Where: Sonora, Mexico (30.6° N, 112.6° W: paleocoordinates 18.3° N, 55.1° W)

• coordinate estimated from map

• local area-level geographic resolution

When: Leslei ammonoid zone, Lower Jurassic upper Member (Sierra de Santa Rosa Formation), Early/Lower Sinemurian (196.5 - 189.6 Ma)

• Sequence XI, informal unit 18

Environment/lithology: deep-water; lithified, argillaceous mudstone and lithified siltstone

Size class: macrofossils

Preservation: cast, mold/impression

Collection methods: surface (in situ)

• Estación Regional del Noroeste (ERNO), Instituto de Geología,Universidad Nacional Autónoma de México collection

Primary reference: D. Szűcs, C. M. González-León, and J. Pálfy. 2019. Ammonoid biostratigraphy and paleobiogeography of Lower Jurassic sections from Sonora (northwest Mexico) and their tectonic implications. Journal of South American Earth Sciences 93:267-282 [J. Pálfy/D. Juhász/P. Wagner]more details

Purpose of describing collection: biostratigraphic analysis

PaleoDB collection 208243: authorized by József Pálfy, entered by Dorina Juhász on 25.03.2020

Creative Commons license: CC BY (attribution)