R63. Cerro Rajón (Cambrian of Mexico)

Where: Mexico (30.4° N, 111.9° W: paleocoordinates 6.1° S, 105.0° W)

When: Unit 2 Member (Puerto Blanco Formation), Montezuman (530.0 - 516.0 Ma)

• bed-level stratigraphic resolution

Environment/lithology: transition zone or lower shoreface; lithified, nodular, yellow, calcareous conglomerate

• Represents a southern extension of the Cordilleran miogeocline, rocks may be offset 700 to 800km along a left- lateral fault.
• Unit 2 is ~190 m thick, composed exclusively of sedimentary material and is dominated by shales. Intercalation of fine, laminated sandstone and limestone laminated beds and nodules are present.

Size classes: macrofossils, mesofossils

Collection methods: bulk,

Primary reference: L. Devaere, S. Clausen, J. P. Sosa-Leon, J. J. Palafox-Reyes, B. E. Buitrón-Sánchez and D. Vachard. 2019. Early Cambrian Small Shelly Fossils from northwest Mexico: Biostratigraphic implications for Laurentia. Palaeontologia Electronica 22(2):1-58 [P. Wagner/P. Wagner]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 203107: authorized by Pete Wagner, entered by Pete Wagner on 26.07.2019

Creative Commons license: CC BY (attribution)

Taxonomic list

Coeloscleritophora
 Chancelloriida - Chancelloriidae
Helcionelloida
 Pelagiellida - Pelagiellidae
Pelagiella sp. Matthew 1895
Bivalvia
 Fordillida - Fordillidae
Pojetaia sp. Jell 1980 clam
Hyolitha
 Hyolithida -
Hyolithida sp. Mathew 1962
Parkula bounites Bengtson et al. 1990
 Orthothecida -
"Cupitheca cf. mira" = Cupittheca mira, Petasotheca sp.
"Cupitheca cf. mira" = Cupittheca mira He 1977
Petasotheca sp. Landing and Bartowski 1996
Microdictyon
  -
 Hyolithelminthida - Hyolithellidae
Hyolithellus spp. Billings 1872