Saucedas (Cretaceous of Mexico)

Where: Coahuila, Mexico (25.7° N, 101.3° W: paleocoordinates 31.9° N, 75.8° W)

• coordinate stated in text

• outcrop-level geographic resolution

When: Parras Formation, Late/Upper Campanian (83.5 - 70.6 Ma)

• Apparently the Saucedas assemblage, even though collected in a condensed sediment unit of <20 m thickness, covers three to four upper Campanian biozones and thus a long interval of time.

• group of beds-level stratigraphic resolution

Environment/lithology: prodelta; lithified, concretionary, gray, silty shale

• Dark grey silty shale alternating with occasional thin silty-sand layers. The fossils are concentrated in siliceous (carneol?) concretions and silicified lenses.

Size class: macrofossils

Preservation: mold/impression

Collected by C. Ifrim, W. Stinnesbeck in 2008, 2012

Collection methods: surface (float)

• Repository: Colección de Paleontología de Coahuila (CPC) at the Museo del Desierto, Saltillo, Coahuila, Mexico

Primary reference: C. Ifrim, W. Stinnesbeck, B. Espinosa and J. Flores Ventura. 2015. Upper Campanian (Upper Cretaceous) cephalopods from the Parras Shale near Saucedas, Coahuila, Mexico. Journal of South American Earth Sciences 64:229-257 [M. Clapham/M. Clapham/M. Clapham]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 174742: authorized by Matthew Clapham, entered by Matthew Clapham on 26.11.2015, edited by J Fearon

Creative Commons license: CC BY (attribution)

Taxonomic list

Cephalopoda
 Nautilida - Nautilidae
Eutrephoceras irritilasi Ifrim et al. 2013 nautiloid
 Phylloceratida - Phylloceratidae
Phyllopachyceras forbesianum d'Orbigny 1850 ammonite
 Ammonitida - Pachydiscidae
Menuites sp. Spath 1922 ammonite
 Ammonitida - Scaphitidae
Trachyscaphites sp. Cobban and Scott 1964 ammonite
 Ammonitida - Nostoceratidae
Nostoceras hyatti Stephenson 1941 ammonite
Bostrychoceras polyplocum Roemer 1841 ammonite
Exiteloceras jenneyi Whitfield 1877 ammonite
Didymoceras donezianum Michailov 1951 ammonite
 Ammonitida - Baculitidae
Baculites "sp. 2" Lamarck 1799 ammonite
Baculites taylorensis Adkins 1929 ammonite
 Ammonitida - Diplomoceratidae
Diplomoceras cylindraceum Defrance 1816 ammonite
Solenoceras texanum Shumard 1861 ammonite
Solenoceras elegans Kennedy et al. 2000 ammonite
Oxybeloceras crassum Whitfield 1877 ammonite
Malacostraca
 Decapoda - Mathildellidae
Prebranchioplax cretacica Vega and Ahyong 2018 crab