The first Paleozoic stenopodidean from the Huntley Mountain Formation (Devonian–Carboniferous), north-central Pennsylvania

Abstract

A single specimen of a shrimp-like crustacean, Devonostenopus pennsylvaniensis, new genus and species is described from the Huntley Mountain Formation, which is Devonian–Carboniferous (Mississippian) in age. The specimen was collected in north-central Pennsylvania. Devonostenopus pennsylvaniensis is attributed to Stenopodidae. Co-occurrence of the specimen with pinnules of Archaeopteris halliana Goeppert, 1852, suggests that it is Devonian in age. Occurrence of a stenopodidean in the Devonian of North America is significant, as only three definitive decapods have been previously described from the Paleozoic and only two have been described from the Devonian. The earliest stenopodideans described to date are Cretaceous (Cenomanian and Santonian) in age. As such, Devonostenopus pennsylvaniensis extends the geologic range of Stenopodidea from Cretaceous to Late Devonian. Occurrence of a stenopodidean in the Devonian of North America, as well as the occurrence of the only two other known Devonian decapods in North America, suggests that Laurentia might have been a major area of endemism for Devonian decapods.

A phylogenomic framework, evolutionary timeline and genomic resources for comparative studies of decapod crustaceans

“…Overall, our divergence time estimates imply a significant cryptic history for decapods ( figure 3), which may motivate revision of Palaeozoic fossils that have been suggested as decapods [63,[70][71][72], in a more explicit phylogenetic framework. We infer a lack of cladogenesis among the deep lineages during the Permian, followed by diversification in most crown groups in the Triassic.…”

A Phylogenomic Framework, Evolutionary Timeline, and Genomic Resources for Comparative Studies of Decapod Crustaceans

“…Based on monophyletic Palinuridae (Figure 3), their crown divergence occurred in the Late Triassic (similar to previous estimates; [15]), and crown Scyllaridae in the Early Cretaceous (about 87 Myr younger than Bracken-Grissom et al [15]). These age estimates predate the wealth of Jurassic and Cretaceous fossil achelatan larvae [60,61], implying bizarre stem-groups may have persisted throughout the Mesozoic alongside the crown. Our phylogenetic results also support the division of Palinuridae into distinct clades of Silentes and Stridentes, the latter bearing an enlarged antennular plate used in sound production in adults [15,62,63].…”

“…Only three fossil species have been described, and none have yet been evaluated using phylogenetics. Of these, two, Devonostenopus pennsylvaniensis Jones et al 2014 [61] and Jilinocaris chinensis Schram et al 2000 [62], were placed within Stenopodidea on characters that were admittedly poorly preserved and not conclusive. In contrast, P. pasinii is better preserved, and has a number of diagnostic characters confirming its stenopodidean affinity [59].…”

Fossil Crustaceans as Parasites and Hosts

“…Given the estimated occurrence of calanoid copepods as far back as the Silurian, based on a phylogeny using morphological and molecular evidence (Selden et al, 2010), and the presence of decapods since the Devonian (e.g. Feldmann and Schweitzer, 2010;Gueriau et al, 2014;Jones et al, 2014), Early Jurassic and older occurrences are theoretically possible as the two host groups would have been available. Unfortunately, no rigorous phylogenetic analyses of epicarideans including estimated divergence times are known to us.…”