Planetary rotation and invertebrate skeletal patterns: Prospects for extant taxa

It has been two decades since Wells proposed that the duration of absolute geologic time could be estimated using growth patterns found in fossil corals. Since then, the temporal and environmental records encoded in the accretionary skeletons of other invertebrates also have been studied. Although extensive research on the significance of skeletal patterns has been done on bivalved molluscs, other taxa such as the brachiopods, bryozoans, cephalopods and echinoderms are in need of further study. For two taxa, the nautiloids and brachiopods, additional growth pattern data are presented here. These data indicate that erroneous geophysical conclusions about the length of the synodic lunar month were previously reached using what now appear to be unfounded assumptions about the temporal significance of their growth patterns. Assumptions regarding the temporal and environmental information contained in the skeletons of these poorly studied taxa need to be replaced by more extensive analyses using standardized techniques. Only then will we arrive at correct conclusions about the dynamical history of the Earth-Moon system.