Hells Canyon (Triassic of the United States)

Also known as Martin Bridge Limestone

Where: Oregon (45.0° N, 116.0° W: paleocoordinates 19.1° N, 52.4° W)

• coordinate stated in text

• small collection-level geographic resolution

When: Martin Bridge Formation, Lacian (221.5 - 215.6 Ma)

• On a regional scale, the Martin Bridge Limestone can be characterized as a discontinuously preserved Carnian-Norian carbonate unit that occurs in northeastern Oregan and western Idaho. The Martin Bridge overlies the Seven Devils Group in apparent unconformable contact and is in turn stratigraphically overlain by the Late Triassic-Early Jurassic shale and limestone of the Hurwal Fromation.

•JA: from the early Norian Mojsisovicsites kerri Zone

• group of beds-level stratigraphic resolution

Environment/lithology: shallow subtidal; lithified limestone

• Martin Bridge limestone represents a deepening-upward sequence ranging from supratidal carbonate lithofacies, with the silicified shell beds corresponding to the upper part of this sequence.

Size class: macrofossils

Preservation: replaced with silica

Primary reference: C. R. Newton, M. T. Whalen, J. B. Thompson, N. Prins, and D. Delallia. 1987. Systematics and paleoecology of Norian (Late Triassic) bivalves from a tropical island arc: Wallowa Terrane, Oregan. Memoir - Paleontological Society 22:1-83 [D. Bottjer/N. Bonuso/S. Kolbe]more details

Purpose of describing collection: paleoecologic analysis

PaleoDB collection 33294: authorized by David Bottjer, entered by Nicole Bonuso on 24.07.2003, edited by Bethany Allen

Creative Commons license: CC BY (attribution)

Taxonomic list

Bivalvia
 Nuculoida -
"Nuculoida indet." = Nuculida
"Nuculoida indet." = Nuculida Dall 1889 clam
 Arcida - Parallelodontidae
Parallelodon cf. monobensis Nakazawa 1955 clam
 Pectinida - Plicatulidae
Plicatula sp. Lamarck 1801 scallop
Plicatula hekiensis Nakazawa 1955 scallop
 Pectinida - Limidae
Lima spinigera file clam
Antiquilima sp. Cox 1943 file clam
Antiquilima vallieri n. sp. Newton et al. 1987 file clam
Pseudolimea naumanni Kobayashi and Ichikawa 1951 file clam
? Plagiostoma sp. Sowerby 1814 file clam
 Pectinida - Pectinoidae
Pectinidae indet. Wilkes 1810 scallop
cf. Chlamys mojsisovicsi Kobayashi and Ichikawa 1949 scallop
Tosapecten subhiemalis Kiparisova 1940 scallop
Crenamussium concentricum Newton et al. 1987 scallop
Pleuronectites sp. Schlotheim 1820 scallop
 Ostreida - Gryphaeidae
Liostrea newelli Newton et al. 1987 oyster
 Ostreida - Ostreidae
Lopha sp. Röding 1798 oyster
? Lopha sp. Röding 1798 oyster
 Ostreida - Cassianellidae
Cassianella angusta Bittner 1891 oyster
 Ostreida - Pteriidae
? Arcavicula sp. Cox 1964 pearl oyster
 Ostreida - Bakevelliidae
? Gervillia sp. Defrance 1820 oyster
"Gervillia angusta" = Gervillia (Cultriopsis) angusta Munster 1838 oyster
 Myalinida - Mysidiellidae
"Mysidiella cordillerana" = Promysidiella cordillerana, Mysidiella newtonae
"Mysidiella cordillerana" = Promysidiella cordillerana Newton et al. 1987 clam
Mysidiella newtonae Waller and Stanley 2005 clam
 Myalinida - Myalinidae
"Mysidioptera williamsi" = Aviculomyalina williamsi
"Mysidioptera williamsi" = Aviculomyalina williamsi McLearn 1941 clam
 Unionida - Pachycardiidae
Cardinioides josephus Newton et al. 1987 clam
 Trigoniida - Trigoniidae
Minetrigonia sp. Kobayashi and Katayama 1938 clam
 Trigoniida - Myophoriidae
Erugonia canyonensis Newton et al. 1987 clam
 Trigoniida - Myophorelloidae
? Frenguelliella sp. Leanza 1942 clam
 Carditida - Astartidae
Astarte sp. Sowerby 1816 clam
 Carditida - Carditidae
 Cardiida - Palaeocarditidae
Palaeocardita silberlingi n. sp. Newton et al. 1987 clam
 Cardiida - Cardiidae
Septocardia sp. Hall 1877 cockle
 Cardiida - Kalenteridae
Myoconchinae indet. Newell 1957 clam