Fig. 16. A, B in Silicified Mississippian brachiopods from Muhua, southern China: Lingulids, craniids, strophomenids, productids, orthotetids, and orthids

Fig. 16. A, B. Two hypothetical mode of attachment of juvenile Argentiproductus margaritaceus (Phillips, 1836). The extent of attachment (here marked with white areas) by the epithelium emerging through longitudinal median slit in the umbonal region of the ventral valve (A) seems more probable and functionally efficient than the attachment by the tip of a cylindrical pedicle (B). Note also that the function of clasping spines in A is clear whereas in B reminds unresolved.