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, W. P., 1980, Middle Devonian Chitinozoa of Indiana: Indiana Geological Survey Special Report 18, 24 p., 5 pl., 2 figs. doi: 10.5967/s1d8-yt73
You may also like:
Can't find what you're looking for? Feel free to contact us directly:
Indiana Geological and Water Survey
1001 E. 10th St.
Bloomington, IN 47405
IGS Return Policy
- Original sales receipt required.
- Returns accepted within 30 days of purchase date.
- Refund will be issued by the same method of payment as purchased.
- Products must be returned in the same new condition as purchased.
- Refunds on custom orders and digital products are NOT allowed.
- Customers are responsible for paying shipping costs to return products.