Beartooth Butte Formation

The Beartooth Butte Formation is a geologic formation in Wyoming. It preserves fossils dating back to the Devonian period.

Description
The formation contains a basal limestone conglomerate overlain by evenly bedded red or gray limestones (more accurately, limy mudstones) and calcareous shales. It is a lenticular, channel-fill deposit which is some 2500 ft wide and 250 ft thick at maximum. Most collections are from the talus slope. Stable oxygen and isotope data (Poulson in Fiorillo, 2000) indicate that the Beartooth Butte Formation was deposited in an estuarine environment, with the Cottonwood Canyon section being slightly less saline than the type section.

Fossil content
The following fossils have been reported from the formation:


 * Fish


 * Allocryptaspis ellipticus
 * A. flabelliformis
 * Anarthraspis chamberlini
 * A. montanus
 * Bryantolepis brachycephalus
 * B. cristatus
 * Bryantolepis major
 * B. obscurus
 * Bulbocanthus rugosus
 * Cardipeltis bryanti
 * C. richardoni
 * Cosmaspis transversa
 * Lampraspis tuberculata
 * Machaeracanthus minor
 * Onchus penetrans
 * O. peracutus
 * Protaspis brevispina
 * P. mcgrewi
 * Uranolophus wyomingensis
 * Aethaspis sp.
 * Cephalaspis sp.
 * Simblaspis sp.


 * Arthropods
 * Acanthoscorpio mucronatus
 * Branchioscorpio richardsoni
 * Hydroscorpius denisoni
 * Praearcturus sp.


 * Flora
 * Psilophyton wyomingense
 * Drepanophycus devonicus
 * Euphyllophytina sp.
 * Gosslingia sp.


 * Invertebrates
 * Brachiopoda indet.