Zion South (S7) section, lot 10, Lake Simcoe area (Ordovician of Canada)

Where: Ontario, Canada (44.4° N, 78.8° W: paleocoordinates 25.1° S, 54.9° W)

• coordinate estimated from map

• outcrop-level geographic resolution

When: upper Member (Verulam Formation), Caradoc (458.4 - 449.5 Ma)

• member-level stratigraphic resolution

Environment/lithology: deep subtidal; gray limestone and argillaceous limestone

• "[B]rownish grey and grey, fine- to coarse-crystalline, bioclastic, crinoidal limestone in beds an inch to 3 inches thick, together with minor amounts of argillaceous limestone and granular fragmental limestone. The strata locally weather grey and brown into beds 8 to 10 inches thick. A peculiar weathering phenomenon, involving a thin, regular, discoidal sheeting effect, oblique to individual beds, and cutting across them, is characteristic and is considered to be crossbedding. On the uppermost surface and visible at only two localities within the map-area, are large ripple-like structures, as much as 30 inches in wave length and 6 inches in amplitude. They are considered to be para-ripples modified by glacial scour action."

Size class: macrofossils

Primary reference: B. A. Liberty. 1969. Palaeozoic geology of the Lake Simcoe Area, Ontario. Geological Survey of Canada Memoirs (355)1-201 [S. Holland/T. Hanson/T. Hanson]more details

Purpose of describing collection: biostratigraphic analysis

PaleoDB collection 26274: authorized by Steven Holland, entered by Tori Hanson on 10.10.2002, edited by Pete Wagner

Creative Commons license: CC BY (attribution)

Taxonomic list

Show authors, comments, and common names
Gastropoda
 Murchisoniina - Murchisoniidae
"Hormotoma salteri" = Cyrtostropha salteri
"Hormotoma salteri" = Cyrtostropha salteri Ulrich and Scofield 1897 snail
H. salteri canadensis
 Bellerophontida - Sinuitidae
Sinuites cancellatus
Sinuites cancellatus Hall 1847 snail
 Bellerophontida - Bucaniidae
"Salpingostoma cf. expansum" = Salpingostoma expansa, Bucania halli
"Salpingostoma cf. expansum" = Salpingostoma expansa Hall 1847 snail
Bucania halli Ulrich and Scofield 1897 snail
 Euomphalina - Helicotomidae
Helicotoma sp.
Helicotoma sp. Salter 1859 snail
Bivalvia
 Solemyida - Ctenodontidae
Ctenodonta nasuta
Ctenodonta nasuta Hall 1847 clam
Strophomenata
 Strophomenida - Sowerbyellidae
"Sowerbyella sericea" = Sowerbyella (Sowerbyella) sericea
"Sowerbyella sericea" = Sowerbyella (Sowerbyella) sericea Sowerby 1839
 Strophomenida - Strophomenidae
Opikina cf. rugosa, Opikina platys
Opikina cf. rugosa Wilson 1921
Opikina platys Wilson 1944
 Strophomenida - Rafinesquinidae
Rafinesquina trentonensis, "Rafinesquina alata" = Rafinesquina alternata alata
"Rafinesquina alata" = Rafinesquina alternata alata Wilson 1944
R. alternata alata and R. alternata intermedia
Rhynchonellata
 Orthida - Dalmanellidae
Paucicrura rogata
Paucicrura rogata Sardeson 1892
 Atrypida - Anazygidae
"Zygospira recurvirostris" = Anazyga recurvirostra
"Zygospira recurvirostris" = Anazyga recurvirostra Hall 1847
 Rhynchonellida - Rhynchotrematidae
Rhynchotrema increbescens
Stenolaemata
 Cryptostomata - Rhinidictyidae
Rhinidictya mutabilis
 Cryptostomata - Ptilodictyidae
Stictoporella sp.
Stictoporella sp. Ulrich 1882
 Trepostomida - Monticuliporidae
Prasopora simulatrix, Prasoporina selwyni
Prasopora simulatrix
P. simulatrix orientalis
 Trepostomata - Heterotrypidae
Dekayella cf. trentonensis
Trilobita
 Asaphida - Asaphidae
Isotelus cf. maximus, Isotelus gigas
Isotelus cf. maximus Locke 1838 trilobite
Isotelus gigas Dekay 1824 trilobite
 Phacopida - Pterygometopidae
Achatella cf. billingsi