Fort Cassin, VT, Fort Cassin Formation: Cassinian, Vermont
List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
Cephalopoda
- Ellesmerocerida
- Ellesmeroceratidae
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Cyrtoceras acinacellum
Whitfield 1886
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1 specimen | |||||||||
(Cyrtoceras) acinacellum | ||||||||||
= Bassleroceras acinacellum
Whitfield 1886
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Kröger and Landing 2009 | |||||||||
Cephalopoda
- Ellesmerocerida
- Protocycloceratidae
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Cyptendoceras ruedemanni
Ulrich and Foerste 1936
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Kröger and Landing 2009 | 2 specimens | ||||||||
Protocycloceras geronticum
Ulrich et al. 1944
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Kröger and Landing 2009 | 1 specimen | ||||||||
Protocycloceras whitfieldi
Ruedemann 1906
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7 specimens | |||||||||
= Protocycloceras lamarcki
Billings 1859
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Kröger and Landing 2009 | |||||||||
Cephalopoda
- Ellesmerocerida
- Rudolfoceratidae
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Orygoceras cornuoryx
(Whitfield 1886)
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26 specimens | |||||||||
recombined as Rudolfoceras cornuoryx | ||||||||||
Orygoceras cornu-oryx | ||||||||||
Cephalopoda
- Bassleroceratidae
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Cyrtoceras confertissimum
Whitfield 1936
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2 specimens | |||||||||
(Cyrtoceras) confertissimum | ||||||||||
= Lawrenceoceras confertissimum
Whitfield 1886
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Kröger and Landing 2009 | |||||||||
Lawrenceoceras breve
(Ulrich et al. 1944)
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Kröger and Landing 2009 | 1 specimen | ||||||||
Cephalopoda
- Cyclostomiceratidae
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Cyclostomiceras cassinense
(Whitfield 1886)
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6 specimens | |||||||||
Cyclostomiceras minimum
(Whitfield 1886)
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11 specimens | |||||||||
Cephalopoda
- Tarphycerida
- Tarphyceratidae
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Pionoceras vokesi
Ulrich et al. 1942
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Kröger and Landing 2009 | 1 specimen | ||||||||
Eurystomites kelloggi
(Whitfield 1886)
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6 specimens | |||||||||
Eurystomites rotundus
Hyatt 1894
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3 specimens | |||||||||
= Eurystomites kelloggi
Whitfield 1886
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Kröger and Landing 2009 | |||||||||
Tarphyceras perkinsi
(Whitfield 1897)
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2 specimens | |||||||||
Campbelloceras hyatti
Ulrich et al. 1942
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Kröger and Landing 2009 | 1 specimen | ||||||||
Eurystomites virginianus
Hyatt 1894
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= Campbelloceras virginianus
Hyatt 1894
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Kröger and Landing 2009 | |||||||||
Tarphyceras seelyi
(Whitfield 1886)
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8 specimens | |||||||||
= Centrotarphyceras seelyi
Whitfield 1886
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Kröger and Landing 2009 | |||||||||
Tarphyceras champlainense
(Whitfield 1886)
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= Centrotarphyceras seelyi
Whitfield 1886
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Kröger and Landing 2009 | |||||||||
Centrotarphyceras subundosum
Ulrich et al. 1942
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Kröger and Landing 2009 | 2 specimens | ||||||||
Cephalopoda
- Tarphycerida
- Trocholitidae
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Schroederoceras eatoni
(Whitfield 1886)
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7 specimens | |||||||||
recombined as Curtoceras eatoni | ||||||||||
Schroederoceras cassinense
