Winterswijk Quarry IV shales (Triassic of Netherlands)

Where: Netherlands (52.0° N, 6.8° E: paleocoordinates 38.6° N, 7.3° E)

• coordinate estimated from map

• small collection-level geographic resolution

When: Rhaetian (208.5 - 201.3 Ma)

• The ~4 m of Rhaetian shales at Quarry IV disconcordantly overlie the Anisian strata, and, in turn, are disconcordantly overlain by Oligocene clays.

• group of beds-level stratigraphic resolution

Environment/lithology: paralic; lithified shale

• Deposition of the shales at Winterswijk occurred in a near-coastal, assumedly very shallow, setting. The oligospecific bivalve assemblage and the absence of other benthic groups such as corals, bryozoans and brachiopods (Klompmaker et al. 2010) are indicative of either fluctuating or low salinity levels, dysoxic bottom waters or a combination of both. The presence of a single brittle star species rather than a diverse assemblage as commonly observed in soft-bottom habitats (e.g., Hess 1966) corroborates the assumption of a stressed regime.

Size class: macrofossils

Preservation: replaced with pyrite

Collected in 2006, 2007

• Repository: Naturalis Biodiversity Center (Leiden; NCB-RGM 344 003–344 037) and Freriks Museum, Winterswijk (FMW 0242–21364)

Primary reference: B. Thuy, A. A. Klompmaker, and J. W. M. Jagt. 2012. Late Triassic (Rhaetian) ophiuroides from Winterswijk, the Netherlands; with comments on the systematic position of Aplocoma (Echinodermata, Ophiolepididae). Zoosymposia 7:163-172 [M. Clapham/M. Clapham]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 137660: authorized by Matthew Clapham, entered by Matthew Clapham on 18.12.2012, edited by Thomas Schossleitner

Creative Commons license: CC BY (attribution)

Taxonomic list

Bivalvia indet. Linnaeus 1758 clam
 Ostreida - Pteriidae
Rhaetavicula contorta Portlock 1843 pearl oyster
 Mytilida - Mytilidae
"Modiolus hillanus" = Modiolus (Cyranus) hillanus
"Modiolus hillanus" = Modiolus (Cyranus) hillanus Sowerby 1818 mussel
 Carditida - Carditidae
 Pholadida - Ceratomyidae
Pteromya sp. Moore 1861 clam
 Cardiida - Arcticidae
Isocyprina sp. Röder 1882 clam
 Trigoniida - Myophoriidae
"Lyriomyophoria postera" = Elegantinia
"Lyriomyophoria postera" = Elegantinia clam
 Ophiurida - Ophiolepididae
Aplocoma agassizi von Münster 1839 brittle star