| Becscie Formation | |
|---|---|
| Stratigraphic range: | |
| Type | Geological formation |
| Sub-units |
|
| Underlies | Gun River Formation |
| Overlies | Ellis Bay Formation |
| Thickness | 80 to 85 meters |
| Location | |
| Region |  Quebec |
| Country |  Canada |
The Becscie Formation is a geologic formation in Quebec. It preserves fossils dating back to the early Silurian period.
The Becscie Formation is 80 to 85 meters thick. [1] It overlies the Ordovician-Silurian boundary on Anticosti Island, marking a major oceanic and climatic changeover from the glacial sea-level lowstand and interglacial highstand cycles of the underlying Ellis Bay Formation to the more stable warming climate of the earliest Silurian, and extends approximately parallel to an ancient coastline some 200 km east to west. [1] The formation is divided into two members, a lower Fox Point Member (spanning the Viridita lenticularis Biozone), and an upper Chabot Member (spanning the Virgiana barrandei Biozone). [1]
| Arthropods | |||||
|---|---|---|---|---|---|
| Genus | Species | Presence | Material | Notes | Images |
| Anticostibolbina | Chabot Member. [1] | A beyrichiacean ostracod. | |||
| Bolbineossia | Chabot Member. [1] | A beyrichiacean ostracod. | |||
| Conbathella | Chabot Member. [1] | A beyrichiacean ostracod. | |||
| Herrmannina | H. selwyni | Lower Becscie Formation. [1] | An ostracod | ||
| Zygobursa | Chabot Member. [1] | A beyrichiacean ostracod. | |||
| Brachiopods | |||||
|---|---|---|---|---|---|
| Genus | Species | Presence | Material | Notes | Images |
| Becscia | B. scissura | "Occurs commonly in lenses and clusters". [1] | An atrypid. [1] | ||
| Biparetis | Elsewhere known from the early Silurian, but locally rare. [1] | ||||
| Brachyprion | Occurs sparsely in the Chabot Member. [1] | ||||
| Eospirigerina | E. sp. | Fox Point Member. [1] | An unnamed species, represents earliest known Silurian species of this Ordovician genus. | ||
| Hesperorthis | Fox Point Member. [1] | An orthide. [1] | |||
| Isorthis (Ovalella) | Fox Point Member. [1] | An orthide. [1] | |||
| Koigia | An athyridid, originally reported as Hindella. [1] | ||||
| Leptaena | Fox Point Member bedding plane. [1] | ||||
| Mendacella | M. udauberis | Fox Point Member, rare in the Chabot Member. [1] | An orthide. [1] | ||
| Saukrodictya | Fox Point Member. [1] | An orthide. [1] | |||
| Virgiana | V. barrandei | Only in the Chabot Member. [1] [2] | A large-shelled pentameride. [1] | ||
| Viridita | V. becsciensis | Fox Point Member. [2] | "Holotype, YPM 10341, and paratype, YPM 35519". [2] | ||
| V. lenticularis | Near the top of the Fox Point Member, [1] and the Chabot Member. [2] | ||||
| Zygospiraella | Z. cf. Z. planoconvexa | Lower Becscie Formation, rare taxon in the lower Chabot Member. [1] | |||
| Bryozoans | |||||
|---|---|---|---|---|---|
| Genus | Species | Presence | Material | Notes | Images |
| Phaenopora | P. superba | Fox Point and Chabot Members. [1] | "Extends into the overlying Gun River Formation" [3] | ||
| Corals | |||||
|---|---|---|---|---|---|
| Genus | Species | Presence | Material | Notes | Images |
| Acidolites | A. arctatus | [4] | A heliolitid. | ||
| A. compactus | [4] | A heliolitid. | |||
| A. lindströmi | [4] | A heliolitid. | |||
| Nanonphyllum | N. pelagicum | Common in the Chabot Member. [1] | A colonial rugose coral. | ||
| Paleofavosites | More common towards the upper part of the Fox Point Member. [1] | A heliolitid tabulate coral. [1] | |||
| Palaeophyllum | Common in the Chabot Member. [1] | ||||
| Propora | More common towards the upper part of the Fox Point Member. [1] | A heliolitid tabulate coral. [1] | |||
| Crinoids | |||||
|---|---|---|---|---|---|
| Genus | Species | Presence | Material | Notes | Images |
| Alopocrinus | Fox Point and Chabot members. [1] | ||||
| Becsciecrinus | Fox Point and Chabot members. [1] | ||||
| Dendrocrinus | Chabot Member. [1] | ||||
| Eumyelodactylus | Fox Point Member. [1] | ||||
| Euspirocrinus | Fox Point Member. [1] | ||||
| Protaxocrinus | Fox Point Member. [1] | ||||
| Xenocrinus | Chabot Member. [1] | ||||
| Gastropods | |||||
|---|---|---|---|---|---|
