Four Corners Section - 7A (Cretaceous of the United States)

Where: San Juan County, New Mexico (36.8° N, 108.9° W: paleocoordinates 37.7° N, 71.9° W)

• coordinate stated in text

When: Mancos Formation, Late/Upper Cenomanian (99.6 - 93.5 Ma)

• time equivilant [to the Upper Cenomanian Hartland Shale Member, Greenhorn Formation] proximal offshore deposits (prodelta and equivalents; Danke et al., 1993) of the Tropic and Mancos Shales

• bed-level stratigraphic resolution

Environment/lithology: prodelta; lithified, bioturbated shale

• "proximal offshore deposits (prodelta and equivalents; Danke et al., 1993) ... foreland basin subsidence and tectonoeustatic sea-level rise resulted in widespread marine flooding of the Western Interior U.S."

Size classes: macrofossils, mesofossils, microfossils

Preservation: mold/impression, original aragonite, original calcite

Collection methods: bulk,

Primary reference: B. S. Sageman and C. R. Bina. 1997. Diversity and Species Abundance Patterns in Late Cenomanian Black Shale Biofacies, Western Interior, U.S. Palaios 12:449-466 [L. Ivany/P. Wall/P. Wall]more details

Purpose of describing collection: paleoecologic analysis

PaleoDB collection 44284: authorized by Linda Ivany, entered by Patrick Wall on 08.09.2004

Creative Commons license: CC BY (attribution)

Taxonomic list

Cephalopoda
 Ammonitida - Acanthoceratidae
Metoicoceras cf. mosbyense Cobban 1953 ammonite
"Calycoceras cf. naviculare" = Calycoceras (Calycoceras) naviculare Mantell 1822 ammonite
Scaphopoda
 Gadilida - Gadilidae
Bivalvia
 Ostreida - Gryphaeidae
 Pectinida - Plicatulidae
"Plicatula cf. ferryi" = Plicatula (Plicatula) ferryi Coquand 1862 scallop
 Poromyida - Poromyidae
"Psilomya cf. concentrica" = Liopistha (Psilomya)
"Psilomya cf. concentrica" = Liopistha (Psilomya) clam
 Cardiida - Mactridae
? Geltena sp. Stephenson 1946 clam
 Carditida - Astartidae
Astarte sp. n. sp.
Astarte sp. n. sp. Sowerby 1816 clam
Gastropoda
 Sorbeoconcha - Cerithiopsidae
Cerithiopsis sp. Hanley 1849 snail
 Sorbeoconcha - Naticidae
 Cerithioidea - Turritellidae
Turritella sp. Lamarck 1799 turret shell