In politics, “right versus left” is a common theme. Although it is less frequently that this motif is carried to sedimentologic matters, it was 50 years ago that Kornicker et al. explored the question: Why do right or left valves occur in excess abundance in recent and ancient sediment accumulations? Their study explored the distribution of clam valves on the recent beach of Mustang Island, Texas. The results indicated that a differentiation is statistically significant only in valves larger than 69.5 mm, interpreted to represent the influence of “high energy surf” in separating valves. Shell attributes such as weight, ornamentation, and projections did not impact the distribution of valves. And, like politics, neither right nor left own a monopoly on boring, and it is not a control on differentiation.
Factors Affecting the Distribution of Opposing Mollusk Values by Louis S. Kornicker, Charles D. Wise, Juanita M. Wise, Journal of Sedimentary Petrology, v. 33, p. 703-712.