FB Sinkhole (Ordovician of the United States)

Where: Idaho (42.1° N, 111.7° W: paleocoordinates 7.3° S, 81.8° W)

• coordinate estimated from map

• outcrop-level geographic resolution

When: Bellefontia - Xenostegium trilobite zone, Garden City Formation, Gasconadian (485.4 - 477.7 Ma)

• "A sample from this horizon yielded 25 conodont elements, suggesting a stratigraphie age equivalent to trilobite zones A or of the lower Ibexian (lower Tremdocian) (Ray Ethington, University of Missouri, personal communication, 1999; Ross, 1949; Hintze,

•1973; Landing, 1981), although clearly diagnostic taxa (e.g., Cordylodus Pander, 1856, among others) were lacking. Later work indicates this stratigraphie interval correlates regionally with the upper Skullrockian Stage or upper part of trilobite zone in the House Formation at the Ibexian Series type section for the Early Ordovician, western Utah (Ross et al., 1997). This age correlates with the earliest Ordovician, time slice 1a, of the global biozo- nation (Webby et al., 2004)." PJW: authors note that the Garden City goes up to at least Zone E, but that's the upper part of the formation & this is the lower part.

• formation-level stratigraphic resolution

Environment/lithology: shallow subtidal; lithified limestone

Size class: macrofossils

Primary reference: T. E. Guensburg and J. Sprinkle. 2009. Solving the mystery of crinoid ancestry: new fossil evidence of arm origin and development. Journal of Paleontology 83(3):350-364 [D. Wright/D. Wright]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 191404: authorized by David Wright, entered by David Wright on 26.01.2018

Creative Commons license: CC BY (attribution)

Taxonomic list

Crinoidea
 Pentacrinoidea -
Apektocrinus ubaghsi n. sp. Guensburg and Sprinkle 2009 Sea lily