Marjuman (Cambrian) agnostoid trilobites of the Cow Head Group, western Newfoundland
Shelf-derived limestone boulders in debris flows of the Cow Head Group, western Newfoundland, have yielded rich mid- to Upper Cambrian trilobite faunas. The agnostoid component of Marjuman boulders consists of 23 species assigned to 11 genera; Kormagnostus boltoni and Kormagnostus ? copelandi are ne...
| Published in: | Journal of Paleontology |
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| Main Authors: | , , |
| Format: | Article in Journal/Newspaper |
| Language: | English |
| Published: |
Cambridge University Press (CUP)
1996
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| Subjects: | |
| Online Access: | https://doi.org/10.1017/s0022336000023854 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022336000023854 |
| Summary: | Shelf-derived limestone boulders in debris flows of the Cow Head Group, western Newfoundland, have yielded rich mid- to Upper Cambrian trilobite faunas. The agnostoid component of Marjuman boulders consists of 23 species assigned to 11 genera; Kormagnostus boltoni and Kormagnostus ? copelandi are new. Cladistic parsimony analysis of the Ptychagnostidae Kobayashi reduces this family to 3 genera: Ptychagnostus Jaekel, Pseudophalacroma Pokrovskaya and Lejopyge Hawle and Corda; Ptychagnostus includes three non-obligate subgenera: P. (Ptychagnostus) (= Tomagnostus Howell); P. (Goniagnostus ) Howell and P. (Aotagnostus ) öpik (= Myrmecomimus öpik). Correlation with zonations established in northern Canada and Utah indicates that the Cow Head Group includes a nearly complete sequence of agnostoid faunas from the mid-Cambrian Ptychagnostus gibbus Zone to the Upper Marjuman Cedaria brevifrons Zone. |
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