There are only three known trilobite horizons in the rather extensive Cambrian exposures in NE Washington.
1. Lower Cambrian Nevadia addyensis horizon in the type section of the Addy Quartzite, near Addy, Washington.
Trilobites:
Nevadia addyensis Okulitch, 1951
Olenellus argentus Walcott, 1910 (may be more correctly known as Esmeraldina argenta because of a 1996 unpublished description by L. Bohach).
Reference: Okulitch, Vladimir J., 1951 "A Lower Cambrian fossil locality near Addy, Washington", Journal of Paleontology, v. 25, no. 3, pages 405-407.
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2. Middle Cambrian Metaline Limestone, Pend Oreille County, Washington
The trilobites were first described by Kenneth P. McLaughlin & Betty B. Enbysk, 1950, "Middle Cambrian Trilobites from Pend Oreille County, Washington", Journal of Paleontology, v. 24, no. 4, pages 466-471. This fauna is currently being studied by Stewart Hollingsworth. Many new spcies are among those below that were found by Dave Morgan.
Trilobites:
Bathyuriscus
sp. (Morgan, pers. comm.)
Chancia sp. (Morgan, pers comm.)
Elrathia
longiceps Resser, 1938
Elrathina cordillerae (Rominger, 1887) (= Ptychoparella
cordillerae)
Kootenia sp. (Morgan, pers. comm.)
Ogygopsis
elongata (McLaughlin and Enbysk,
1950)
Ogygopsis klotzi (Rominger, 1887)
Olenoides cf.
serratus
Olenoides maladensis Resser, 1939
Pagetia sp. (Morgan, pers. comm.)
Poliella
sp. (Morgan, pers. comm.)
Ptarmigania sp. (Morgan,
personal communication)
Ptarmiganoides sp.
(Morgan, personal communication)
Ptychoparella cordillerae
(Rominger, 1887)
Taxioura elongata McLaughlin and Enbysk, 1950 (= Ogygopsis
elongata)
Wenkchemnia sp.? (Morgan,
personal communication)
Yokoaspis sp. (Morgan,
personal communication)
Zacanthoides
n. sp. (Morgan, personal communication)
new unidentified kochaspid = Chancia
sp.
*Note: "Taxioura" = Ogygopsis; "Elrathina" = Ptychoparella
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3. Middle Cambrian Glossopleura Biozone fauna, Clear Lake, Spokane
County, Washington.
Trilobites:
Amecephalus sp.
Glossopleura sp.
Zacanthoides sp.
*Note: The site is on a military recreation base and access is highly restricted. The only publication on this site so far is an abstract (below), courtesy of Dr. Linda McCollum. Publication of the full article is in progress.
EARLY MIDDLE CAMBRIAN (GLOSSOPLEURA BIOZONE) TRILOBITES IN A STEPTOE
SURROUNDED BY COLUMBIA RIVER BASALT NEAR SPOKANE, WASHINGTON
HAMILTON, Michael M., WA Dept. of Natural Resources, Division of
Geology and Earth Resources, 904 W Riverside, Rm 215, Spokane, WA 99201-1011,
hamfam@ieway.com, DERKEY, Robert E., WA Dept. of Natural Resources,
Division of Geology and Earth Resources, 904 W Riverside, Rm 215, Spokane, WA
99201-1011, and MCCOLLUM, Linda B., Geology Department, Eastern
Washington Univ, 130 Science Building, Cheney, WA 99004
The basement under the Columbia River Basalt Group is exposed in a number of
steptoes in west-central Spokane County, Washington. The rocks within these
steptoes consist mostly of sedimentary strata, which have been locally
metamorphosed to calc silicates by late Mesozoic granites. The affinity of these
rocks in the various steptoes is still largely unknown, although they had
previously been assigned to the Ravalli Group or the Wallace Formation of the
Proterozoic Belt Supergroup, as these formational groups occurred to the east in
Idaho and to the north in northeastern Washington. Alternatively, the quartzites
and calc silicates may be part of the Proterozoic Deer Trail Group, which crops
out 50 km northwest of Spokane.
One small steptoe on the east side of Clear Lake, which is 10 km west-northwest
of the city of Cheney, Washington and 25 km southwest of Spokane, is an exposure
of relatively unmetamorphosed rock, beginning with a calcareous quartz arenite
(quartzite), overlain by shale containing minor limestones beds and then a
reddish mudrock facies. From the reddish mudrock, which had been exposed during
construction activity completed several years ago, we discovered an early Middle
Cambrian trilobite fauna consisting of inarticulate brachiopods, hyolithids, and
trilobite genera including Amecephalus, Glossopleura, and Zacanthoides.
This is the first reported occurrence of a Glossopleura Biozone fauna in
Washington and the only report of fossiliferous strata of Paleozoic age within
this region of the Columbia plateau. The nearest known occurrence of this age
fauna is from the upper Rennie Shale and basal Lakeview Limestone, located some
100 km to the northeast on the southern flank of Packsaddle Mountain, near
Lakeview, Idaho. The rocks and fauna of this small steptoe have a closer
affinity to this Idaho location than to the more extensive upper Proterozoic and
Cambrian facies exposed in northeastern Washington.
Geological Society of America Abstracts with Programs, Vol. 35, No. 6,
September 2003, p. 159.
REFERENCES:
HAMILTON, Michael M., DERKEY, and MCCOLLUM, Linda B. (2003) EARLY MIDDLE CAMBRIAN (GLOSSOPLEURA BIOZONE) TRILOBITES IN A STEPTOE SURROUNDED BY COLUMBIA RIVER BASALT NEAR SPOKANE, WASHINGTON. Geological Society of America Abstracts with Programs, Vol. 35, No. 6, September 2003, p. 159.
McLaughlin, K. P. & Enbysk, B. B., 1950, "Middle Cambrian Trilobites from Pend Oreille County, Washington", Journal of Paleontology, v. 24, no. 4, pages 466-471.
Okulitch, Vladimir J., 1951 "A Lower Cambrian fossil locality near Addy, Washington", Journal of Paleontology, v. 25, no. 3, pages 405-407.
Comments:
This page and the faunal lists were compiled by Linda B. McCollum, Geology Department, Eastern Washington University, from both published and unpublished sources. If you know of any other species from Washington State, or have additional specimens or information, please contact Dr. Linda McCollum at: Eastern Washington University 130 Science Building Cheney, WA99004-2439USA, lmccollum@mail.ewu.edu
Many thanks to David Morgan for most of the specimens on this page! The new kochaspid, found by his son Sterling, may constrain the age of the Metaline Formation to being slightly older than first thought. Sterling is also responsible for many of the other rare finds in the Metaline.
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