Publication Date:
1995-07-01
Description:
Walcott described the If fauna from Silver Peak Range, Nevada in 1910 as consisting of Nevadia weeksi n. sp. and gen. and Holmia rowei n. sp. (herein recognized as Esmeraldina rowei). Being the oldest trilobite fauna known at the time, it played an important roll in Walcott's locating the base of his Lower Cambrian Waucoban Series. The original If collection is reviewed, as is more material collected near the type locality, “Nevadella” Zone, Montenegro Member of the Campeto Formation. Additional trilobite taxa herein recognized in the If collection are Esmeraldina? cometes n. sp., Esmeraldina lidensis n. sp., Palmettaspis consorta n. gen. and sp., and Palmettaspis parallela n. sp. A close similarity between E. rowei and the type species for Holmia in Baltica led Walcott to a controversial Laurentia–Baltica correlation. His incorporation of three trilobite taxa among his syntypes for Holmia rowei also posed a problem. Overriding these faults was Walcott's foresight in using the 1f fauna in his Waucoban concept. Even today, after the 1992 international agreement to lower the base of the Cambrian to a pre-trilobite horizon, the Waucoban is being applied in Canada to upper Lower Cambrian strata.
Print ISSN:
0022-3360
Electronic ISSN:
1937-2337
Topics:
Geosciences
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