Where: Alexander County, Illinois (37.2° N, 89.5° W: paleocoordinates 24.7° S, 62.9° W)

• coordinate estimated from map

• local area-level geographic resolution

When: Normalograptus extraordinarius graptolite zone, Leemon Formation, Gamachian (449.5 - 443.7 Ma)

• Amorphognathus ordovicicus conodont zone

•Conochitina scabra chitinozoan zone

•Top of Normalograptus extraordinarius and Amorphognathus ordovicicus zones.

•Marks end of HICE

• group of beds-level stratigraphic resolution

Environment/lithology: ooidal, gray, argillaceous limestone

Size class: macrofossils

Primary reference: T. E. Savage. 1913. Stratigraphy and paleontology of the Alexandrian Series in Illinois and Missouri. Part I. Illinois Geological Survey, Bulletin 23:1-124 [G. Webster/G. Webster]more details

Purpose of describing collection: biostratigraphic analysis

PaleoDB collection 173289: authorized by Pete Wagner, entered by Pete Wagner on 15.09.2015

Creative Commons license: CC BY (attribution)