ABSTRACT: Middle Devonian chitinozoans from the Muscatatuck Group of Indiana belong to eight species of the genera Alpenachitina, Ancryochitina, Angochitina, Eisenackitina, and Hoegisphaera. The Chitinozoa are most abundant in the carbonate rocks that represent well-circulated open-water conditions and are low in diversity or are absent from lithographic and laminated dolomite representing the shallower, more restricted environments. The local range zones of the chitinozoans from the Muscatatuck Group, when compared with the occurrence of similar taxa from the correlative strata in the midwestern United States, are quite parallel to the established conodont zones. The lowest occurrence of Alpenachitina eisenacki, Angochitina callawayensis, and Eisenackitina inflata in the lowermost rocks of the Muscatatuck Group is in the Icriodus lateriscrescens robustus Zone, which is early Eifelian in age. Ancryochitina hamiltonensis in association with A. cf. A. spinosa and Hoegisphaera glabra characterizes the upper part of the Muscatatuck rocks, and the occurrence of those chitinozoans ranges from the upper part of the late Eifelian I. Angustus Zone into the early Givetian I. Lateriscrescens latericrescens Zone.
Wright, R. P. 1980, Middle Devonian Chitinozoa of Indiana: Indiana Geological Survey Special Report 18, 24 p., 2 fig., 5 pl.
You may also like:
Can't find what you're looking for? Feel free to contact us directly:
Publication Sales Office
Indiana Geological and Water Survey
420 N. Walnut St.
Bloomington, IN 47404
IGS Return Policy
All sales are final. Materials may not be returned after they have been accepted by the customer. Any discrepencies in mail orders must be reported to IGWS within 10 days of receipt of order.
The Indiana Geological and Water Survey will refund the purchase price and sales tax of products if returned with the original sales receipt within 10 days of receipt of order. Refunds will be issued with the same method of payment as indicated on the original receipt except for cash purchases, which will be refunded by check. Items must be returned in the same condition as purchased. Refunds on digital products and services are not allowed, except for defective media such as CD-ROMs, flash drives, and so on. The customer is responsible for paying shipping costs to return items.