SMU 3-1, Eggshell arch (Jurassic to of the United States)

Where: Arizona (36.7° N, 110.8° W: paleocoordinates 23.9° N, 48.5° W)

• coordinate estimated from map

• small collection-level geographic resolution

When: Navajo Sandstone Formation (Glen Canyon Group), Pliensbachian to Pliensbachian (190.8 - 174.1 Ma)

• Navajo Sandstone forms uppermost part of Glen Canyon Group, and is Early Jurassic, but probably not older than Pliensbachian (Irmis 2005. A review of the vertebrate fauna of the Lower Jurassic Navajo Sandstone in Arizona. Mesa Southwest Museum Bulletin 11:55–71)

• bed-level stratigraphic resolution

Environment/lithology: interdune; burrowed, fine-grained sandstone

Size class: macrofossils

Collection methods: SMU: Southern Methodist University

Primary reference: D. A. Winkler, L. L. Jacobs, J. D. Congleton and W. R. Downs. 1991. Life in a sand sea: biota from Jurassic interdunes. Geology 19:889-892 [R. Butler/R. Butler]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 137235: authorized by Richard Butler, entered by Richard Butler on 13.12.2012

Creative Commons license: CC BY (attribution)

Taxonomic list

Osteichthyes
 Therapsida - Tritylodontidae
Tritylodontidae indet. Cope 1884 therapsid
SMU 70527, partial skeleton