Journal article
Classification of the Late Cambrian (Steptoean) trilobite genera Cheilocephalus Berkey, 1898 and Oligometopus Resser, 1936 from Laurentia
Canadian Journal of Earth Sciences, Vol.45(6), pp.725-744
2008
DOI: 10.1139/E08-026
Abstract
All recent work has assigned the genera Cheilocephalus Berkey, 1898 and Oligometopus Resser, 1936 to the family Cheilocephalidae Shaw, 1956, a small group of largely Laurentian trilobites from the Late Cambrian Steptoean Stage. New data from Nevada and Newfoundland indicate that the Cheilocephalidae is polyphyletic and that Cheilocephalus and Oligometopus are allied with different superfamilies. The Cheilocephalidae, which includes Cheilocephalus and Pseudokingstonia Palmer, 1965, is assigned to the Dameselloidea Kobayashi, 1935, and a pygidium from the Cow Head Group of Newfoundland indicates that Cheilocephalus first appears in the late Marjuman. The Dameselloidea disappeared on other continents at an extinction interval at the end of the Marjuman, but Cheilocephalus survived and underwent modest diversification in Laurentia in the succeeding Steptoean Stage. Oligometopus is transferred to the leiostegioidean family Leiostegiidae Bradley, 1925. The genus shows closest affinities with such Gondwanan genera as Idamea Whitehouse, 1939, and its appearance in mid-Steptoean strata records immigration of the Leiostegoidea into shelf-margin environments of Laurentia.
Details
- Title: Subtitle
- Classification of the Late Cambrian (Steptoean) trilobite genera Cheilocephalus Berkey, 1898 and Oligometopus Resser, 1936 from Laurentia
- Creators
- Stephen R. Westrop - University of OklahomaJennifer D. Eoff - University of OklahomaTin-Wai Ng - University of IowaAlyce A. Dengler - University of OklahomaJonathan M. Adrain - University of Iowa
- Contributors
- Jisuo Jin
- Resource Type
- Journal article
- Publication Details
- Canadian Journal of Earth Sciences, Vol.45(6), pp.725-744
- DOI
- 10.1139/E08-026
- ISSN
- 0008-4077
- eISSN
- 1480-3313
- Language
- English
- Date published
- 2008
- Academic Unit
- Earth and Environmental Sciences
- Record Identifier
- 9984230126002771
Metrics
7 Record Views