0000000000427199
AUTHOR
Antonio P. Jiménez‐jiménez
Further comments on the origin of oysters
In his comment to our recent paper (Marquez-Aliaga et al. 2005), Hautmann (2006) raises two interesting questions: (a) the ambivalent attachment to the substrate recognized in the species cristadifformis Schlotheim, 1820 and spondyloides Schlotheim, 1820, which we include into the Ostreoidae genus Umbrostrea, is in conflict with the sinistral attachment usually recognized as an autapomorphy of the group and (b) antimarginal ribs are not valid as a character linking Prospondylus acinetus Newell and Boyd, 1970 and early oysters (our proposal of derivation), because they appear in several unrelated families of bivalves. Moreover, Hautmann (2005), finds additional difficulties in accepting our …
Early oysters and their supposed Permian ancestors
The origin of oysters is a much debated palaeontological issue. Recent morphological studies indicate that oysters are characterized by a particular ribbing pattern, the so-called antimarginal ribs which are characterized by a proper morphogenetic pattern. Therefore antimarginal ribs can be used as a diagnostic character in phylogeny. The earliest recognized bivalve displaying diagnostic features of oysters (sinistral attachment to the substrate, typical hinge and ligament structure, and antimarginal ribs) is Ostracites cristadifformis Schlotheim, 1820 first appearing in the Anisian of Europe. This common species was later attributed to Enantiostreon and is here transferred to Umbrostrea. S…