Isorthis-Dalejina Comm., Much Wenlock Lst.: Homerian, United Kingdom

List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
unclassified
Brachiopoda indet. Cuvier 1805
unidentifiable inarticulates
Rhynchonellata - Spiriferida - Delthyrididae
Howellella sp. Kozlowski 1946
Rhynchonellata - Spiriferida - Cyrtinopsidae
Kozlowskiellina sp. Boucot 1958
Rhynchonellata - Atrypida - Glassiidae
Glassia sp. Davidson 1881
genus name in quotes
Rhynchonellata - Atrypida - Atrypidae
Atrypidae indet. Gill 1871
ribbed atrypid
Atrypa sp. Dalman 1828
Rhynchonellata - Orthida - Dalmanellidae
Isorthis spp.
Resserella sp. Bancroft 1928
Rhynchonellata - Orthida - Rhipidomellidae
Dalejina sp. Havlicek 1953
Rhynchonellata - Rhynchonellida - Trigonirhynchiidae
Microsphaeridiorhynchus sp. Sartenaer 1970
Rhynchonellata - Rhynchonellida - Hebetoechiidae
Sphaerirhynchia sp. Cooper and Muir-Wood 1951
Strophomenata - Strophomenida - Strophochonetidae
Protochonetes sp. Muir-Wood 1962
Strophomenata - Strophomenida - Sowerbyellidae
Eoplectodonta sp. Kozlowski 1929
Strophomenata - Strophomenida - Strophodontidae
Pholidostrophia sp. Hall and Clarke 1892
Strophomenata - Strophomenida - Amphistrophiidae
Amphistrophia sp. Hall and Clarke 1892
Strophomenata - Strophomenida - Rafinesquinidae
Leptaena sp. Dalman 1828
Strophomenata - Orthotetida - Chilidiopsidae
Coolinia sp. Bancroft 1949
spelled with current rank as Fardenia (Coolinia)
see common names

Geography
Country:United Kingdom State/province:England
Coordinates: 52.0° North, 2.0° West (view map)
Paleocoordinates:28.9° South, 12.7° West
Basis of coordinate:based on political unit
Geographic resolution:basin
Time
Period:Silurian Epoch:Wenlock
Stage:Homerian 10 m.y. bin:Silurian 2
Key time interval:Homerian
Age range of interval:430.50000 - 427.40000 m.y. ago
Stratigraphy
Formation:Much Wenlock
Stratigraphic resolution:formation
Stratigraphy comments: ludensis, lundgreni, and nassa zones
Lithology and environment
Primary lithology: silty mudstone
Secondary lithology: lime mudstone
Includes fossils?Y
Lithology description: "...from interbedded limestone and silty mudstone lithofacies and nodular limestone lithofacies, but only from the algillaceous (silty mudstone) parts of each lithofacies. Mudstones commonly parallel laminated, when not strongly bioturbated, and show no evidence of current. Shells occur scattered throughout silty mudstones, or less commonly as coquinas of disarticulated shells" From Ratcliffe 1991 (ref. 6688): nodular 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. From Ratcliffe 1991 (ref. 6688): Interbedded facies is composed of varying proportions of continuous limestone beds separated by silty mudstone. Lst beds compositionally variable; carb. mudstones, skeletal wackestones, skeletal packstones, crinoidal grainstones and peloidal grainstones all common. .Wave rippled bedding surfaces and symmetrical cross lamination common. Small coral/stromatop. bioherms occur.
Environment:marine indet.
Geology comments: Suggests silty mudstone is the background sedimentation, with limestone reflecting occasional increase in carbonate production. Low energy sediments. Paucity of fossils pluse bioturbation indicates soupy sediment, with limited atttachment for pedunculate forms. Possibly BA 3."
Taphonomy
Modes of preservation:body
Size of fossils:macrofossils
Collection methods and comments
Collection excludes:some macrofossils
Reason for describing collection:paleoecologic analysis
Taxonomic list comments:Only brachiopods are studied thoroughly.
Metadata
Database number:23293
Authorizer:M. Foote Enterer:M. Foote
Modifier:M. Uhen Research group:marine invertebrate
Created:2002-07-11 13:21:58 Last modified:2018-11-26 18:24:30
Access level:the public Released:2002-07-11 13:21:58
Creative Commons license:CC BY
Reference information

Primary reference:
6676. 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]