ammonites
Midco Locality 15 (Permian of the United States)

Where: Oklahoma (36.3° N, 97.3° W: paleocoordinates 2.7° N, 26.5° W)

• coordinate stated in text

• small collection-level geographic resolution

When: Midco Member (Wellington Formation), Artinskian (290.1 - 279.5 Ma)

• group of beds-level stratigraphic resolution

Environment/lithology: lacustrine; lithified, dolomitic, argillaceous lime mudstone

• Salty playa lake. The lower layer shows sedimentational and organic features which suggest that it was laid down close to the shore and that most of its biota was washed into the lake. The matrix and biota of the middle layer, which is highly irregular and characterized by pink partings, were probably transported to the water by violent dust storms. The upper layer is highly argillaceous, and was deposited under strongly saline conditions; insects are rare but they are very well preserved.
• Several layers of fine-grained, compact, argillaceous dolomitic lime stone, separated by fissile shale. Three of the limestone layers contain insects, and for convenience of reference they have been designated the lower, middle and upper insect layers.

Size classes: macrofossils, mesofossils

Preservation: mold/impression

Primary reference: F. M. Carpenter. 1947. Lower Permian Insects from Oklahoma. Part 1. Introduction and the Orders Megasecoptera, Protodonata, and Odonata. Proceedings of the American Academy of Arts and Sciences 76:25-54 [M. Clapham/M. Clapham] more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 104824: authorized by Matthew Clapham, entered by Matthew Clapham on 10.02.2011, edited by Jered Karr

Creative Commons license: CC BY-NC-ND (attribution-noncommercial-no derivatives)