Whitfield 1886
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synonym of Curtoceras eatoni | ||||||||||
Trocholitoceras walcotti
Hyatt 1894
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1 specimen | |||||||||
Trocholites internestriatus
(Whitfield 1886)
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4 specimens | |||||||||
Cephalopoda
- Endocerida
- Proterocameroceratidae
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Cameroceras brainerdi
(Whitfield 1886)
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10 specimens | |||||||||
= Proterocameroceras brainerdi
Whitfield 1886
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Kröger and Landing 2009 | |||||||||
Endoceras montrealense
(Ruedemann 1906)
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3 specimens | |||||||||
= Proterocameroceras brainerdi
Whitfield 1886
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Kröger and Landing 2009 | |||||||||
Cephalopoda
- Bisonocerida
- Piloceratidae
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Piloceras explanator
Whitfield 1886
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8 specimens | |||||||||
recombined as Cassinoceras wortheni | ||||||||||
Cassinoceras explanator
(Billings 1865)
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Ulrich et al. 1943 | |||||||||
Piloceras wortheni | ||||||||||
Cassinoceras grande
Ulrich and Foerste 1943
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Kröger and Landing 2009 | 4 specimens | ||||||||
recombined as Expandocassinoceras grande | ||||||||||
Cephalopoda
- Orthocerida
- Baltoceratidae
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Cyrtobaltoceras gracile
Flower 1964
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Kröger and Landing 2009 | 1 specimen | ||||||||
see common names |
Geography
Country: | United States | State/province: | Vermont | County: | Addison |
Coordinates: | 44.2° North, 73.2° West (view map) | ||||
Paleocoordinates: | 30.6° South, 61.2° West | ||||
Basis of coordinate: | based on nearby landmark | ||||
Geographic resolution: | outcrop |
Time
Period: | Ordovician | ||
10 m.y. bin: | Ordovician 2 | ||
Key time interval: | Cassinian | Conodont zone: | Oepikodus communis - Reuterodontus andinus |
Age range of interval: | 478.60000 - 468.10000 m.y. ago |
Stratigraphy
Geological group: | Beekmantown | Formation: | Fort Cassin | Member: | Sciota |
Stratigraphic resolution: | formation |
Lithology and environment
Primary lithology: | lithified calcareous,carbonaceous "limestone" | ||
Lithology description: Details of the divisions at each of the localities from which each specimen listed are not given, thus I will give a complete description of lithologies summarized by Ruedemann for the formation at two different localities. “Section of the Beekmantown beds at Valcour in ascending order: A1 is a four foot bed of hard bluish gray, gritty dolomite. Strike, n.30 e.; dip, 5˚ s.e. A2 begins 100 feet north of end of A1. 3 feet. Bluish gray dolomite, with lenses of lighter dolomite; the latter very fossiliferous. A3 exposed about 300 feet north of A2. 6 feet. This division is shaly at the base, compact, gray or black at the middle and shaly and black at the top, the whole weathering yellowish. The gray portion is a mass of fossil fragments derived from crinoids, trilobites, cephalopods, gastropods and brachiopods, and contains small rounded pebbles or concretions. The shaly portion at the top is a valuable depository of cephalopods (nautilicones and orthocerecones). A4 is a mass of rocks exposed for a considerable distance along the shore and consisting of an irregular series of beds or gray brown and bluish blake sandy dolomite with thin intercalations of very fossiliferous limestone. The surfaces of the strata are characteristically marked by an entagled mass of vermiform ridges suggesting fucoids, and by channels, suchas are formed on sandy beaches at low tide. These channels are filled with a bluish gray limestone, contrasting with the sandy rocks and choked with fossils, specially orthoceracones, which lie in the longitudinal direction of the channels. The channels run slightly north of east. Systems of large ripple marks extend over some of the rock surfaces. Thickness not