Cerro Rajon, type 2 buildup, Puerto Blanco Formation, unit 3, Caborca (Cambrian of Mexico)

Also known as Reef 1789

Where: Mexico (30.4° N, 112.0° W: paleocoordinates 4.3° S, 102.8° W)

• coordinate based on nearby landmark

• small collection-level geographic resolution

When: unit 3 Member (Puerto Blanco Formation), Botomian (516.0 - 512.9 Ma)

• 2 beds within interval CR-2 in the middle part of unit 3

• group of beds-level stratigraphic resolution

Environment/lithology: reef, buildup or bioherm; lithified reef rocks

• isolated patch reefs and biostromes in a back-shoal, lagoonal setting
• Girvanella-dominated framework in which archaeocyaths built small, scattered bioconstructions

Size classes: macrofossils, mesofossils

Collection methods: peel or thin section,

• internal and lateral sediment contains a rich fauna represented by trilobites, hyoliths, brachiopods, Chancelloria, echinoderm plates and helcionellacean mollusks

Primary reference: F. Debrenne, A. Gandin, and S. M. Rowland. 1989. Lower Cambrian bioconstructions in Northwestern Mexico (Sonora). Depositional setting, paleoecology and systematics of Archaeocyaths. GĂ©obios 22(2):137-195 [W. Kiessling/U. Merkel/P. Wagner]more details

Purpose of describing collection: paleoecologic analysis

PaleoDB collection 62865: authorized by Wolfgang Kiessling, entered by Uta Merkel on 31.07.2006

Creative Commons license: CC BY (attribution)

Taxonomic list

 Archaeocyathida - Dictyocyathidae
Dictyocyathus sp. archaeocyath sponge
sp. 1
Retilamina sp. Debrenne and James 1981 archaeocyath sponge
 Archaeocyathida - Claruscoscinidae
Stevocyathus elictus n. gen. n. sp.
Stevocyathus elictus n. gen. n. sp. archaeocyath sponge
 Archaeocyathida - Archaeopharetridae
Protopharetra sp. Bornemann 1884 archaeocyath sponge
 Archaeocyathida - Archaeocyathidae
"Palmericyathellus undatus n. sp." = Sigmofungia archaeocyath sponge
Pycnoidocyathus eminetus n. sp. archaeocyath sponge
Arrythmocricus macdamensis archaeocyath sponge
Archaeocyathus sp. Billings 1861 archaeocyath sponge
Archaeocyathus arborensis Okulitch 1954 archaeocyath sponge
 Archaeocyathida - Metacyathidae
Metaldetes cf. fischeri archaeocyath sponge
 Archaeocyathida - Loculicyathidae
Paranacyathus polycladus archaeocyath sponge
 Ajacicyathida - Ethmophyllidae
Aulocricus arellani archaeocyath sponge
Parethmophyllum cooperi archaeocyath sponge
Cordilleracyathus meridianus n. sp. archaeocyath sponge
 Ajacicyathida - Ajacicyathidae
? Rotundocyathus pusillus n. sp. archaeocyath sponge
 Ajacicyathida - Sajanocyathidae
Palmericyathus americanus archaeocyath sponge
 Ajacicyathida - Tumulocyathidae
"Tumulocyathellus minor n. sp." = Plicocyathus
"Tumulocyathellus minor n. sp." = Plicocyathus archaeocyath sponge
  - Ludloviaceae
Epiphyton sp. Bornemann 1886
  - Chabakoviacea
Renalcis sp. Vologdin 1932
 Oscillatoriales - Girvanellaceae
Girvanella sp. Nicholson and Etheridge 1878