Where: Kemerovo, Russian Federation (54.4° N, 87.5° E: paleocoordinates 49.4° N, 57.7° E)

• coordinate based on nearby landmark

• outcrop-level geographic resolution

When: Maltsevo Formation, Griesbachian (251.9 - 250.5 Ma)

• When the locality was described, it was dated to the Early Triassic; some specialists still believe that it is Early Triassic (Durante and Luvsantseven, 2002; Shcherbakov et al., 2002); Losovsky (1998) believed that the lower beds of the Maltsevo Formation, to which this locality belongs, are Permian, and the upper beds are Triassic; Gomankov and Meyen (1986) considered the entire formation Permian, corresponding to the Vyatkian-Vetlugian gap; this is also what it was considered later by Gomankov (2005). Kukhtinov et al. 2011 place the Maltsevo Formation definitely in the Permian, and dated to the Vyatkian. The composition of the beetle fossils also suggests that this locality belongs to the terminal Permian (Ponomarenko & Volkov, 2013). Davydov et al. (2019) placed the lower Tarakanikha subformation in the Upper Permian but the Kedorovii and Ryaboi Kamen subformations in the Lower Triassic, although Shcherbakov et al. (2020) argued that the Kedrovka subformation was Upper Permian. Radiometric dating by Svetlitskaya & Nevolko (2016) indicated an age of 252.3 +/- 0.6 Ma for the Kedrovka subformation and 251.9 +/- 0.7 Ma for the Ryaboy Kameshek subformation (Ar-Ar ages recalculated from Reichow et al. 2009). Insect fossils are noted at multiple levels in the Tarakanikha, Kedorovii and Ryaboi Kamen subformations by Davydov et al. (2019), and most papers do not specify the precise stratigraphic position. It seems likely that the Maltsevo Formation was deposited during and immediately after the end-Permian extinction, although parts of it could be prior to the biostratigraphically-defined P/T boundary.

• group of beds-level stratigraphic resolution

Environment/lithology: terrestrial; lithified siliciclastic sediments

Size classes: macrofossils, mesofossils

Preservation: mold/impression

Primary reference: D. S. Aristov. 2004. The fauna of grylloblattid insects (Grylloblattida) from the end of the Late Permian to the first half of the Triassic. Paleontological Journal 38:514-521 [M. Clapham/M. Clapham]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 104713: authorized by Matthew Clapham, entered by Matthew Clapham on 08.02.2011, edited by Jered Karr

Creative Commons license: CC BY (attribution)