These fossils are from the two fossiliferous
beds at the top of the romunderi zone, above rocks containing
meekoceras, and just below the anasibirites beds
see rocks of the Thaynes Group
Churkites noblei Jenks
2007
a very large Churkites
noblei Jenks 2007
These have a higher whorl and sharper venter than other Arctocerids (this may be an artifact of preservation) but the ornamentation of nodes around the umbilicus, longitudinal striae on the venter, and distant ribs are typical of Arctoceras. These were previously assigned herein to Arctoceras tuberculatum (Smith) 1932, however, J. F. Jenks (2007) has found rare but well preserved specimens at Crittenden Springs, Nevada and assigned them to the new taxon. Though his specimens are better preserved these appear to be conspecific. C. noblei is quite common in the Confusion Range.
Some common ammonoids from the Thaynes Group
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