83RB9, south flank of Limestone Mountain: Early/Lower Emsian, Alaska

List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
Stromatoporoidea - Amphiporida - Amphiporidae
Amphipora sp. Schulz 1883
Frýda and Blodgett 2004
Demospongiae
Medfraspongia tubulara Rigby et al. 2009
Rigby et al. 2009
Anthozoa
Tabulata indet. (Milne-Edwards and Haime 1850)
Rigby et al. 2009
Anthozoa - Rugosa
Rugosa indet. Milne-Edwards and Haime 1850
Rigby et al. 2009
Tentaculitida
Tentaculitida indet. Ljaschenko 1955
Rigby et al. 2009
unclassified
Brachiopoda indet. Cuvier 1805
Rigby et al. 2009
Gastropoda - Kuskokwimiidae
Kuskokwimia moorei n. gen., n. sp. Frýda and Blodgett 2001
Frýda and Blodgett 2001
Gastropoda - Murchisoniina - Murchisoniidae
Farewellia heidelbergerae n. gen., n. sp. Frýda and Blodgett 2004
Frýda and Blodgett 2004 4 specimens
Gastropoda - Murchisoniina - Palaeozygopleuridae
Palaeozygopleura (Rhenozyga) reifenstuhli n. sp. Frýda and Blodgett 2004
Frýda and Blodgett 2004 5 specimens
recombined as Rhenozyga reifenstuhli
Medfrazyga clauticae n. gen., n. sp. Frýda and Blodgett 2004
Frýda and Blodgett 2004 4 specimens
Gastropoda - Murchisoniina - Soleniscidae
Nanochilina gubanovi n. sp. Frýda and Blodgett 2004
Frýda and Blodgett 2004 3 specimens
Alaskacirrus bandeli n. gen., n. sp. Frýda and Blodgett 1998
Frýda and Blodgett 1998 15 specimens
Gastropoda - Murchisoniina - Gosseletinidae
Balbinipleura krawczynskii n. sp. Frýda and Blodgett 2004
Frýda and Blodgett 2004 1 specimen
Arctozone cooki n. gen., n. sp. Frýda and Blodgett 2004
Frýda and Blodgett 2004 4 specimens
Chlupacispira spinosa n. gen., n. sp. Blodgett and Rohr 1989
3 specimens
Gastropoda - Murchisoniina - Porcelliidae
Alaskiella medfraensis n. gen., n. sp. Frýda and Blodgett 1998
Frýda and Blodgett 1998 9 specimens
Quadricarina (? Quadricarina) noklebergi n. sp. Frýda and Blodgett 2004
Frýda and Blodgett 2004 5 specimens
recombined as Quadricarina noklebergi
Gastropoda - Euomphalina - Pseudophoridae
Decorospira lepaini n. sp. Frýda and Blodgett 2004
Frýda and Blodgett 2004 3 specimens
? Decorospira minutula n. sp. Frýda and Blodgett 2004
Frýda and Blodgett 2004 1 specimen
Gastropoda - Euomphalina - Euomphalidae
Euomphalopterus sp. Roemer 1876
Frýda and Blodgett 1998
Straparollus (Eleutherospira) medfraensis Blodgett and Johnson 1992
Blodgett and Johnson 1992
recombined as Eleutherospira medfraensis
Scaphopoda
Scaphopoda indet. Bronn 1862
Rigby et al. 2009
Bivalvia
Bivalvia indet. Linnaeus 1758
Rigby et al. 2009
Cephalopoda
Cephalopoda indet. Cuvier 1797
Rigby et al. 2009
Ammonoidea indet. (Zittel 1884)
Rigby et al. 2009
Ostracoda - Leperditicopida
? Eomoelleritia sp. Abushik 1972
Ostracoda - Platycopida - Miltonellidae
? Libumella sp. Rozhdestvenskaya 1959
Ostracoda - Palaeocopida
Nezamyslia aff. jucunda
Polenova 1974
? Scaphina sp.
Ostracoda - Palaeocopida - Beyrichiidae
Beyrichia (Scabribeyrichia) churkini
Berdan & Copeland 1973
see common names

