Downs Quarry, MNA 207-10: Norian, Arizona
collected by L. Jacobs, P. Murray

List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
Chondrichthyes
Tannenbaum 1983 1 element
Chondrichthyes - Xenacanthiformes - Xenacanthidae
Xenacanthus moorei (Woodward 1889)
11 elements
Osteichthyes
Tannenbaum 1983 1 element
Tannenbaum 1983 2 elements
Tannenbaum 1983 1 element
Tannenbaum 1983 1 element
Tannenbaum 1983 1 element
Tannenbaum 1983 1 element
"fish?"
Tannenbaum 1983 1 element
"fish?"
Coelacanthimorpha - Coelacanthiformes - Coelacanthidae
Tannenbaum 1983 1 element
Ceratodontidae
Cynodontia
Tannenbaum 1983 1 specimen
Reptilia
Tannenbaum 1983 6 specimens
Reptilia - Tanystropheidae
1 specimen
Reptilia - Fabrosauridae
Reptilia
Long and Murry 1995 8 elements
MNA Pl. 2708, 3081, 3125, cervical centra. MNA Pl. 3071, 3073, 3079, dorsal centra. MNA Pl. 2445, posterior dorsal. MNA Pl. 2746, sacral
3 specimens
MNA Pl. 3077, sacrum. MNA V3715, dorsal centrum. MNA Pl. 2694, proximal femur
Reptilia - Parasuchidae
    = Paleorhinus sp. Williston 1904
Long and Murry 1995
MNA V3728, portion of snout
Long and Murry 1995 38 specimens
MNA V3732, Pl. 2731, 3072, V3736, V3733, V3726, Pl. 3062, Pl. 3069, Pl. 2738, Pl. 2741, V3734, Pl. 3055, Pl. 3056, V3665, Pl. 2736, Pl. 3088, Pl. 2680, V3601, Pl. 3054, Pl. 3057, Pl. 3070, V3727, Pl. 3059, V3667, Pl. 3087, 3097, 2730, 3086, 3063, 3064, 3058, 2740, 3060, 3103, 3085, 3093, 3080, 2742
1 individual
Long and Murry 1995
MNA Pl. 2675, braincase. MNA V3698, left squamosal. MNA V3739, quadrate, paroccipital process. MNA V3737, snout
Reptilia
Heckert et al. 2007 1 specimen
MNA 3202, osteoderms
Long and Murry 1995 5 specimens
MNA V3714, Pl. 3066, 3050, 3067, 3113, plates
Long and Murry 1995 16 specimens
MNA Pl. 2665, 2729, 3090, 3092, 3094, 3091, 2676, 2666, 2667, 2668, 3117, 3129, 2744, 3100, 3101, V3744, postcranial specimens
4 specimens
Long and Murry 1995
?MNA PL. 2710, 3096, 3110, 3127, cervical vertebra and plates
Long and Murry 1995 1 element
MNA V3740, distal right humerus
Hesperosuchus agilis Colbert 1952
1 element
MNA Pl. 3102, radius
Amphibia - Temnospondyli - Metoposauridae
Metoposaurus sp. Lydekker 1890
Long and Murry 1995
MNA Pl. 2683, 2697, dermal bone fragments. MNA Pl. 2864, plate. MNA V3675, vertebral centrum
Long and Murry 1995
MNA Pl. 2732, vertebrae
Palaeonisciformes - Redfieldiidae
Redfieldiidae indet. Hutchinson 1973
Tannenbaum 1983
Lasalichthyes sp. or Synorichthyes sp. (ref 10591)
Palaeonisciformes - Palaeoniscidae
Tannenbaum 1983
cf. Turseodus sp. Leidy 1857
Tannenbaum 1983
Actinopteri - Semionotiformes - Semionotidae
Actinopteri - Perleidiformes - Colobodontidae
Pholidopleuriformes - Pholidopleuridae
Tannenbaum 1983 2 elements
unclassified
Tannenbaum 1983
Branchiopoda
? Branchiopoda indet. Latreille 1817
unclassified
see common names

Geography
Country:United States State/province:Arizona County:Apache
Coordinates: 34.4° North, 109.5° West (view map)
Paleocoordinates:9.9° North, 37.4° West (Wright 2013)
Basis of coordinate:stated in text
Geographic resolution:outcrop
Time
Period: Triassic Epoch: Late Triassic
Stage: Norian 10 m.y. bin: Triassic 4
Key time interval: Norian
Age range of interval: 227.3 - 205.7 m.y. ago
Age estimate: 213.44 ± 5.16 to 209.95 ± 0.44 Ma (paleomagnetic)
Stratigraphy
Formation:Chinle Member:Petrified Forest
Stratigraphic resolution:bed
Stratigraphy comments: 3 m above upper level in the Placerias Quarry; also placed in the Petrified Forest Mb of the Chinle Fm. Also referred to the Bluewater Creek Formation

