Union y Progreso (Cretaceous of Mexico)

Where: Coahuila, Mexico (26.8° N, 103.2° W: paleocoordinates 33.3° N, 77.4° W)

• coordinate stated in text

• local area-level geographic resolution

When: Parras Formation, Early/Lower Campanian (83.5 - 70.6 Ma)

• Collected directly from surface exposures where they form part of the desert pavement after they weather out of the Parras Shale. Menabites (Delawarella) vanuxemi (Morton, 1830) represents the upper lower Campanian along the Gulf/Atlantic Coastal plain(s) where it co-occurs with Menabites (Delawarella) delawarensis (Young, 1963; Cobban and Kennedy, 1992b). This latter species is an index fossil for the upper lower Campanian in North America (Kennedy et al., 1992). The subgenus Menabites (Delawarella) is a zonal index for the upper lower Campanian in the Gulf/Atlantic Coastal plains.

• group of beds-level stratigraphic resolution

Environment/lithology: prodelta; lithified shale

• Fine-grained siliciclastics, predominantly shale

Size class: macrofossils

Preservation: mold/impression, replaced with pyrite, replaced with limonite

Collection methods: Repository: Coleccion de Paleontologia de Coahuila (CPC) at the Museo del Desierto, Saltillo, Coahuila, Mexico

Primary reference: C. Ifrim, W. Stinnesbeck, and J. F. Venture. 2013. An endemic cephalopod assemblage from the Lower Campanian (Late Cretaceous) Parras Shale, western Coahuila, Mexico. Journal of Paleontology 87:881-901 [M. Clapham/M. Clapham]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 171307: authorized by Matthew Clapham, entered by Matthew Clapham on 05.07.2015

Creative Commons license: CC BY (attribution)

Taxonomic list

Cephalopoda
 Ammonitida - Muniericeratidae
 Ammonitida - Pachydiscidae
Menuites sp. Spath 1922 ammonite
 Ammonitida - Desmoceratidae
Desmophyllites diphylloides Forbes 1846 ammonite
 Ammonitida - Tetragonitidae
Tetragonites silencioensis n. sp. Ifrim et al. 2013 ammonite
 Ammonitida - Collignoniceratidae
 Ammonitida - Scaphitidae
Scaphites ex gr. hippocrepis DeKay 1828 ammonite
 Ammonitida - Baculitidae
Baculites sp. Lamarck 1799 ammonite
Baculites haresi Reeside 1927 ammonite
 Ammonitida - Nostoceratidae
Nostoceratidae indet. Hyatt 1894 ammonite
 Ammonitida - Diplomoceratidae
Polyptychoceras sp. Yabe 1927 ammonite
 Phylloceratida - Phylloceratidae
Hypophylloceras (Neophylloceras) arturoi n. sp. Ifrim et al. 2013 ammonite
 Nautilida - Nautilidae
Eutrephoceras irritilasi n. sp. Ifrim et al. 2013 nautiloid