Geography
Country:United States State/province:Alaska County:Medfra
Coordinates: 63.3° North, 154.5° West (view map)
Paleocoordinates:2.5° North, 46.0° West
Basis of coordinate:stated in text
Altitude:1700 feet
Geographic resolution:outcrop
Time
Period:Devonian Epoch:Early/Lower Devonian
Stage:Emsian 10 m.y. bin:Devonian 2
Key time interval:Early/Lower Emsian Conodont zone: Polygnathus dehiscens
Age range of interval:407.60000 - 398.30000 m.y. ago
Stratigraphy
Formation:Limestone Mountain
Local section:Limestone Mountain Local bed:13.7 - 15.2 m
Local order:bottom to top
Stratigraphic resolution:bed
Stratigraphy comments: On the basis of regional stratigraphic correlations and faunal composition, the host beds appear to be slightly younger than the earliest Emsian (Polygnathus dehiscens Zone) Soda Creek Limestone (Blodgett et al., 2000).

(This would be Polygantuhs gronbergi/P. excavatus zone, or 406-403.5 Ma on Gradstein et al.)

Note also that "Limestone Mountain" is an informal name.
Lithology and environment
Primary lithology: "limestone"
Lithology description: 1.5 m thick, silicified, richly fossiliferous rubble zone in an unnamed Devonian limestone unit; eurekaensis / delta conodont zones (Fryda & Blodgett 2004).
Environment:carbonate indet.
Geology comments: Transitional biofacies from the more open-marine environment below into the restricted lagoonal facies above.

The dominance of the fauna by a highly diverse assemblage of gastropods, together with the abundance of the tubular stromatoporoid genus Amphipora in underlying and overlying strata, indicates a relatively shallow-water (shallow part of the photic zone), inner carbonate platform environment. (Fryda & Blodgett 2004:111)
Taphonomy
Modes of preservation:replaced with silica
Size of fossils:macrofossils
Collection methods and comments
Collection excludes:some macrofossils,some microfossils
Reason for describing collection:taxonomic analysis
Museum repositories:USNM
Collection method comments: Cobbled together from multiple taxonomy papers
Metadata
Database number:49107
Authorizer:P. Wagner, A. Miller Enterer:P. Wagner, S. Kolbe
Modifier:P. Wagner Research group:marine invertebrate
Created:2005-04-08 15:47:56 Last modified:2016-09-08 20:28:11
Access level:the public Released:2005-04-08 15:47:56
Creative Commons license:CC BY
Reference information

Primary reference:
13130. R. B. Blodgett and D. M. Rohr. 1989. Two new Devonian spine-bearing pleurotomariacean gastropod genera from Alaska. Journal of Paleontology 63(1):47-52 [P. Wagner/P. Wagner/P. Wagner]

Secondary references:

255 R. B. Blodgett and J. G. Johnson. 1992. Early Middle Devonian (Eifelian) Gastropods of Central Nevada. Palaeontographica Abteilung A 222:85-139 [P. Wagner/P. Wagner/P. Wagner]
13129 J. Frýda and R. B. Blodgett. 1998. Two new cirroidean genera (Vetigastropoda, Archaeogastropoda) from the Emsian (late Early Devonian) of Alaska with notes on the Early Phylogeny of Cirroidea. Journal of Paleontology 72(2):265-273 [P. Wagner/P. Wagner/P. Wagner]
13128 J. Frýda and R. B. Blodgett. 2001. The oldest known heterobranch gastropod, Kuskokwimia gen. nov., from the Early Devonian of west-cetnral Alaska, with notes on the early phylogeny of higher gastropods. Bulletin of the Czech Geological Survey 76(1):39-53 [P. Wagner/P. Wagner/P. Wagner]
13132 J. Frýda and R. B. Blodgett. 2004. New Emsian (Late Early Devonian) gastropods from Limestone Mountain, Medfra B-4 Quadrangle, west-central Alaska (Farewell Terrane) and their paleobiogeographic affinities and evolutionary significance. Journal of Paleontology 78(1):111-132 [P. Wagner/P. Wagner/S. Kolbe]
34239 0J. K. Rigby, R. B. Blodgett, and N. K. Anderson. 2009. Emsian (Early Late Devonian) sponges from west-central and south-central Alaska. Journal of Paleontology 83(2):293-298 [A. Miller/S. Kolbe]