Pushing the limits to the north – a fossil mantis shrimp from Oregon, USA

We describe a new mantis shrimp, Squilla erini sp. nov., from the late Oligocene to early Miocene Nye Mudstone of Oregon, USA. The new species is placed within the genus Squilla based on the presence of carinae on the tergites, denticles between the submedian spines of the telson, and absence of movable apices on the telson spines. Squilla erini sp. nov. differs in telson morphology from all 27 modern species of mantis shrimps occurring on the West coast of North America (down to the Gulf of Mexico). It appears also to differ from the six known species of fossil mantis shrimps from the US West Coast. The species is unique in possessing only a single pair of denticles between the submedian spines of the telson. Squilla erini sp. nov. extends the distribution of stomatopods along the West Coast further north; until now mantis shrimps had been only reported from California. Oligocene and Miocene climate was warmer than today, therefore a further northern distribution of mantis shrimps is in concordance with palaeoclimatic reconstructions.