Marshall Creek, Spokane (Miocene of the United States)

Where: Washington (47.6° N, 117.4° W: paleocoordinates 48.4° N, 114.2° W)

• coordinate based on nearby landmark

• outcrop-level geographic resolution

When: Latah Formation, Langhian (16.0 - 13.8 Ma)

• Latah Formation overlies the Grande Ronde basalts (16-15.5 Ma; Barry et al., 2013), although younger parts of the Grande Ronde are absent at some localiies (Nash & Perkins, 2012). It underlies the Saddle Mountain basalts (c. 15 Ma and younger; Barry et al., 2013). Ash beds within the Latah Formation at White Bird, Idaho, are dated to 15.77 Ma (Mascall Tuff), 15.66 Ma (Bully Creek tuff), and an interpolated age of 14.3 Ma (Nash & Perkins, 2012).

• group of beds-level stratigraphic resolution

Environment/lithology: lacustrine - small; lithified mudstone

• Interbedded with Columbia River flood basalts.

Size class: macrofossils

Preservation: mold/impression

Collected by Grant Valentine

• Repository: Washington State Division of Mines Museum, Olympia, Washington

Primary reference: S. E. Lewis. 1969. Fossil insects of the Latah Formation (Miocene) of eastern Washington and northern Idaho. Northwest Science 43:99-115 [M. Clapham/M. Clapham/R. Day]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 97618: authorized by Matthew Clapham, entered by Matthew Clapham on 13.08.2010

Creative Commons license: CC BY (attribution)

Taxonomic list

Insecta
 Odonata - Macromiidae
Epophthalmia biordinata n. sp. Lewis 1969 true dragonfly
M.C. 1