Breadstone trench (Ordovician of the United Kingdom)

Where: United Kingdom (51.7° N, 2.4° W: paleocoordinates 74.6° S, 19.4° W)

• coordinate estimated from map

• outcrop-level geographic resolution

When: Breadstone Shales Formation, Tremadocian (485.4 - 477.7 Ma)

• group of beds-level stratigraphic resolution

Environment/lithology: offshore shelf; lithified, micaceous, gray, blue shale and lithified, fine-grained sandstone

• offshore deposits formed in rather shallow waters, quiet conditions of deposition
• Uniform series of soft, thinly bedded, micaceous shales, usually grey, bluish-grey or greenish-grey, but weathering to yellowish-grey, buff or rusty colour. Hard bands of finegrained sandstone, generally less than a quarter of an inch in thickness but locally as much as two or three inches, occur interbedded with the shales. These sandstone bands are not constant in thickness and commonly wedge out laterally.

Size classes: macrofossils, mesofossils

Preservation: mold/impression

Collected by M. L. K. Curtis in 1971

Primary reference: M. L. K. Curtis. 1968. The Tremadoc rocks of the Tortworth Inlier, Gloucestershire. Proceedings of the Geologists' Association 79(3):349-362 [M. Hopkins/M. Hopkins]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 208223: authorized by Melanie Hopkins, entered by Melanie Hopkins on 24.03.2020

Creative Commons license: CC BY (attribution)

Taxonomic list

Show authors, comments, and common names
Pterobranchia
 Graptoloidea - Anisograptidae
"Dictyonema flabelliforme" = Rhabdinopora flabelliformis
"Dictyonema flabelliforme" = Rhabdinopora flabelliformis Eichwald 1840 graptolite
Lingulata
 Lingulida - Obolidae
Lingulella nicholsoni, Lingulella sp.
Lingulella sp. Salter 1866
Gastropoda
 Bellerophontida - Bellerophontidae
Bellerophon sp.
Bellerophon sp. de Montfort 1808 snail
Ostracoda
  -
Septadella jackmanae
Septadella jackmanae Smith and Stubblefield 1933 ostracod
Trilobita
 Asaphida - Asaphidae
"Niobella (Niobe) homfrayi" = Niobe (Niobella) homfrayi
"Niobella (Niobe) homfrayi" = Niobe (Niobella) homfrayi Salter 1866 trilobite
Niobella (Niobe) homfrayi smithi
 Olenida - Olenidae
"Beltella depressa" = Leptoplastides depressus
"Beltella depressa" = Leptoplastides depressus Salter In Murchinson 1859 trilobite
Artiopoda
 Agnostida - Agnostidae
"Agnostus calvus" = Micragnostus calvus
"Agnostus calvus" = Micragnostus calvus Lake 1906