KY Route 34 Roadcut (Ordovician to of the United States)

Where: Garrard County, Kentucky (37.7° N, 84.7° W: paleocoordinates 27.5° S, 63.5° W)

When: Curdsville Member (Lexington Limestone Formation), Soudleyan to Soudleyan (457.5 - 452.0 Ma)

• group of beds-level stratigraphic resolution

Environment/lithology: marine; lithified, massive, burrowed, calcareous packstone and lithified shale

• The Curdsville Member is poorly exposed at a limited number of outcrops and the nature of the exposure prevents the recovery of large numbers of specimens, limiting the study of this important fauna. The Curdsville Member is composed of horizontally bedded, massive, and highly fossiliferous packstones with a diverse assemblage of sponges, brachiopods, bryozoans, trilobites. In addition, there is a rich echinoderm assemblage including crinoids (Springer 1911; Parsley 1981), edrioasteroids (Bell 1979; Sumrall and Deline 2009), paracrinoids (Parsley 1981; Sumrall and Deline 2009), stylophorans (Parsley 1981), and cyclocystoids (Parsley 1981).

•The limestone bedding surface is uneven and extensively burrowed. The presence of direct attachment to the substrate by edrioasteroids and crinoids holdfasts indicates the development of firm- to hardgrounds. Large ripples are present on the bedding plane, which indicates high-energy deposition. In between the largescale ripples are muddy shale lenses that were deposited in the topographic lows that commonly preserved intact echinoderm remains (Cressman 1973). This pattern of thin shale layers preserving intact echinoderms is repeated throughout the section with the bulk of the unit composed of massive limestones that contain taxonomically uninformative disarticulated and highly abraded fossil hash (Fig. 2).

Size class: macrofossils

Preservation: original calcite, replaced with calcite

Primary reference: P. W. Hearn and B. Deline. 2012. A new species of Paradiabolocrinus from the Upper Ordovician of central Kentucky, USA. Southeastern Geology 49(1):25-30 [S. Cole/S. Cole]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 190385: authorized by Selina Cole, entered by Selina Cole on 06.12.2017

Creative Commons license: CC BY (attribution)

Taxonomic list

Crinoidea
 Diplobathrida - Rhodocrinitidae
Paradiabolocrinus teres n. sp. Hearn and Deline 2012 Sea lily
Archaeocrinus sundayae Cole et al. 2018 Sea lily