Where: Singapore (1.3° N, 103.8° E: paleocoordinates 12.4° N, 107.5° E)

• coordinate based on nearby landmark

• outcrop-level geographic resolution

When: Jurong Formation, Late/Upper Triassic to Late/Upper Triassic (237.0 - 174.7 Ma)

• "Permian, possibly Artinskian" according to Morris et al., based on redescription of "Goniomya" singaporensis, which he thought belonged to the Permian genus Undulomya (with similarity to the Early Permian Undulomya pleiopleura). Could be younger because Undulomya pleiopleura (a synonymous species) ranges from Kungurian-Roadian in Western Australia. 2-foot (circa) bed of silty clay.

•Wanner (1931) considered these beds to be Upper Triassic, perhaps equivalent to those found at Mount Faber.

•Fossil evidence, reviewed by Kobayashi and Tamura (1968a) and summarised in Gobett and Hutchison (1973), places the shallow water marine argillaceous units (Ayer Chawan Facies) in the Carnian or Norian i.e. in the Late Triassic between 237.0 and 209.5 Ma (these and other ages for various epochs and stages are quoted from Gradstein et al., 2012). Newton (1906) described marine bivalves from Mt Guthrie, Singapore, that according to Jones et al. (1966) are quite different from any Triassic fossils from Peninsular Malaysia and which Kobayashi and Tamura (1968b) suggested were probably Lower Jurassic. However, Lower to Middle Jurassic fossils have not been found in Peninsular Malaysia (Nuraiteng, 2009) or southwest Thailand (Booth and Sattayarak, 2011) and the existence of Lower Jurassic strata in Singapore is doubtful.

• group of beds-level stratigraphic resolution

Environment/lithology: marine; lithified, silty mudstone

Size class: macrofossils

Preservation: mold/impression

Collected by John B. Scrivenor

Primary reference: R. B. Newton. 1906. Notice of some fossils from Singapore discovered by John B. Scrivenor, FGS, geologist to the Federated Malay States. The Geological Magazine, New Series, Decade V 3:487-496 [M. Clapham/M. Clapham/M. Clapham]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 113863: authorized by Matthew Clapham, entered by Matthew Clapham on 06.08.2011

Creative Commons license: CC BY (attribution)