Facies of two important Early Triassic gastropod lagerstätten: implications for diversity patterns in the aftermath of the end-Permian mass extinction

Journal article


Publication Details

Author(s): Nützel A, Schulbert C
Journal: Facies
Publisher: Springer Verlag (Germany)
Publication year: 2005
Volume: 51
Pages range: 480-500
ISSN: 0172-9179


Abstract


Two important lagerstätten of Early Triassic gastropods, the Sinbad Limestone (Utah, USA) and the Gastropod Oolite (North Italy) yield about 40% of all described Early Triassic species. This great contribution to the global diversity and the exceptional good preservation render high information content, which characterizes fossil lagerstätten. The Smithian Sinbad Limestone contains the most diverse Early Triassic gastropod fauna. At the type locality, it occurs in single, probably storm-induced shell bed within a series of high energy deposits underlain by intertidal microbial mats and subtidal oolite/peloid shoals. The main shell bed contains about 40 invertebrate taxa. Gastropods, scaphopods, and bivalves are most abundant and form an assemblage, which is dominated by small neritaemorphs, the opisthobranch Cylindrobullina convexa and the scaphopod Plagioglypta (annulated tubes). This assemblage lived on shallow, subtidal soft-bottoms based on sedimentological and ecological characteristics. The Dienerian (to Smithian?) Gastropod Oolite Member (North Italy) has extremely abundant, probably salinity-controlled gastropod faunas with low species richness. Almost monospecific assemblages of Pseudomurchisonia kokeni as well as assemblages with about four species are present in the Gastropod Oolite. Modern hydrobiid mudsnail faunas which are adapted to strongly fluctuating salinity in intertidal to shallow subtidal coastal areas form probably a suitable model for the Gastropod Oolite biota. Gastropods from the Werfen- and Moenkopi-Formation lagerstätten are well preserved compared to other Early Triassic deposits. The high contribution to the global diversity of just two sites suggests very incomplete sampling and preservational bias. However, the low richness of the major faunas reflects depauperate Early Triassic faunas and slow recovery from the Permian/Triassic crisis. © Springer-Verlag 2005.



FAU Authors / FAU Editors

Schulbert, Christian
Lehrstuhl für Paläoumwelt


How to cite

APA:
Nützel, A., & Schulbert, C. (2005). Facies of two important Early Triassic gastropod lagerstätten: implications for diversity patterns in the aftermath of the end-Permian mass extinction. Facies, 51, 480-500. https://dx.doi.org/10.1007/s10347-005-0074-5

MLA:
Nützel, Alexander, and Christian Schulbert. "Facies of two important Early Triassic gastropod lagerstätten: implications for diversity patterns in the aftermath of the end-Permian mass extinction." Facies 51 (2005): 480-500.

BibTeX: 

Last updated on 2018-21-07 at 08:23