Fauna i, Section AV2, Whittaker Fm., Mackenzie Mts. (Silurian to of Canada)

Where: Northwest Territories, Canada (62.4° N, 127.0° W: paleocoordinates 7.9° N, 52.9° W)

• coordinate estimated from map

• outcrop-level geographic resolution

When: Pterospathodus amorphognathoides zone, Whittaker Formation, Llandovery to Llandovery (443.4 - 427.4 Ma)

• Zonation based on conodonts present in AV sections 1, 2, and 4. (AV 3 and DR sections correlated with these on basis of trilobite faunal assemblages.)

• group of beds-level stratigraphic resolution

Environment/lithology: basinal (); shale

• "The strata assigned to the Whittaker Formation in these sections are largely deeper water platform margin or upper slope limestones and shales." Grand Cycle 2-3 transition.

•SEP environmental call: this is sort of tough to fit into given classification because of the hard-and-fast distinction made between carbonate and siliciclastic environments. Basically, this sample comes from buff brown shales that appear to be just above the base of the MFS in this basin and it may even be from the MFS itself. I have classified this sample in the siliciclastic framework, but it is within a carbonate-dominated system

• Whittaker Fm. in general: "Beneath a distinctive buff-brown coloured shale unit, assigned to the base of the Delorme Fm., the strata consist of interbedded argillaceous limestones, calcareous shales, and cherty dolomites...The more carbonate-rich horizons contain rich silicified trilobite, conodont, and ostracode faunas. They also contain sparser coral, bryozoanb, brachiopod, mollusc, and other invertebrate faunas..."

•SEP adjusted lithofacies to match sample location in section as indicated on page 7 of primary ref.

Preservation: replaced with silica

Primary reference: B. D. E. Chatterton and D. G. Perry. 1983. Silicified Silurian odontopleurid trilobites from the Mackenzie Mountains. Palaeontographica Canadiana 1:1-55 [M. Foote/M. Foote/M. Foote]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 26041: authorized by Michael Foote, entered by Michael Foote on 01.10.2002

Creative Commons license: CC BY (attribution)

Taxonomic list

unclassified
  -
Rhynchonellata
 Spiriferida - Cyrtiidae
Hedeina sp.2 Boucot 1957
 Spiriferida - Reticulariidae
Spirinella struszi2 Zhang 1989
 Athyridida - Meristellidae
Whitfieldella sulcatina2 Jin et al. 1993
 Atrypida - Septatrypidae
Atrypoidea linguata2 von Buch 1834
Septatrypa zelia2 Barrande 1879
 Atrypida - Atrypinidae
Gracianella lissumbra2 Johnson and Boucot 1967
 Atrypida - Atrypidae
Atrypa (Gotatrypa) variabilis2 Johnson et al. 1976
 Orthida - Hesperorthidae
Hesperorthis avalanchensis2 Jin and Chatterton 1997
 Orthida - Dicoelosiidae
Dicoelosia parvifrons2 Johnson et al. 1976
Trilobita
 Odontopleurida - Odontopleuridae
 Phacopida - Cheiruridae
"Youngia brennardi" = Parayoungia brennardi1 Chatterton and Perry 1984 trilobite
Contracheirurus sp.1 Chatterton and Perry 1984 trilobite
Sphaerexochus dimorphus1 Whittington and Evitt 1953 trilobite
Deiphon sp.1 Barrande 1846 trilobite
Youngia steineri1 Chatterton and Perry 1984 trilobite