obtained. A5, rock exposed on north side of Sibley point, exposures beginning behind Pacno’s barn, where a dolomite bed 4 ½ feet thick rests upon A4. This is followed by a cross-bedded impure limestone containing numerous cephalopods (nautilicones) and other fossils. A6, 6 feet of a purer, blue limestone, which is irregularly bedded and contains seams of black shale. A7, a heavy bed (7 feet) of blue sandy limestone, weathering yellow, exposed at top of bank, at east end of Sibley point. A8, separated by a concealed interval from A7 and consists of about 25 feet of heavy bluish limestone strata, which weather gray, are barren and contain some geodes. This bed ends at the Valcour dock. Strike n. 40 w.; dip, 15˚ s.w.” “Section at East Shoreham in ascending order: Division A. Dark iron gray magnesian limestone, usually in beds one or two feet in thickness more or less siliceous, in some beds even approaching a sandstone, Fossils none. Thickness 310 feet. Division B. Dove colored limestone, intermingled with light gray dolomite, in massive beds. Fossils: Orthoceras primigenium, Cryptozoön steeli. Thickness 295 feet. Division C. In succession gray, thin bedded, fine grained calciferous sandstone; magnesian limestone in thick beds, weathering drab; sandstones, sometimes pure and firm, but usually calciferous or dolomitic; magnesian limestone like no. 2, frequently containing patches of black chert. Fossils, none, except Scolithos minutus Wing. Thikness 350 feet. Division D. In seccession blue limestone, in beds one or two feet thick, breaking with a flinty fracture; the weathered surface with a rough curdled appearance; drab and brown magnesian limestone; sandy limestone in thin beds; blue limestone in thin bands. Fossils: Ophieta complanata, Maclurea affinis, Lituites eatoni, Asaphus canalis and species of Cryptozoön, Bathyurus, Maclurea, Murchisoni, Orthocera, Cyrtoceras. Thickness 375 feet. Division E. Fine grained magnesian limestone in beds one or two feet in thickness, weathering drab, yellowish or brown. Fossils: Bucania tripla, Murchisonia confuse, Bathyurus extans? var., Primitia seelyi and species of Lingula, Maclurea?, Murchisonia, Orthosceras, Bathyurus, Cheirurus?, and encrinal columns. Thickness 470 feet.” “Since we can do no better than base our future stratigraphic work on the larger lithologic divisions recognized by Brainerd and Seely in the Beekmantown formation at East shore ham Vt. And in the Chazy formation at Chazy village, we refer the fossils obtained at other places than the Valcour shore provisionally to those divisions.” | |||
Environment: | shallow subtidal indet. | Tectonic setting: | passive margin |
Taphonomy
Modes of preservation: | recrystallized,original aragonite,replaced with calcite |
Size of fossils: | macrofossils |
Preservation of anatomical detail: | good |
Abundance in sediment: | abundant |
Spatial resolution: | autochthonous |
Collection methods and comments
Reason for describing collection: | taxonomic analysis |
Metadata
Database number: | 42793 | ||
Authorizer: | P. Wagner, B. Kröger | Enterer: | K. Koverman, B. Kröger |
Modifier: | B. Kröger | Research group: | marine invertebrate |
Created: | 2004-08-05 11:34:19 | Last modified: | 2017-10-09 07:45:07 |
Access level: | the public | Released: | 2004-08-05 11:34:19 |
Creative Commons license: | CC BY |
Reference information
Primary reference:
11371. | 1% | R. Ruedemann. 1906. Cephalopoda of the Beekmantown and Chazy formations of the Champlain Basin. Bulletin of the New York State Museum, Paleontology 14:389-611 [P. Wagner/K. Koverman/M. Uhen] |
Secondary references:
30173 | B. Kröger and E. Landing. 2009. Cephalopods and Paleoenvironments of the Fort Cassin Formation (Upper Lower Ordovician), eastern New York and adjacent Vermont. Journal of Paleontology 83(5):664-693 [B. Kröger/B. Kröger] | |
30180 | E. O. Ulrich, A. F. Foerste, A. K. Miller and W. M. Furnish. 1942. Ozarkian and Canadian cephalopods, Part I: Nautilicones. Geological Society of America Special Papers 37:1-157 [B. Kröger/B. Kröger/B. Kröger] | |
13254 | E. O. Ulrich, A. F. Foerste, and A.K. Miller. 1943. Ozarkian and Canadian cephalopods. Part II, Brevicones. Geological Society of America Special Papers 49:1-240 [P. Wagner/P. Wagner/M. Uhen] |