Phylogenetic analysis of the Olenellina Walcott, 1890 (Trilobita, Cambrian)

Phylogenetic analysis was used to evaluate evolutionary relationships withi n the Cambrian suborder Olenellina Walcott, 1890: special emphasis was plac ed on those laxa outside of the Olenelloidea. Fifty-seven exoskeletal chara cters were coded for 24 taxa within the Olenellina and two outgroups refera ble to the "fallotaspidoid' grade. The Olmelloidea, along with the genus Ga briellus Fritz, 1992. are the sister group of the Judomioidea Repina. 1979. The "Nevadioidea" Hupe, 1953 are a paraphyletic grade group. Four new gene ra are recognized, Plesionevadia, Cambroinyoella, Callavalonia, and Sdzuvom ia, and three new species are described, Nevadia fritzi. Cirquella nelsoni, and Cambroinyoella wallacei. Phylogenetic parsimony analysis is also used to make predictions about the ancestral morphology of the Olenellina. Tl;is morphology most resembles the morphology found in Plesionevadia and Pseudo judomia Egorova in Goryanskii and Egorova, 1964.