Where: Sonora, Mexico (30.2° N, 111.7° W: paleocoordinates 15.9° N, 50.7° W)

• coordinate stated in text

• local area-level geographic resolution

When: Freboldi ammonoid zone, Middle Member (Sierra de Santa Rosa Formation), Early/Lower Pliensbachian (189.6 - 183.0 Ma)

Environment/lithology: deep-water; lithified, calcareous mudstone and lithified, gray, blue limestone

Size class: macrofossils

Preservation: cast, mold/impression

Collection methods: surface (in situ)

• Estación Regional del Noroeste, Instituto de Geología,

•Universidad Nacional Autónoma de México in Hermosillo, with collection numbers with the prefix ERNO

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 208274: authorized by József Pálfy, entered by Dorina Juhász on 26.03.2020

Creative Commons license: CC BY (attribution)