Kent et al. Petrified Forest Member of the Chinle formation falls between magneto zones PF4n and PF2n (roughly 209.95–213.44Ma)
Lithology and environment
Primary lithology:concretionary "carbonate"
Includes fossils?Y
Lithology description: Many bones "are encased in gray carbonate concretions which have an odor of hydrogen sulfide when broken."
Environment:pond
Geology comments: "low-energy depositional environments", like the Placerias Quarry (i.e. pond or marsh)
Taphonomy
Modes of preservation:body,concretion,coprolite
Degree of concentration:concentrated
Size of fossils:macrofossils,mesofossils,microfossils
Preservation of anatomical detail:excellent
Articulated whole bodies:none
Associated major elements:none
Disassociated major elements:many
Disassociated minor elements:many
Fragmentation:frequent
Spatial resolution:parautochthonous
Collection methods and comments
Collection excludes:some microfossils
Collection methods:bulk,sieve,field collection
Rock censused:5800 kg
Reason for describing collection:general faunal/floral analysis
Collectors:L. Jacobs, P. Murray
Metadata
Database number:39219
Authorizer:M. Carrano, R. Butler Enterer:M. Carrano, R. Butler
Modifier:G. Varnham Research group:vertebrate
Created:2004-05-24 11:12:03 Last modified:2025-02-22 15:12:02
Access level:the public Released:2004-05-24 11:12:03
Creative Commons license:CC0
Reference information

Primary reference:
10591. L. L. Jacobs and P. A. Murry. 1980. The vertebrate community of the Triassic Chinle Formation near St. Johns, Arizona. In L. L. Jacobs (ed.), Aspects of Vertebrate History: Essays in Honor of Edwin Harris Colbert 55–71 [M. Carrano/M. Carrano/M. Carrano]

Secondary references:

19347ETE A. R. Fiorillo, K. Padian, and C. Musikasinthorn. 2000. Taphonomy and depositional setting of the Placerias Quarry (Chinle Formation: Late Triassic, Arizona). Palaios 15:373-386 [M. Carrano/M. Carrano]
31129 A. B. Heckert and S. G. Lucas. 2002. Acaenasuchus geoffreyi (Archosauria: Aetosauria) from the Upper Triassic Chinle Group: juvenile of Desmatosuchus haplocerus. In A. B. Heckert, S. G. Lucas (eds.), Upper Triassic Stratigraphy and Paleontology. New Mexico Museum of Natural History and Science Bulletin 21:205-214 [R. Butler/R. Butler]
24941ETE A. B. Heckert and S. G. Lucas. 2006. Micro- and small vertebrate biostratigraphy and biochronology of the Upper Triassic Chinle Group, southwestern USA. In J. D. Harris, S. G. Lucas, J. A. Spielmann, M. G. Lockley, A. R. C. Milner, J. I. Kirkland (eds.), The Triassic-Jurassic Terrestrial Transition. New Mexico Museum of Natural History and Science Bulletin 37:94-104 [M. Carrano/M. Carrano/P. Wagner]
43558 A. B. Heckert, J. A. Spielmann, S. G. and A. P. Hunt. 2007. Biostratigraphic utility of the Upper Triassic aetosaur Tecovasuchus (Archosauria: Stagonolepididae), an index taxon of St. Johnsian (Adamanian: late Carnian) time. New Mexico Museum of Natural History and Science Bulletin 41:51-57 [R. Butler/R. Butler]
63048 L. L. Jacobs. 1980. Additions to the Triassic vertebrate fauna of Petrified Forest National Park, Arizona. Journal of the Arizona-Nevada Academy of Science 15(1):12 [M. Carrano/M. Carrano]
30645ETE L. L. Jacobs. 1985. Small vertebrate fossils from the Chinle Formation (Triassic) near St. Johns, Arizona. National Geographic Society Research Reports (1979) 20:417-419 [M. Carrano/M. Carrano]
79159 D. V. Kent, P. E. Olsen, C. Lepre, C. Rasmussen, R. Mundil, G. E. Gehrels, D. Giesler, R. B. Irmis, J. W. Geissman and W. G. Parker. 2019. Magnetochronology of the Entire Chinle Formation (Norian Age) in a Scientific Drill Core From Petrified Forest National Park (Arizona, USA) and Implications for Regional and Global Correlations in the Late Triassic. Geochemistry, Geophysics, Geosystems [P. Mannion/G. Varnham]
14122ETE R. A. Long and P. A. Murry. 1995. Late Triassic (Carnian and Norian) Tetrapods from the Southwestern United States. New Mexico Museum of Natural History and Science Bulletin 4:1-254 [M. Carrano/M. Carrano/P. Wagner]
25567ETE S. G. Lucas, A. B. Heckert, and A. P. Hunt. 1997. Stratigraphy and biochronological significance of the Late Triassic Placerias quarry, eastern Arizona (U.S.A.). Neues Jahrbuch für Geologie und Paläontologie Abhandlungen 203(1):23-46 [M. Carrano/M. Carrano]
12930ETE P. A. Murry and R. A. Long. 1989. Geology and paleontology of the Chinle Formation, Petrified Forest National Park and vicinity, Arizona and a discussion of vertebrate fossils of the southwestern Upper Triassic. In S. G. Lucas and A. P. Hunt (eds.), Dawn of the Age of Dinosaurs in the American Southwest, New Mexico Museum of Natural History, Albuquerque 29-64 [M. Carrano/M. Carrano/M. Carrano]
11081ETE F. A. Tannenbaum. 1983. The microvertebrate fauna of the Placerias and Downs Quarries, Chinle Formation (Upper Triassic) near St. Johns, Arizona. University of California, Berkeley 1-117 [M. Carrano/M. Carrano/M. Carrano]