| Genus | Species | Presence | Material | Notes | Images |
| Hormotoma | Eastern side of Anticosti Island. [1] | A hormotomid. | |||
| Subulites | Eastern side of Anticosti Island. [1] | A soleniscid. | |||
| Graptolites | |||||
|---|---|---|---|---|---|
| Genus | Species | Presence | Material | Notes | Images |
| Climacograptus | C. typicalis var. atlanticus | [5] | |||
| Sponges | |||||
|---|---|---|---|---|---|
| Genus | Species | Presence | Material | Notes | Images |
| Clathrodictyon | C. boreale | Fox Point and Chabot members. [1] | "A single small, spheroidal specimen". [1] | A stromatoporoid. [1] | |
| Ecclimadictyon | E. macrotuberculatum | Chabot Member. [1] | A stromatoporoid. | ||
| Pachystylostroma | Very top of the Chabot Member. [1] | A stromatoporoid. | |||
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Aulacopleura is a genus of proetid trilobite that lived from the Middle Ordovician to the Middle Devonian. Some authors may classify this group as subgenus Otarion (Aulacopleura). The cephalon is semicircular or semielliptical, with border and preglabellar field. The glabella is short, with or without defined eye ridges connecting it with eyes of variable size. Spines at the rear outer corners of the cephalon are present, typically reaching back to the 2nd to 4th thorax segment. The 'palate' is not connected to the dorsal shield of the cephalon. The cephalon is pitted, or has small tubercles. The thorax has up to 22 segments. The pleural ends are usually rounded. The pygidium is small (micropygous), with an even margin. A. koninckii had a modern type of compound eye.
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The Georgian Bay Formation is a geologic formation in Michigan and Ontario. It preserves fossils dating back to the Ordovician period. The type locality of the formation is on East Meaford Creek, south shore of Nottawasaga Bay, Georgian Bay.
The Lueders Formation is a geologic formation in Texas. It is the top formation of the Albany Group and preserves fossils dating back to the Permian period.
The Johnson Spring Formation is a geologic formation in California. It preserves fossils dating back to the Ordovician period.
The Attawapiskat Formation is a geologic formation in Ontario. It preserves fossils dating back to the Silurian period.
The Merrimack Formation is a geologic formation in Quebec. It preserves fossils dating back to the Silurian period.
The Gun River Formation is a geologic formation in Quebec. It preserves fossils dating back to the early Silurian period.
The Jupiter Formation is a geologic formation in Quebec, well-exposed in the southern third of Anticosti Island and lying in the St Lawrence River Valley. It preserves fossils dating back to the Silurian period.
The Campbellton Formation is a geologic formation in New Brunswick. It preserves fossils dating back to the latest Pragian and Emsian of the Devonian period.
The Cowie Formation is geological formation located on the Highland Boundary Fault between the fishing village of Cowie and Ruthery Head, in Aberdeenshire, Scotland. Age of this formation is controversial, that was originally estimated at the Middle Silurian, Wenlock to Ludlow, but zircon geochronology shows the Early Devonian, Lochkovian instead. In study published in 2023, according to spore microfossils and additional zircon data, the Middle Silurian, late Wenlock age is suggested again. This formation preserves fossils, including a millipedes such as Pneumodesmus and Cowiedesmus that were discovered by Mike Newman in 2001, and some agnathan like Cowielepis.
The Solvik Formation is a geologic formation in the central Oslo Region of Norway. It preserves fossils dating back to the early Silurian period.
Anticostiodus is an extinct genus of multielement conodonts. Specimens have been described from the Lower Silurian of Gun River Formation of Anticosti Island, Quebec. Two species are included under the genus, Anticostiodus fahraeusi and Anticostiodus boltoni. Both species occur near the base of the Distomodus staurognathoides zone and in an open subtidal environment.
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