MNA 854-1, Ward Terrace: Rhaetian - Hettangian, Arizona
collected by S. Thybony 1986
List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
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Reptilia
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Syntarsus sp.
Raath 1969
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Lucas and Heckert 2001 | 2 specimens | ||||||||
| MNA V2588, MNA V1968 | ||||||||||
| see common names | ||||||||||
Geography
| Country: | United States | State/province: | Arizona | County: | Coconino |
| Coordinates: | 35.9° North, 111.3° West (view map) | ||||
| Paleocoordinates: | 15.0° North, 50.6° West | ||||
| Basis of coordinate: | based on nearby landmark | ||||
| Geographic resolution: | small collection |
Time
| Key time interval: | Rhaetian - Hettangian |
| Age range of interval: | 208.50000 - 199.50000 m.y. ago |
Stratigraphy
| Geological group: | Glen Canyon | Formation: | Moenave | Member: | Dinosaur Canyon |
| Stratigraphic resolution: | bed | ||||
| Stratigraphy comments: Most of the Moenave Formation is the Dinosaur Canyon Member. In the Moenave type section, near Tuba City, Arizona, all of the Moenave section is Dinosaur Canyon Member, as it is throughout the Moenave outcrop belt along the Echo Cliffs and Ward's Terrace of northern Arizona. However, north of the Grand Canyon in Arizona and in southwestern Utah, the upper part of the Moenave Formation is lacustrine strata. These strata are the Whitmore Point Member.
Lucas et al. (2011: Palaeo3 302: 194-205) proposed, on the basis of multiple lines of biostratigraphic evidence, that the Triassic–Jurassic boundary is placed within the middle part of the Whitmore Point Member of the Moenave Formation where this member is present, and high in the Dinosaur Canyon Member elsewhere. The "Whitmore Point assemblage" of vertebrate taxa, earliest Jurassic (Hettangian) in age. The underlying "Dinosaur Canyon assemblage", is latest Triassic (Rhaetian) in age. Lucas et al. (2011) note that these fossils were collected from the Dinosaur Canyon assemblage | |||||
Lithology and environment
| Primary lithology: | siltstone |
| Secondary lithology: | fine sandstone |
| Includes fossils? | Y |
| Lithology description: Dinosaur Canyon Member is mostly a mixture of water-laid and eolian siltstone and sandstone that is 60-100 m thick; fossils from a "fine-grained sandstone" | |
| Environment: | interdune |
| Geology comments: "part of an interdunal wadi sequence" | |
Taphonomy
| Modes of preservation: | body |
| Degree of concentration: | dispersed |
| Size of fossils: | macrofossils |
| Preservation of anatomical detail: | medium |
| Associated major elements: | all |
| Fragmentation: | frequent |
| Temporal resolution: | snapshot |
Collection methods and comments
| Collection methods: | selective quarrying,surface (float),surface (in situ),mechanical,field collection | ||
| Reason for describing collection: | taxonomic analysis | ||
| Collectors: | S. Thybony | Collection dates: | 1986 |
| Collection method comments: discovered by Scott Thybony | |||
Metadata
| Database number: | 52086 | ||
| Authorizer: | M. Carrano | Enterer: | K. Maguire |
| Modifier: | G. Varnham | Research group: | vertebrate |
| Created: | 2005-07-20 14:23:31 | Last modified: | 2022-04-26 05:42:51 |
| Access level: | the public | Released: | 2005-07-20 14:23:31 |
| Creative Commons license: | CC BY |
Reference information
Primary reference:
| 14723. | ETE | M. Morales. 1994. First dinosaur body fossils from the Lower Jurassic Dinosaur Canyon Member, Moenave Formation of northeastern Arizona. Journal of Vertebrate Paleontology 14(3, suppl.):39A [M. Carrano/M. Carrano] |
Secondary references:
| 13958 | ETE | S. G. Lucas and A. B. Heckert. 2001. Theropod dinosaurs and the Early Jurassic age of the Moenave Formation, Arizona-Utah, USA. Neues Jahrbuch für Geologie und Paläontologie Monatshefte 2001(7):435-448 [M. Carrano/K. Maguire/M. Carrano] |