caa a22 4500 388016876 CHVBK 20180307124913.0 cr unu---uuuuu 161130e199807 xx s 000 0 eng 10.1017/S0022336000040373 doi S0022336000040373 pii (NATIONALLICENCE)cambridge-10.1017/S0022336000040373 Palmer A. R. Institute for Cambrian Studies, 445 N. Cedarbrook Rd., Boulder, Colorado 80304-0417, <palmera@spot.colorado.edu> Terminal Early Cambrian extinction of the Olenellina: Documentation from the Pioche Formation, Nevada [Elektronische Daten] [A. R. Palmer] The extinction of the Olenellina on Laurentia can be located within centimeters in the C-shale or uppermost Combined Metals Limestone members of the Pioche Formation in eastern Nevada. Olenellid species diversity beneath the extinction boundary is not diminished. One of the richest Laurentian intervals for articulated olenellids is in the 50 centimeters of shale immediately below the extinction boundary at Ruin Wash. Additional morphological information about some of the species comes from a silicified fauna 1.8 m below the extinction boundary at Hidden Valley. The olenellid fauna from the 2-meter interval below the extinction boundary is described. Questions about current generic and subgeneric relationships are discussed. Among general observations, intraspecific variability unrelated to size or taphonomic effects is minimal for most species; at least two species may have been capable of enrollment; and visual surfaces of one species show no evidence of facets. New species include: Olenellus (Olenellus?) fowleri, Olenellus (Paedeumias) chiefensis, Olenellus (Paedeumias) terminatus, Bolbolenellus brevispinus, and Nephrolenellus geniculatus. Olenellus (Olenellus) gilberti Meek and Olenellus (Olenellus) howelli Meek are revised. Copyright © The Paleontological Society Journal of Paleontology Cambridge University Press 72/4(1998-07), 650-672 0022-3360 72:4<650 1998 72 JPA https://doi.org/10.1017/S0022336000040373 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1017/S0022336000040373 text/html Onlinezugriff via DOI NATIONALLICENCE 100 1- Palmer A. R. Institute for Cambrian Studies, 445 N. Cedarbrook Rd., Boulder, Colorado 80304-0417, <palmera@spot.colorado.edu> NATIONALLICENCE 773 0- Journal of Paleontology Cambridge University Press 72/4(1998-07), 650-672 0022-3360 72:4<650 1998 72 JPA CC0 http://creativecommons.org/publicdomain/zero/1.0 nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-cambridge