Calceocrinus pustulosos-Diaphorocrinus Assoc., Rhuddanian, So. Ontario (Silurian of Canada)

Where: Ontario, Canada (43.2° N, 76.8° W: paleocoordinates 24.5° S, 48.0° W)

• coordinate based on political unit

• local area-level geographic resolution

When: Rhuddanian (443.4 - 440.8 Ma)

• "Early Llandoverian (Rhuddanian, A to B1), Cabot Head Shale and Manitoulin Formation."

Environment/lithology: offshore; argillaceous limestone and green shale

• "[Limestones] appear to represent storm-winnowed biostromal layers, and they are surrounded by sparsely fossiliferous green or even reddish shales. Bryozoans evidently grew in local clusters on the outer muddy shelf of the median prodelta...recumbent-stemmed crinoids evidently required local hard subtrates, provided by bryozaon zoaria...The environmental setting is probably analogous to that of the Prolixocrinus Thaerocrinus Comm. of the lsightly later Llandoverian Reynales Limestone...as evidence by a similar brachiopod and bryozoan fauna and presence of calceocrinoids as accessory faunal elements. As in the latter case the Cabot Head calceocrinid occurrences are interpreted as outer shoal marginal environments belonging to BA 3 to inner BA 4."

•SEP: this is tough to assign to rigid carbonate/clastic settings. I have put it clastic setting because it is dominated by shales and is in the "clastic wedge" of the Silurian of the App. foreland basin

• "Bryozoan-rich lenses of argillaceous limestone...sourrounded by sparsely fossiliferous green or even reddish shales..."

Primary reference: T. J. Frest, C. E. Brett, and B. J. Witzke. 1999. Caradocian-Gedinnian echinoderm associations of Central and Eastern North America. Paleocommunities--a case study from the Silurian and Lower Devonian 638-783 [M. Foote/K. Koverman/P. Wagner]more details

Purpose of describing collection: paleoecologic analysis

PaleoDB collection 26776: authorized by Michael Foote, entered by Michael Foote on 31.10.2002

Creative Commons license: CC BY (attribution)

Taxonomic list

Show authors, comments, and common names
Crinoidea
 Calceocrinida - Calceocrinidae
Diaphorocrinus pleniramulatus, Calceocrinus pustulosus
Strophomenata
 Orthotetida - Chilidiopsidae
"Coolinia sp." = Fardenia (Coolinia)
"Coolinia sp." = Fardenia (Coolinia) Bancroft 1949
Rhynchonellata
 Orthida - Dalmanellidae
Resserella sp.
Resserella sp. Bancroft 1928
 Orthida - Platystrophiidae
Platystrophia sp.
Bryozoa
  -
Bryozoa indet.
Bryozoa indet. Ehrenberg 1831
ramose (twig-like)
Stenolaemata
 Cryptostomata - Arthrostylidae
Helopora sp.
Helopora sp. Hall 1851
 Cryptostomata - Ptilodictyidae
Phaenopora sp.
Phaenopora sp. Hall 1851
Bivalvia
 Autobranchia -
Pterioida indet.
Pterioida indet. Newell 1965 clam
Trilobita
 Phacopida - Calymenidae
Liocalymene sp.
Liocalymene sp. Raymond 1916 trilobite