USGS Mesozoic D10746, Chispa Summit (Cretaceous of the United States)

Where: Jeff Davis County, Texas (30.7° N, 104.8° W: paleocoordinates 30.9° N, 69.8° W)

• coordinate based on nearby landmark

• outcrop-level geographic resolution

When: Sciponoceras gracile ammonoid zone, Chispa Summit Formation, Late/Upper Cenomanian (99.6 - 93.5 Ma)

• 39 m (128 ft) above base

• bed-level stratigraphic resolution

Environment/lithology: marine; lithified limestone

• Chalky limestone

Size class: macrofossils

Collected by S.C. Hook, W.A. Cobban in 1979; reposited in the USNM

Primary reference: W. A. Cobban. 1988. Tarrantoceras Stephenson and related ammonoid genera from Cenomanian (Upper Cretaceous) rocks in Texas and the western interior of the United States. United States Geological Survey Professional Paper 1473:1-30 [M. Clapham/M. Clapham]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 177097: authorized by Matthew Clapham, entered by Matthew Clapham on 19.03.2016

Creative Commons license: CC BY (attribution)

Taxonomic list

Cephalopoda
 Ammonitida - Scaphitidae
 Ammonitida - Baculitidae
Sciponoceras gracile Shumard 1860 ammonite
 Ammonitida - Acanthoceratidae
Pseudocalycoceras angolaense Spath 1931 ammonite
Metoicoceras geslinianum d'Orbigny 1841 ammonite
"Euomphaloceras (Kanabiceras) septemseriatum" = Euomphaloceras septemseriatum Cragin 1893 ammonite