Isorthis orbicularis Horizon of the Basal Leintwardine Fm., Welsh Borderland (Silurian of the United Kingdom)

Where: England, United Kingdom (52.4° N, 2.9° W: paleocoordinates 25.8° S, 12.5° W)

• coordinate based on political unit

• local area-level geographic resolution

When: Lower Leintwardine Formation, Ludfordian (425.6 - 423.0 Ma)

• basal Dayia navicula Beds/Mocktree Shales

• member-level stratigraphic resolution

Environment/lithology: marine; shale

• "Alexander (1936) reported an acme of I. orbicularis in the basal Dayia navicula Beds/Mocktree Shales (Lower Leintwardine Formation) of the Leintwardine region. A thin (10-15 cm) horzon with monospecific and dense assemblages of this brachiopod does occur locally, but with insufficient lateral persistence to warrant separate recognition...I. orbicularis occurs in monospecific assemblages across the shelf region and shows an opportunistic pattern of distribution"

Size class: macrofossils

Primary reference: L. Cherns. 1999. Faunal associations of the Lower Leintwardine Formation of the Anglo-Welsh Basin. In A. J. Boucot and J. D. Lawson (eds.), Paleocommunities--a case study from the Silurian and Lower Devonian 373-379 [M. Foote/M. Foote/M. Foote]more details

Purpose of describing collection: paleoecologic analysis

PaleoDB collection 26301: authorized by Michael Foote, entered by Michael Foote on 11.10.2002

Creative Commons license: CC BY (attribution)

Taxonomic list

Show authors, comments, and common names
Rhynchonellata
 Orthida - Dalmanellidae
Isorthis orbicularis