Cobourg Hill (S6) No 1, west railway-cut, lot 15, Lake Simcoe area (Ordovician of Canada)

Where: Ontario, Canada (44.5° N, 79.0° W: paleocoordinates 24.9° S, 55.0° W)

• coordinate estimated from map

• outcrop-level geographic resolution

When: Climacograptus spiniferus graptolite zone, Upper Member (Verulam Formation), Chatfieldian (460.9 - 449.5 Ma)

• C1

• 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 26277: authorized by Steven Holland, entered by Tori Hanson on 10.10.2002, edited by Pete Wagner

Creative Commons license: CC BY (attribution)

Taxonomic list

 Corynexochida - Illaenidae
 Phacopida - Pterygometopidae
Achatella achates Billings 1860 trilobite
 Phacopida - Calymenidae
Flexicalymene senaria Conrad 1841 trilobite
 Billingsellida - Clitambonitidae
Vellamo trentonensis Raymond 1921
 Strophomenida - Sowerbyellidae
"Sowerbyella sericea" = Sowerbyella (Sowerbyella) sericea Sowerby 1839
 Strophomenida - Rafinesquinidae
Rafinesquina alternata Conrad 1838
R. alternata alata and R. alternata intermedia and R. alternata plana and R. alternata platys
 Strophomenida - Strophomenidae
Opikina cf. septata Salmon 1942
O. cf. septata borealis
Opikina platys Wilson 1944
Opikina rugosa Wilson 1921
O. rugosa and O. rugosa avita
 Pentamerida - Parastrophinidae
 Atrypida - Anazygidae
"Zygospira recurvirostris" = Anazyga recurvirostra
"Zygospira recurvirostris" = Anazyga recurvirostra Hall 1847
 Rhynchonellida - Rhynchotrematidae
 Orthida - Dalmanellidae
 Orthida - Plaesiomyidae
"Dinorthis cf. iphigenia" = Plaesiomys iphigenia Billings 1865
D. cf. iphigenia and D. iphigenia media
Dinorthis pectinella Emmons 1842
D. pectinella and D. pectinella sweeneyi
 Orthida - Platystrophiidae
 Cyrtodontida - Cyrtodontidae
"Whitella compressa" = Cyrtodontula compressa Ulrich 1890 clam
 Myalinida - Ambonychiidae
"Ambonychia amygdalina" = Ambonychinia amygdalina
"Ambonychia amygdalina" = Ambonychinia amygdalina Hall 1847 clam
 Mytilida - Modiolopsidae
Paramodiola sp. Isberg 1934 clam
 Cardiidia - Grammysiidae
Cuneamya sp. Hall and Whitfield 1875 clam
 Megalodontida - Plethocardiidae
Plethocardia suberecta Ulrich 1894 clam
 Modiomorphida - Modiomorphidae
Saffordia cf. ventralis Ulrich 1894 clam
 Protobranchia - Ctenodontidae
Ctenodonta nasuta Hall 1847 clam
Ctenodonta cf. logani Salter 1859 clam
Ctenodonta cf. madisonensis Ulrich 1894 clam
 Protobranchia -
"Cleidophorus sp." = Nuculites
"Cleidophorus sp." = Nuculites Conrad 1841 clam
 Trochonematoidea - Trochonematidae
Trochonema fragile Ulrich and Scofield 1897 snail
"Trochonema umbilicatum" = Trochonema umbilicata Hall 1847 snail
Trochonema vagrans Ulrich and Scofield 1897 snail
 Trochonematoidea - Lophospiridae
Lophospira perangulata Hall 1847 snail
"Lophospira saffordi" = Paupospira oweni Ulrich and Scofield 1897 snail
 Euomphalina - Euomphalidae
"Helicotoma spinosa" = Linsleyella spinosa
"Helicotoma spinosa" = Linsleyella spinosa Salter 1859 snail
 Euomphalina - Platyceratidae
Cyclonema gracile Ulrich and Scofield 1897 snail
 Bellerophontida - Sinuitidae
"Sinuites cancellatus" = Sinuites cancellatus, "Sinuites corrugatus" = Sinuites cancellatus
"Sinuites cancellatus" = Sinuites cancellatus Hall 1847 snail
S. cancellatus and S. cancellatus angularis
"Sinuites corrugatus" = Sinuites cancellatus Hall 1847 snail
S. bilobatus corrugatus
 Bellerophontida - Temnodiscidae
"? Tropidodiscus disculus" = Alaskadiscus disculus
"? Tropidodiscus disculus" = Alaskadiscus disculus Billings 1860 snail
 Bellerophontida - Bucaniidae
Bucania halli Ulrich and Scofield 1897 snail
 Murchisoniina - Eotomariidae
Liospira progne Billings 1860 snail
Liospira micula Hall and Whitney 1862 snail
Eotomaria sp. Ulrich and Scofield 1897 snail
 Murchisoniina - Murchisoniidae
"Hormotoma salteri" = Cyrtostropha salteri
"Hormotoma salteri" = Cyrtostropha salteri Ulrich and Scofield 1897 snail
H. salteri canadensis
 Murchisoniina - Hormotomidae
Hormotoma gracilis Hall 1847 snail
Hormotoma simplex Wilson 1932 snail
H. simplex and H. simplex paquettensis
 Murchisoniina - Loxonematidae
"Hormotoma trentonensis" = Omospira trentonensis
"Hormotoma trentonensis" = Omospira trentonensis Ulrich and Scofield 1897 snail
 Cryptostomata - Rhinidictyidae
 Trepostomata - Heterotrypidae
 Glyptocystitoida - Pleurocystitidae
 Camerata - Reteocrinidae
Reteocrinus sp. Billings 1859 Sea lily
 Stauriida - Streptelasmatidae
Streptelasma corniculum Hall 1847 horn coral
 Conulariida - Conulariidae