Trotland farm, Hølonda, siltstone block (Ordovician of Norway)

Where: Trøndelag, Norway (63.1° N, 10.0° E: paleocoordinates 31.5° S, 10.5° W)

• coordinate estimated from map

When: Didymograptus bifidus graptolite zone, Hølonda Formation, Early/Lower Llanvirn (466.0 - 463.5 Ma)

• Was Whiterockian-Llanvirn. However, Bergström (1979) notes that this is equivalent to the Anomalorthis zone of western North America. The fauna is more North American than Baltic.

• formation-level stratigraphic resolution

Environment/lithology: marine; siltstone

• "The block itself originally consisted of two parts, one more fossiliferous than the other, separated by a bedding plane. We split the two apart with difficulty and collected the more fossiliferous part. The original block was sharpedged and irregular in shape but of general ellipsoidal dimensions, approximately l m long, 30 cm wide, and10 cm high.

•The fossiliferous rock might be termed a silty argillite."

• The fresh rock is is medium gray, and has a yellowish-brown weathered rind about 4 cm thick at one end. Bedding is shown by layers of contrasting carbonate content and is irregular (Fig. 3). Cleavage affords easier parting than bedding, which it intersects at about 40°.

Size classes: macrofossils, mesofossils

Primary reference: R. B. Neuman and D. L. Bruton. 1974. Early Middle Ordovician fossils from the Hølonda area, Trondheim Region, Norway. Norsk Geologisk Tidsskrift 54:69-115 [B. Kröger/B. Kröger]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 191062: authorized by Björn Kröger, entered by Björn Kröger on 08.01.2018

Creative Commons license: CC BY (attribution)

Taxonomic list

unclassified
  -
Trilobita
 Phacopida - Pterygometopidae
Calyptaulax sp. Cooper 1930 trilobite
 Phacopida - Cheiruridae
Sphaerocoryphe sp. Angelin 1854 trilobite
 Proetida - Bathyuridae
Goniotelina broeggeri Strand 1932 trilobite
Strophomenata
 Strophomenida - Syndielasmatidae
 Strophomenida - Taffiidae
Aporthophyla stoermeri Neuman and Bruton 1974
 Strophomenida - Strophomenidae
Trotlandella loki Neuman and Bruton 1974
Rhynchonellata
 Orthida - Orthidae
Trondorthis strandi Neuman and Bruton 1974
Rostroconchia
 Conocardiida - Eopteriidae
Euchasma sp. Billings 1865
Bivalvia
 Nuculida - Cardiolariidae
Deceptrix sp. Fuchs 1919 clam
Gastropoda
 Trochonematoidea - Lophospiridae
"Loxoplocus (Lophospira) sp." = Lophospira
"Loxoplocus (Lophospira) sp." = Lophospira Whitfield 1886 snail
 Euomphalina - Ophiletidae
Lytospira sp. Koken 1896 snail
 Bellerophontida - Plectonotidae
 Bellerophontida - Bucaniidae
Phragmolites sp. Conrad 1838 snail
Rhombifera
 Glyptocystitoida - Macrocystellidae
Macrocystella sp. Callaway 1877
 Glyptocystitoida - Cheirocrinidae
Cheirocrinus sp. Eichwald 1856