Skip to content Skip to navigation

Article: Evolutionary morphology of oblique ribs of bivalves

Publication: Palaeontology
Volume: 46
Part: 4
Publication Date: July 2003
Page(s): 709 724
Author(s): Antonio G. Checa and Antonio P. Jiménez-Jiménez
Addition Information

How to Cite

CHECA, A. G., JIMÉNEZ-JIMÉNEZ, A. P. 2003. Evolutionary morphology of oblique ribs of bivalves. Palaeontology46, 4, 709–724.

Online Version Hosted By

Wiley Online Library
Get Article: Wiley Online Library [Pay-to-View Access] |


Fossil bivalves bearing oblique ribs first appeared in the Mid Ordovician but their diversity remained low during the Palaeozoic. The diversity soon increased after the Early Triassic, peaking in the Early Cretaceous. The Palaeozoic-Mesozoic record is dominated by burrowing bivalves (mainly pholadomyoids and trigonioids), which developed oblique ribs with symmetric profiles, probably adapted for shell reinforcement, although there are indications that the ribs of trigonioids also enhanced burrowing efficiency. After the Paleocene, the main groups of burrowing bivalves were veneroids (primarily tellinoideans and lucinoideans) and nuculoids, which generated oblique ribs of the shingled type, adapted to increase burrowing efficiency. The inferred change in function at the Mesozoic/Cenozoic boundary can be correlated with an increase in mean mobility of the bivalve faunas bearing oblique ribs through time. This implies a major ecological cause for the observed temporal patterns, which forced bivalve faunas to burrow more rapidly and efficiently. In particular, either the Phanerozoic increase in the diversity of durophagous predators or the accelerating rate of sediment reworking (both being a consequence of the Mesozoic Marine Revolution), or both, could have provided the necessary evolutionary force.
PalAss Go! URL: | Twitter: Share on Twitter | Facebook: Share on Facebook | Google+: Share on Google+