Reno Mbr, Franconia Fm - Bed 2, Rileys Coulee section (Cambrian of the United States)

Where: Wabasha County, Minnesota (44.4° N, 91.2° W: paleocoordinates 20.4° S, 79.8° W)

• coordinate based on nearby landmark

• outcrop-level geographic resolution

When: Reno Member (Franconia Formation), Franconian (497.0 - 485.4 Ma)

• LITHOSTRATIGRAPHY: Reno Mbr of the Franconia Fm (following Berg 1953, 1954). STRATIGRAPHIC RELATIONS: From the Reno Mbr, the upper member of the Franconia Fm, which is underlain by the Tomah Mbr. The Franconia Fm is overlain by the Black Earth Mbr of the St Lawrence Fm. AGE: From the middle of the Ptychaspis striata zonule, Ptychaspis-Prosaukia Zone (Howell et al. 1944) of the Middle Croixan. STRATIGRAPHIC POSITION: Unit 2, 0.5 ft thick, at the base of a 40+ ft thick section.

• bed-level stratigraphic resolution

Environment/lithology: offshore; lithified, bioturbated, fine-grained, glauconitic sandstone

• ENVIRONMENT: From text: "...shallow marine water on a slightly irregular shelf...deposition in quiet water, protected from more aggitated environments", assigned to a siliciclastic - offshore environment. TECTONIC SETTING: Tectonic data not reported in text. SEQUENCE STRATIGRAPHY: Sequence stratigraphic data not reported.
• GENERAL LITHOLOGY: Fine-grained, cross-laminated, highly glauconitic sandstone alternating with massive, mottled beds of glacuonitic wormstone. LITHIFICATION: Assumed to be lithified, based on age and observation of figured specimens.

Size class: macrofossils

Preservation: cast, mold/impression

Reposited in the USNM

Collection methods: bulk, quarrying,

• COLLECTOR: R.E Grant. REPOSITORY: USNM

Primary reference: R. E. Grant. 1962. Trilobite distribution, upper Franconia Formation (Upper Cambrian), southeastern Minnestoa. Journal of Paleontology 36(5):965-998 [A. Miller/A. Hendy]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 62118: authorized by Austin Hendy, entered by Austin Hendy on 12.07.2006

Creative Commons license: CC BY (attribution)

Taxonomic list

• COMPLETENESS: Limited to trilobita, exhaustive for trilobites, however. NOMENCLATURE: Authoritative publication, but somewhat historic nomenclature.
Show authors, comments, and common names
Trilobita
 Olenida - Idahoiidae
Wilbernia pero, "Idahoia serapia" = Saratogia
Wilbernia pero Walcott 1890 trilobite
"Idahoia serapia" = Saratogia trilobite
 Ptychopariida - Elviniidae
Drumaspis tanycodia
Drumaspis tanycodia Grant 1962 trilobite
 Asaphida - Dikelocephalidae
Monocheilus anatinum, Prosaukia ambigua, Prosaukia misa
Monocheilus anatinum Hall 1863 trilobite
Prosaukia ambigua Ulrich and Resser 1933 trilobite
Prosaukia misa Owen 1852 trilobite
 Asaphida - Ptychaspididae
Ptychaspis striata, Ptychaspis miniscaensis
Ptychaspis miniscaensis Owen 1852 trilobite
  - Ellipsocephaloididae
Ellipsocephaloides gracilis