USGS 6134-CO. Dix River Crossing of Route 52 (Ordovician of the United States)

Where: Boyle County, Kentucky (37.6° N, 84.7° W: paleocoordinates 27.6° S, 63.5° W)

• coordinate based on nearby landmark

• small collection-level geographic resolution

When: Curdsville Limestone Member (Lexington Limestone Formation), Turinian (460.9 - 449.5 Ma)

• "Lower 3 ft of Curdsville Limestone Member"

• bed-level stratigraphic resolution

Environment/lithology: shallow subtidal; lithified, shelly/skeletal limestone

• "marine transgression, with higher energy, shallow-water deposits grading upward into lower energy deposits."
• "The lower 10-ft-thick unit is light-colored bioclastic limestone that consists of calcirudites, and crossbedded and ripple-marked calcarenites. The lower unit is composed of well-sorted, abraded skeletal debris having about 5 to 10 percent quartz sand."

Size class: macrofossils

Preservation: replaced with silica

Reposited in the UNSM

Primary reference: G.P. Wahlman. 1992. Middle and Upper Ordovician symmetrical univalved mollusks (Monoplacophora and Bellerophontina) of the Cincinnati Arch region. United States Geological Survey Professional Paper 1066(O):1-123 [P. Wagner/P. Wagner/E. Ito]more details

Purpose of describing collection: general faunal/floral analysis

PaleoDB collection 100231: authorized by Pete Wagner, entered by Hallie Street on 02.12.2010, edited by Pete Wagner

Creative Commons license: CC BY (attribution)

Taxonomic list

 Cyrtodontida - Cyrtodontidae
Vanuxemia gibbosa2 clam
415 valves
Cyrtodonta subovata2 clam
59 valves
 Protobranchia - Ctenodontidae
Ctenodonta aff. nasuta2 Hall 1847 clam
four valves
Ctenodonta aff. longa2 Ulrich 1894 clam
one valve
Tancrediopsis sp.2 Beushausen 1895 clam
34 valves
 Bellerophontida - Pterothecidae
"Carinaropsis acuta" = Carinaropsis minima, Pterotheca expansa
"Carinaropsis acuta" = Carinaropsis minima Ulrich and Scofield 1897 snail
Pterotheca expansa Emmons 1842 snail
 Bellerophontida - Tropidodiscidae
"Tropidodiscus subacutus" = Alaskadiscus subacutus
"Tropidodiscus subacutus" = Alaskadiscus subacutus Ulrich and Scofield 1897 snail
 Neoloricata - Lepidopleuridae
Helminthochiton blacki2 chiton
15 intermediate plates, one tail plate.
  - Hudsonasteridae
"Promopalaeaster finei" = Mesopalaeaster finei1
"Promopalaeaster finei" = Mesopalaeaster finei1 Ulrich 1879 sea star
 Comarocystitida - Amygdalocystitidae
 Mitrata - Anomalocystitidae
Enoploura cf. punctata3 Bassler 1932
 Strophomenida - Rafinesquinidae
Rafinesquina sp.2 Hall and Clarke 1892
 Pentamerida - Camerellidae
? Camerella sp.2 Billings 1859
 Atrypida - Anazygidae
Zygospira sp.2 Hall 1862
 Rhynchonellida - Rhynchotrematidae
 Orthida - Draboviidae
? Pionodema sp.2 Foerste 1912
 Orthida - Dalmanellidae
Dalmanella sp.2 Hall and Clarke 1892
 Orthida - Platystrophiidae
Platystrophia amoena2 McEwan 1919
Platystrophia amoena longicardinalis