The Proof is in the Pouch: Tealliocaris is a Peracarid

Abstract

Tealliocarid eumalacostracans, known from Late Devonian–Carboniferous marine, non-marine, and estuarine strata of North America, continental Europe, and the United Kingdom, are here transferred from Eucarida: Decapoda back to Peracarida: Pygocephalomorpha. Species included in Tealliocaris exhibit a suite of peracaridan and pygocephalomorphan synapomorphies, including the presence of an oostegite marsupium in females, a distinct terminal telson lobe, and a pair of lateral telson lobes. Purported decapodan characters, e.g. complete fusion of the car- apace and thoracic tergites, and the presence of only five pereiopods, in Tealliocaris seem to be poorly supported. A phylogenetic analysis included herein fully supports inclusion of Tealliocaris in Peracarida and in Pygocephalomorpha.