Arroyo San Lazaro8 (Cretaceous of Mexico)

Where: Nuevo Leon, Mexico (25.8° N, 99.6° W: paleocoordinates 22.7° N, 52.6° W)

• coordinate based on political unit

• small collection-level geographic resolution

When: Valanginian (139.8 - 132.9 Ma)

Environment/lithology: limestone

• limestone, thin-bedded, nodular-veined and fractured, dense, blue-grey; some thin interbedded ashy and shaly marls; ammonites abundant, esp. Rogersites and Thurmannites

Preservation: original calcite

Primary reference: R. W. Imlay. 1937. Lower Neocomian fossils from the Miquihuana region, Mexico. Journal of Paleontology 11(7):552-574 [M. Patzkowsky/K. Layou/J. Alroy]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 2133: authorized by Mark Patzkowsky, entered by Karen Layou on 22.06.1999

Creative Commons license: CC BY (attribution)

Taxonomic list

Cephalopoda
 Ammonitida - Olcostephanidae
"Rogersites paucicostatus" = Olcostephanus paucicostatus, "Rogersites tenuicostatus" = Olcostephanus atherstoni, "Rogersites prorsiradiatus" = Olcostephanus atherstoni, "Rogersites filifer" = Olcostephanus atherstoni, "Rogersites bakeri" = Olcostephanus atherstoni, "Rogersites sanlazarensis" = Olcostephanus sanlazarensis, Valanginites tijerensis
"Rogersites paucicostatus" = Olcostephanus paucicostatus Imlay 1937 ammonite
"Rogersites tenuicostatus" = Olcostephanus atherstoni Sharpe 1856 ammonite
"Rogersites prorsiradiatus" = Olcostephanus atherstoni Sharpe 1856 ammonite
"Rogersites filifer" = Olcostephanus atherstoni Sharpe 1856 ammonite
"Rogersites bakeri" = Olcostephanus atherstoni Sharpe 1856 ammonite
"Rogersites sanlazarensis" = Olcostephanus sanlazarensis Imlay 1937 ammonite
Valanginites tijerensis Imlay 1937 ammonite
 Ammonitida - Neocomitidae
Favrella sp. Douvillé 1909 ammonite
Thurmannites angusticostatus Imlay 1937 ammonite
Bivalvia
 Arcida - Glycymerididae
? Trigonarca sp. Conrad 1862 clam
originally entered as "Trigonarca? sp."