Plate uniting brachiophore to cardinal process shaft of orthotetidines; homologue of inner hinge plate.
