Dalmanella-Eospirigerina Community, Mosalem Formation, Jackson Co., Iowa (Silurian of the United States)

Where: Iowa (42.3° N, 90.4° W: paleocoordinates 19.8° S, 57.6° W)

• coordinate based on nearby landmark

• small collection-level geographic resolution

When: Mosalem Formation, Rhuddanian (443.4 - 440.8 Ma)

• Upper Mosalem Formation (formerly 'Edgewood Formation').

• formation-level stratigraphic resolution

Environment/lithology: lagoonal or restricted shallow subtidal; burrowed, dolomitic, argillaceous lime mudstone and shale

• "shells commonly disarticulated but not abraded...Predominance of mud suggests relatively quiet conditions...but presence of ripple cross laminations and argillaceous laminae indicate episodic bottom current activity...scarcity of skeletal debris through much of Mosalem may indicate...possibly low oxygen (organic carbon films common)...[Relations with other communities]suggest BA 2."

•

•SEP environmental call based on given description and same vol. page 807.

• "Argillaceous carbonate mudstones (dolomitized) with shaley partings...horizontal Chondrites burrows...skeletal debris scattered (partly silicified)..."

Collection methods: Abundances given in Table 50.2.

Primary reference: B. J. Witzke and M. E. Johnson. 1999. Silurian brachiopod and related benthic communities from carbonate platform and mound environments of Iowa and surrounding areas. In A. J. Boucot and J. D. Lawson (eds.), Paleocommunities--a case study from the Silurian and Lower Devonian 806-840 [M. Foote/M. Foote/M. Foote]more details

Purpose of describing collection: paleoecologic analysis

PaleoDB collection 24966: authorized by Michael Foote, entered by Michael Foote on 23.08.2002

Creative Commons license: CC BY (attribution)

Taxonomic list

Show authors, comments, and common names
unclassified
  -
Streptalasmatidae indet., Conularida indet., Porifera indet.
Porifera indet. Grant 1836
triaxon
Cephalopoda
 Nautiloidea -
Nautiloidea indet.
Nautiloidea indet. Agassiz 1847 nautiloid
orthocone
Gastropoda
  -
Gastropoda indet.
Gastropoda indet. Cuvier 1795 snail
low- and high-spired forms
Bivalvia
 Ostreida - Pterineidae
Pterinea indet.
Pterinea indet. Goldfuss 1832 oyster
Brachiopoda
  -
Brachiopoda indet.
Brachiopoda indet. Cuvier 1805
orthotetacid sp.
Rhynchonellata
 Atrypida - Atrypinidae
"Eospirigerina cf. praemarginalis" = Eospirigerina putilla
"Eospirigerina cf. praemarginalis" = Eospirigerina putilla Hall and Clarke 1894
 Athyridida - Meristellidae
Whitfieldella sp.
Whitfieldella sp. Hall and Clarke 1893
 Orthida -
Orthida indet.
Orthida indet. Schuchert and Cooper 1932
 Orthida - Dalmanellidae
Dalmanella cf. edgewoodensis
 Orthida - Hesperorthidae
? Dolerorthis sp.
? Dolerorthis sp. Schuchert and Cooper 1931
 Orthida - Platystrophiidae
Platystrophia sp.
Strophomenata
 Strophomenida -
Strophomenida indet.
 Strophomenida - Strophonellidae
Strophonella sp.
Strophonella sp. Hall 1879
genus name in quotes
 Strophomenida - Rafinesquinidae
Leptaena sp.
Leptaena sp. Dalman 1828
Stenolaemata
 Trepostomata -
Trepostomata indet.
Trepostomata indet. Ulrich 1882
crustose
 Cryptostomata -
Cryptostomata indet.
Trilobita
  -
Trilobita indet.
Trilobita indet. Walch 1771 trilobite
 Phacopida - Calymenidae
Calymenidae indet., Calymene sp.
Calymenidae indet. Milne-Edwards 1840 trilobite
Calymene sp. Brongniart 1822 trilobite
 Proetida - Proetidae
"Proetus cf. channahonensis" = Hedstroemia channahonensis
"Proetus cf. channahonensis" = Hedstroemia channahonensis Weller 1907 trilobite
 Odontopleurida - Odontopleuridae
Odontopleura sp.
Odontopleura sp. Emmrich 1839 trilobite
Crinoidea
  -
Crinoidea indet.
Crinoidea indet. Miller 1821 Sea lily
Rhombifera
 Rhombifera -
Rhombifera indet.