FOSSIL OYSTERS RADIATE COLOR PATTERNS

Color and color patterns are rarely preserved in the fossil record. Original coloration naturally degrades over time. Despite this, occasional color and/or color patterns remain present. Radial banding in fossil oysters has been reported sporadically from the Gryphaeidae family in the literature, including 1 species each from the late Cretaceous of Utah, New Jersey and Texas (W. L. Stokes et.al., 1964) and one from the Paleocene of Alabama (C. Swann – 1986).

In 2015, a beach sand replenishment project on North Topsail Beach provided hundreds of spectacularly banded, Oligocene age, River Bend Formation, Pycnodonte paroxis specimens. Though diagenetically altered, the bands on these specimens clearly reflect the original color patterns, with visible tan lines of varying widths and frequency on each specimen that converge at the beak. These lines are often offset on the shell at points of injury. Even when the lines are no longer visible in natural light, they will fluoresce in UV.

Since 2015, the author has specifically looked for oysters with color patterning, and to date has collected 15 different species from the order Ostreida (from 10 different genus and 2 families), ranging in age from the Cretaceous to the Pleistocene. All but one have multiple specimen examples, and many have specimens of both young and mature individuals. All have radial banding and all 15 species are banded exclusively on the left valve. To our knowledge, this represents the largest and most diverse collection of oysters with coloration in existence.