Railroad Cut, Bed 4, Kaibab Formation, Walnut Canyon (Permian of the United States)

Where: Coconino County, Arizona (35.2° N, 111.6° W: paleocoordinates 9.2° N, 36.6° W)

• coordinate estimated from map

• local area-level geographic resolution

When: "Alpha" Member (Kaibab Formation), Roadian (272.3 - 268.8 Ma)

• 6 feet thick, forms ledge.

• group of beds-level stratigraphic resolution

Environment/lithology: shallow subtidal; shelly/skeletal, brown, silty limestone

• Limestone: very pale brown, silty, very fossiliferous, weathers same colour

Size class: macrofossils

Preservation: mold/impression

Primary reference: H. Chronic. 1952. Molluscan fauna from the Permian Kaibab Formation, Walnut Canyon, Arizona. Geological Society America Bulletin 63(2):95-166 [D. Bottjer/M. Clapham/M. Clapham]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 40000: authorized by David Bottjer, entered by Matthew Clapham on 13.06.2004

Creative Commons license: CC BY (attribution)

Taxonomic list

Bivalvia
 Arcida - Parallelodontidae
"Grammatodon politus" = Grammatodon (Cosmetodon) politus
"Grammatodon politus" = Grammatodon (Cosmetodon) politus Girty 1909 clam
 Pectinida - Aviculopectinidae
Aviculopecten kaibabensis Newell 1938 scallop
 Ostreida - Bakevelliidae
Bakevellia prora Chronic 1952 oyster
 Mytilida - Mytilidae
Promytilus retusus Chronic 1952 mussel
 Cardiidia - Sanguinolitidae
? Sanguinolites sp. M'Coy 1844 clam
 Cardiida - Kalenteridae
"Pleurophorus albequus" = Permophorus albequus
"Pleurophorus albequus" = Permophorus albequus Beede 1907 clam
 Modiomorphida - Modiomorphidae
Goniophora cristata Chronic 1952 clam
 Trigoniida - Schizodidae
Kaibabella curvilenata Chronic 1952 clam
 Nuculida - Nuculidae
"Palaeonucula levatiformis" = Nuculavus levatiformis
"Palaeonucula levatiformis" = Nuculavus levatiformis Walcott 1884 nut clam
 Protobranchia - Nuculanidae
"Nuculana obesa" = Polidevcia obesa
"Nuculana obesa" = Polidevcia obesa White 1879 pointed nut clam
Gastropoda
 Trochonematoidea - Lophospiridae
Platyworthenia delicata Chronic 1952 snail
 Euomphalina - Microdomatidae
Glyptospira cristulata n. gen. Chronic 1952 snail
 Bellerophontida - Bellerophontidae
Retispira undulata n. sp. Chronic 1952 snail
Scaphopoda
 Dentaliida - Prodentaliidae
"Plagioglypta canna" = Prodentalium canna
"Plagioglypta canna" = Prodentalium canna White 1874 tusk shell
Strophomenata
 Productida - Productidae
"Dictyoclostus bassi" = Peniculauris bassi
"Dictyoclostus bassi" = Peniculauris bassi McKee 1938