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Reference
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| Title: |
Report on Referred Fossils
,
1979
(07/23)
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Among the ammonites listed on this report, Phylloceras (Partschiceras) sp. B occurs at three localities. It has been collected previously only on the Alaska Peninisula and only at Mesozoic localities 11359 (Chignik D-1 quad.) and 29253 (Iliamna A-3 quad.) At Mesozoic loc. 29253 at Kamishak Bay it was associated with Buchia mosquensis (von Buch), a species of late Kimmeridgian and early Tithonian age.
The ammonite from loc. M6914 listed as Discosphinctes? sp. juv. is probably an immature form of Discosphinctes (See Treatise by Arkell and others, 1957, p. L320, L322) of late Oxfordian age. It is common in the Tethyan region but has been found as far north as California (See Prof. Paper 374-D, p. D5, D7, D13, D23, pl. 3, figs. 1-12). The adult form of Discosphinctes differs from the immature form by developing more secondary ribs per primary rib. It is probably too late to include a picture of the ammonite from locality M6914 in my paper on Upper Jurassic Ammonites From Alaska but that possibility will be considered.
I notice that none of the ammonite collections that you made on the Alaska Peninsula in 1977 include any specimens of Buchia. Such should be included in the future if Buchia occurs in, or within a few feet of a bed containing ammonites. Also, a collection of buchias from above a bed containing some ammonites might be useful as additional age evidence. In this regard, please note that Discosphinctes in California occurs in beds containing Buchia concentrica and has never been found associated with B. rugosa, or B. mosquensis. |
| Report by: |
Ralph W. Imlay
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| Referred by: |
Robert L. Detterman
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| | Age: | No Data |
| Formation: | Naknek Formation |
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| Occurrence(s) |
| No. |
Group |
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Name |
Qty |
Notes |
| 1 |
Ammonoids |
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Ammonite fraqment |
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