Pennsylvanian Bryozoans of Exceptional Preservation from the Buckhorn Asphalt Quarry, Oklahoma

Seuß B, Taylor P, Ernst A, Nützel A (2016)

Publication Language: English

Publication Type: Conference contribution, Abstract of a poster

Publication year: 2016

Event location: Denver US

Abstract

The Pennsylvanian (Desmoinesian–Virgilian) Buckhorn Asphalt Quarry (Boggy Formation, Deese Group) in Oklahoma, USA is well known for its exceptional preservation of a diverse marine invertebrate fauna. This includes preservation of original shell material, microscopic characters on shells, or color patterns. Preservation is exceptionally because of early impregnation with hydrocarbons that soaked sediments and fossils. Results from the latest study and the first focusing exclusively on the Buckhorn bryozoans are presented. Nine genera and species are recognized, two of them are new (Stenophragmidium buckhornensis and Streblotrypa (S.) heltzelae) and two genera (Shishoviclema, Shulgapora) are identified in North American strata for the first time. Some skeletal characteristics that are usually lost during diagenesis are uniquely preserved or seen for the first time in Paleozoic bryozoans. These include small to large (5-50 µm in diameter) node-like surface expressions of styles that most likely strengthened the skeleton or were for attachment of the soft tissue rather than defense. ‘Nanoperforations’ observed in S. (S.) heltzelae, S. buckhornensis and Rhombocladia delicatula are tiny holes with a diameter of only 0.5 µm countersunk (bevelled) into the laminated skeletal walls. Such structures are unknown from other bryozoans (recent and fossil) and their genesis – produced by small-sized symbionts (bacteria?), by microendoliths or by the bryozoans themselves? – is unclear. The most likely hypothesis is that they are due to symbionts that lived embedded in the growing walls of the bryozoan zooids. In fractured branches of S. (S.) heltzelae, closely spaced ‘granule’ bands (diameter of granules approximately 6 µm) on the walls of the autozooids were found. Again, such structures have not been observed elsewhere and their origin and function are enigmatic. Mural spines (of varied size and morphology depending on the genus) are reported from R. delicata and Stenoporella sp. Spinose hemiphragms, with spines of 3-30 µm in length, are new features of unknown function found in some trepostomes. Finally, a transverse fibrous fabric found in the fenestrate Septopora blanda is reminiscent of a fabric common in post-Paleozoic cyclostome bryozoans but hitherto not reported in palaeostomates from the Paleozoic.

Authors with CRIS profile

Barbara Seuß Lehrstuhl für Paläoumwelt

Related research project(s)

Paleobiodiversity and community structures of Lagerstätten during the Late Paleozoic Ice Age and the response of the marine benthic invertebrate fauna to global cooling July 1, 2014 - July 1, 2017

Involved external institutions

Ludwig-Maximilians-Universität (LMU) DE Germany (DE) Universität Hamburg (UHH) DE Germany (DE)

How to cite

APA:

Seuß, B., Taylor, P., Ernst, A., & Nützel, A. (2016). Pennsylvanian Bryozoans of Exceptional Preservation from the Buckhorn Asphalt Quarry, Oklahoma. Poster presentation at GSA Annual Meeting, Denver, US.

MLA:

Seuß, Barbara, et al. "Pennsylvanian Bryozoans of Exceptional Preservation from the Buckhorn Asphalt Quarry, Oklahoma." Presented at GSA Annual Meeting, Denver 2016.

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