The Becscie Formation is a geologic formation in Quebec. It preserves fossils dating back to the early Silurian period.
Description The Becscie Formation is 80 to 85 meters thick. 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. 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).
Fossil content Arthropods Genus Species Presence Material Notes ImagesAnticostibolbinaChabot Member.A beyrichiacean ostracod.BolbineossiaChabot Member.A beyrichiacean ostracod.ConbathellaChabot Member.A beyrichiacean ostracod. HerrmanninaH. selwyni Lower Becscie Formation. An ostracodZygobursaChabot Member.A beyrichiacean ostracod.
Brachiopods Genus Species Presence Material Notes ImagesBecsciaB. scissura"Occurs commonly in lenses and clusters".An atrypid.BiparetisElsewhere known from the early Silurian, but locally rare.BrachyprionOccurs sparsely in the Chabot Member.EospirigerinaE. sp.Fox Point Member.An unnamed species, represents earliest known Silurian species of this Ordovician genus.HesperorthisFox Point Member.An orthide.Isorthis (Ovalella)Fox Point Member.An orthide.KoigiaAn athyridid, originally reported as Hindella.LeptaenaFox Point Member bedding plane.MendacellaM. udauberisFox Point Member, rare in the Chabot Member.An orthide.SaukrodictyaFox Point Member.An orthide.VirgianaV. barrandeiOnly in the Chabot Member.A large-shelled pentameride.ViriditaV. becsciensisFox Point Member."Holotype, YPM 10341, and paratype, YPM 35519".V. lenticularis Near the top of the Fox Point Member, and the Chabot Member.ZygospiraellaZ. cf. Z. planoconvexaLower Becscie Formation, rare taxon in the lower Chabot Member.
Bryozoans Genus Species Presence Material Notes Images PhaenoporaP. superba Fox Point and Chabot Members. "Extends into the overlying Gun River Formation"
Corals Genus Species Presence Material Notes ImagesAcidolitesA. arctatusA heliolitid.A. compactusA heliolitid.A. lindströmiA heliolitid.NanonphyllumN. pelagicumCommon in the Chabot Member.A colonial rugose coral.PaleofavositesMore common towards the upper part of the Fox Point Member.A heliolitid tabulate coral.PalaeophyllumCommon in the Chabot Member. Propora More common towards the upper part of the Fox Point Member. A heliolitid tabulate coral.
Crinoids Genus Species Presence Material Notes ImagesAlopocrinusFox Point and Chabot members.BecsciecrinusFox Point and Chabot members.DendrocrinusChabot Member. Eumyelodactylus Fox Point Member.EuspirocrinusFox Point Member.ProtaxocrinusFox Point Member.XenocrinusChabot Member.
Gastropods Genus Species Presence Material Notes Images Hormotoma Eastern side of Anticosti Island. A hormotomid. SubulitesEastern side of Anticosti Island.A soleniscid.
Graptolites Genus Species Presence Material Notes Images ClimacograptusC. typicalis var. atlanticus
Sponges Genus Species Presence Material Notes Images ClathrodictyonC. boreale Fox Point and Chabot members."A single small, spheroidal specimen". A stromatoporoid. EcclimadictyonE. macrotuberculatumChabot Member.A stromatoporoid.PachystylostromaVery top of the Chabot Member.A stromatoporoid.
See also
List of fossiliferous stratigraphic units in Quebec
References