Isorthis-Microsphaeridiorhynchus nucula Comm., Much Wenlock Lst. (Silurian of the United Kingdom)

Where: Wales, United Kingdom (51.7° N, 2.9° W: paleocoordinates 29.2° S, 13.3° W)

• coordinate based on political unit

• local area-level geographic resolution

When: Colonograptus ludensis graptolite zone, Much Wenlock Formation, Homerian (430.5 - 427.4 Ma)

• upper parts of Much Wenlock Lst.

• member-level stratigraphic resolution

Environment/lithology: marine; shelly/skeletal wackestone and silty mudstone

• "..rhynchonellids commonly articulated by that of dalmanellids varies. Lithofacies shows no signs of current activity and is interp. to be relatiely deep water, low energy deposit. Possibly BA 3."
• "...found in nodula limestone lithofacies. Brachiopods occur in elongate nodules surrounded by parallel laminated silty mudstone.

•From Ratcliffe 1991 (ref. 6688): facies is composed of discontinuous beds and nodules of carbonate mudstone, skeletal wackestone or skeletal packstone, separated by varying proportions of silty mudstone, which can form 20-90% of rock volume.

Size class: macrofossils

Primary reference: K. T. Ratcliffe. 1999. Brachiopod assemblages from the Much Wenlock Limestone Formation of England and Wales. In A. J. Boucot and J. D. Lawson (eds.), Paleocommunities--a case study from the Silurian and Lower Devonian 399-407 [M. Foote/M. Foote/M. Foote]more details

Purpose of describing collection: paleoecologic analysis

PaleoDB collection 23287: authorized by Michael Foote, entered by Michael Foote on 11.07.2002

Creative Commons license: CC BY (attribution)

Taxonomic list

• Only brachiopods are studied thoroughly, but non-brachiopod elements are said to be virtually absesnt.
Show authors, comments, and common names
Strophomenata
 Orthotetida - Chilidiopsidae
"Coolinia sp." = Fardenia (Coolinia)
"Coolinia sp." = Fardenia (Coolinia) Bancroft 1949
 Strophomenida - Strophochonetidae
Protochonetes minimus
Protochonetes minimus Sowerby 1839
 Strophomenida - Strophodontidae
Pholidostrophia sp.
Pholidostrophia sp. Hall and Clarke 1892
 Strophomenida - Amphistrophiidae
Amphistrophia sp.
Amphistrophia sp. Hall and Clarke 1892
 Strophomenida - Rafinesquinidae
Leptaena sp.
Leptaena sp. Dalman 1828
Rhynchonellata
 Spiriferida - Delthyrididae
Howellella elegans
Howellella elegans Muir-Wood 1925
 Spiriferida - Cyrtiidae
Eospirifer sp.
Eospirifer sp. Schuchert 1913
 Athyridida - Meristellidae
Whitfieldella sp.
Whitfieldella sp. Hall and Clarke 1893
 Atrypida - Glassiidae
Glassia sp.
Glassia sp. Davidson 1881
genus name in quotes
 Atrypida - Atrypidae
Atrypidae indet., Atrypa reticularis
Atrypidae indet. Gill 1871
ribbed atrypid
Atrypa reticularis Linnaeus 1758
 Rhynchonellida - Trigonirhynchiidae
Microsphaeridiorhynchus nucula, Rhynchotreta sp.
Rhynchotreta sp. Hall 1879
 Rhynchonellida - Hebetoechiidae
Sphaerirhynchia wilsoni
Sphaerirhynchia wilsoni de Sowerby 1816
 Orthida - Rhipidomellidae
Dalejina sp.
Dalejina sp. Havlicek 1953
[entered as Dalejiina sp.]
 Orthida - Dalmanellidae
Resserella sp., Isorthis spp.
Resserella sp. Bancroft 1928
Isorthis spp. Kozlowski 1929