Zuni Well Mound, PFV 215 (Triassic of the United States)

Also known as PEFO

Where: Apache County, Arizona (35.1° N, 109.8° W: paleocoordinates 10.8° N, 48.3° W)

• coordinate based on nearby landmark

When: Petrified Forest Member (Chinle Formation), Norian (228.0 - 208.5 Ma)

• "Approximately 54 meters below a prominent tuffaceous sandstone bed known as the Black Forest Bed. Riggs et al. (2003) have determined a maximum age for this bed, and thus a minimum age for the quarries, of 213 +/- 1.7 based on U-Pb ages of detrital zircons."

• bed-level stratigraphic resolution

Environment/lithology: fine channel fill; paleosol/pedogenic, gray siliciclastic sediments and nodular, gray, red siltstone

• "deposited in a localized, scoured depression, such as an abandoned channel or chute where flow velocities were limited"
• "in gray (N/5) claystone and variegated red (10R 3/1), purple (10R 5/2), and gray (N/5) clayey siltstone...Bones at the site primarily come from the gray (N/5) claystone layer that disconformably overlies the IHS deposits. The horizon bears abundant fine filled cracks, moderate to strong prismatic structure, slickensides, and pseudoanticlines (Fig. 8A). Thin sections from this horizon reveal well-developed striated b-fabric formed during alternating shrinking and swelling of the soil. Ped interiors are depleted in iron and manganese, whereas ped exteriors have accumulated ferric iron and manganese (III); this pattern develops during fluctuation of the water table. This claystone layer grades upward into variegated red (10R 3/1), purple (10R 5/2), and gray (N/5) clayey siltstone at the top of the exposure, upon which gastropod and bivalve shells can be found. This layer contains light greenish gray (5GY 7/1) mottles and numerous carbonate nodules (1.0–5.0 cm). Cracks filled with sandy and silty material are evident in thin section, but no b-fabric has developed, showing that this layer was not altered by pedoturbation. No rhizoliths or burrows were observed in this layer, suggesting that sediment was deposited rapidly."

Size class: macrofossils

Collection methods: quarrying,

• PEFO: Petrified Forest National Park, Arizona

Primary reference: W. G. Parker and B. J. Barton. 2008. New information on the Upper Triassic archosauriform Vancleavea campi based on new material from the Chinle Formation of Arizona. Palaeontologia Electronica 11(3):14A [R. Butler/R. Butler]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 92811: authorized by Richard Butler, entered by Richard Butler on 30.11.2009, edited by Bryan Gee and Matthew Carrano

Creative Commons license: CC BY (attribution)

Taxonomic list

Gastropoda
  -
Gastropoda indet.2 Cuvier 1795 snail
Bivalvia
  -
Bivalvia indet.2 Linnaeus 1758 clam
Osteichthyes
 Dipnoi -
Dipnoi indet.2 lungfish
Amphibia
 Temnospondyli -
Stereospondyli indet.2 von Zittel 1887 tetrapod
 Temnospondyli - Metoposauridae
"Koskinonodon perfectus" = Anaschisma browni1, Apachesaurus gregorii2
"Koskinonodon perfectus" = Anaschisma browni1 Branson 1905 tetrapod
PEFO 35392, skull and intercentra
Apachesaurus gregorii2 Hunt 1993 tetrapod
Reptilia
  -
Reptilia indet.2 Laurenti 1768 reptile
 Archosauria -
Archosauria indet.2 Cope 1869 archosaur
 Pseudosuchia -
Revueltosaurus callenderi5 Hunt 1989 aetosaur
Teeth
 Ornithodira -
Ornithodira indet.3 Gauthier 1986 ornithodiran
PEFO 36741, left metatarsal I
 Dinosauria -
Dinosauria indet.3 dinosaur
PEFO 34863, left femur (proximal end)
 Diapsida - Doswelliidae
Vancleavea campi4 Long and Murry 1995 archosauromorph
PEFO 31202, left femur; PEFO 34035, partial skeleton