Isolated mantis shrimp dactyli from the Pliocene of North Carolina and their bearing on the history of Stomatopoda

Resumen

We describe 54
fragmentary specimens from the Pliocene of North Carolina that
represent isolated dactyli of mantis shrimps. These specimens are
preserved uncompressed within three dimensions in calcium phosphate.
The dactyli have an estimated maximum length of 15 millimeters and
bear six spines. The specimens appear to be hollow and preserve fine
details, especially a narrow crest on the dorsal side of the spines,
a functional blade edge that has not been previously found on any
fossil stomatopod. The specimens are provisionally attributed to the
species Squilla empusa, found nowadays along the entire East coast
of the United States of America. Fossil occurrences are known from
the Pleistocene of Maryland and from the late Pleistocene or early
Holocene of Connecticut. Though isolated dactyli are less
informative on the taxonomic level, they can be important on the
paleo-ecological level, positively demonstrating the presence of
ambush predators in an investigated paleo-community. Given the
scarce stomatopod fossil record and the exceptional
three-dimensional preservation, the finding of these specimens,
despite their fragmentary nature, is regarded as
significant.