Bjørkåsholmen, Asker - Gamma (Ordovician of Norway)

Also known as Was: Bjorkasholmen (Ceratopyge) Fm., Oslo Region, Norway

Where: Oslo, Norway (59.1° N, 11.2° E: paleocoordinates 38.9° S, 16.7° W)

• local area-level geographic resolution

When: Apatokephalus serratus trilobite zone, Bjorkasholmen Formation, Varangu (485.4 - 484.5 Ma)

• Kiaerograptus supremus graptolite zone. Was listed as Ceratopyge 3a

• member-level stratigraphic resolution

Environment/lithology: offshore shelf; lithified conglomerate

• Mainly pale weathering nodular limestone

Size class: macrofossils

Primary reference: G. Henningsmoen. 1959. Rare Tremadocian trilobites from Norway. Norsk Geologiske Tidsskrift 39:153-174 [A. Miller/P. Novack-Gottshall/A. Clement]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 3183: authorized by Arnold Miller, entered by Phil Novack-Gottshall on 27.07.1999, edited by Pete Wagner

Creative Commons license: CC BY (attribution)

Taxonomic list

• Trilobite systematics. Needs to be divided first into alpha, beta & gamma portions of Certopyge "member." Should just be replaced with Ebbestad's (1999) monograph.
Show authors, comments, and common names
Gastropoda
 Bellerophontida - Bucanellidae
Sinuitella norvegica2
Sinuitella norvegica2 Brøgger 1882 snail
Artiopoda
 Agnostida - Metagnostidae
"Trinodus mobergi" = Arthrorhachis mobergi, Geragnostus sidenbladhi, Geragnostus crassus
"Trinodus mobergi" = Arthrorhachis mobergi Tjernvik 1956
Geragnostus crassus Tjernvik 1956
Trilobita
 Ptychopariida - Shumardiidae
"Shumardia pusilla" = Conophrys pusilla
"Shumardia pusilla" = Conophrys pusilla Sars 1835 trilobite
 Asaphida - Remopleurididae
Apatokephalus serratus
Apatokephalus serratus Boeck 1838 trilobite
 Asaphida - Ceratopygidae
Ceratopyge acicularis1, Tropidopyge broeggeri
Ceratopyge acicularis1 trilobite
Ceratopyge forficula acicularis
 Asaphida - Asaphidae
Niobe insignis, "Niobella obsoleta" = Niobe (Niobella) obsoleta, Promegalaspides (Borogothus) intactus
Niobe insignis trilobite
"Niobella obsoleta" = Niobe (Niobella) obsoleta Linnarsson 1869 trilobite
Promegalaspides (Borogothus) intactus Moberg and Segerberg 1906 trilobite
 Asaphida - Nileidae
Nileus limbatus, Symphysurus angustatus, Varvia longicauda
Nileus limbatus trilobite
Symphysurus angustatus Sars and Boeck 1838 trilobite
 Asaphida - Hungaiidae
Dikelokephalina dicraeura
 Trinucleida - Alsataspididae
Falanaspis aliena, Orometopus elatifrons, Pagometopus gibbus n. gen. n. sp.
Falanaspis aliena Tjernvik 1956 trilobite
Pagometopus gibbus n. gen. n. sp. trilobite
 Harpetida - Harpididae
Harpides rugosus
 Phacopida - Cheiruridae
Pliomeroides primigenus, Parapilekia speciosa
 Olenida - Olenidae
Hypermecaspis rugosa, "Triarthrus angelini" = Bienvillia angelini, Parabolinella lata, Saltaspis sp.
"Triarthrus angelini" = Bienvillia angelini Linnarsson 1869 trilobite
Saltaspis sp. Harrington and Leanza 1952 trilobite
 Olenida - Eulomidae
Euloma ornatum
Euloma ornatum trilobite
1Ebbestad 1999; 2Yochelson 1962