Ceratiocarisfrom the Silurian Waukesha Biota, Wisconsin

Abstract

Phyllocarids of the Waukesha Biota were systematically and taphonomically evaluated. Three Ceratiocaris species are present in the biota: C. macroura Collette and Rudkin, 2010; C. papilio Salter in Murchison, 1859; and C. pusilla Matthew, 1889. Specimens range in completeness from nearly complete, including the cephalic to caudal regions, to isolated telsons and furcae. Evidence of Salter's position is present in only three specimens. Relatively complete specimens are interpreted to represent corpses, rather than molts; whereas specimens including only the pleon and caudal region, or caudal region, and specimens with evidence of Salter's position likely represent exuviae. Specimens are preserved essentially as compression fossils exhibiting two types of preserved cuticle: brown inner cuticle, which tends to be impressed over the topography of bedding planes on which specimens are preserved, and blue-gray phosphatized cuticle exhibiting sub-millimeter scale relief. Cuticle phosphatization likely occurred during early diagenesis. The presence of characteristic near-shore species and C. pusilla, only known from turbidite facies, interpreted to possibly represent a marine trough, suggests that the Waukesha phyllocarid assemblage might represent a transported assemblage, rather than a biota, or that C. pusilla from the Jones Creek Formation was transported basinward in sediment gravity flows.

Appendages, functional morphology and possible sexual dimorphism in a new ceratiocaridid (Malacostraca, Phyllocarida) from the Early Devonian Hunsrück Slate (south‐western Germany)

“…Although it is known that different species of Ceratiocaris may co‐occur at a given locality (Jones et al . ), we consider that the specimen PWL 2016/18‐LS is probably conspecific with the undetermined ceratiocarine archaeostracan figured by Bergström et al . (, fig.…”

“…The Silurian C. macroura Collette & Rudkin, has an exceptionally long telson spine with a telson spine to furca length ratio of about 4.0 (Collette & Rudkin ; Jones et al . ). The Ordovician species C. silicula (Bassler, ) is again much smaller and has a distinctly elongate carapace rendering a closer relationship to the Hunsrück Slate specimen unlikely.…”

“…; Jones et al . ) and Herefordshire biotas ( Cinerocaris magnifica ; Briggs et al . ), as well as from Burnham, Illinois ( Ceratiocaris macroura ; Jones et al .…”

“…5.3; Jones et al . , b), and the Early Devonian Hunsrück Slate ( Nahecaris stuertzi ; Bergström et al . ; Oryctocaris balssi ; Bergmann & Rust ; Heroldina rhenana (Broili, ); unpub.…”

Stranger than a scorpion: a reassessment of Parioscorpio venator, a problematic arthropod from the Llandoverian Waukesha Lagerstätte

“…In addition to Parioscorpio venator , other fossils that have been formally described include: a synziphosuran chelicerate, Venustulus waukeshaensis Moore et al ., 2005; a thylacocephalan arthropod, Thylacares brandonensis Haug et al ., 2014; a dasycladalean alga, Heterocladus waukeshaensis LoDuca et al ., 2003; and three species of phyllocarid crustacean within the genus Ceratiocaris (Jones et al . 2015).…”