Where: Alaska (61.7° N, 149.0° W: paleocoordinates 68.0° N, 125.0° W)
• coordinate stated in text
• small collection-level geographic resolution
When: Chickaloon Formation, Late/Upper Paleocene to Late/Upper Paleocene (58.7 - 48.6 Ma)
• The Chickaloon Formation was named by Martin and Katz (1912) and covers the greater part of the valley of the Chickaloon River south of Castle Mountain, southern Alaska. The formation consists of fl uviatile and alluvial carbonacous mudstone, siltstone, polymictic sandstone, conglomeratic sandstone, and numerous beds of bituminous coals at least 1500 meters thick (Barnes and Payne 1956, Winkler 1992; Wolfe et al. 1966). Martin and Katz (1912) assigned an age of Tertiary, probably Eocene. Barnes and Payne (1956:14) considered the age to be Paleocene or Eocene. Wolf et al. (1966), based on the flora, considered the Chickaloon Formation as Paleocene. Most recently, Triplehorn et al. (1984) and Winkler (1992) dated volcanic ash partings in the upper part of the Chickaloon at the Evan Jones mine, northwest of Jonesville, using fi ssion-track and radiometric data. Their assigned ages of Paleocene and early Eocene (53.3 ± 1.5 to 55.8 ± 1.7Ma) encompass the Paleocene-Eocene boundary (about 55.5 Ma fi de Berggren et al. 1998). The fossil turtle locality lies near the Matanuska Bluffs U.S. Geological Survey Paleobotany locality 5892 of Wolfe et al. (1966), who considered this section to lie entirely below the coal rich upper part of the formation and thus presumably below the dated beds of Triplehorn et al. (1984). Scott Wing (1999, pers. comm.) regards the flora as late Paleocene and an excellent match for Clarkforkian North American Land Mammal Age (NALMA; 56.35–55.8 Ma fi de Woodburne and Swischer 1995; 56.2–55.5 Ma fi de Prothero 1995).
• bed-level stratigraphic resolution
Environment/lithology: fluvial; carbonaceous mudstone
Size class: macrofossils
Preservation: adpression
Collected by Anthony Milionta, Mike Morrison, and Veronica Cacy during a geology class fi eld trip with instructor Bjarme Holm of Service High School, Anchorage, Alaska in 1994
Primary reference: J. H. Hutchison and A. D. Pasch. 2004. First record of a turtle (Protochelydra, Chelydridae, Testudines) from the Cenozoic of Alaska (Chickaloon Formation, Paleocene–Eocene). PaleoBios 24(1):1-5 [P. Mannion/P. Mannion]more details
Purpose of describing collection: taxonomic analysis
PaleoDB collection 137806: authorized by Philip Mannion, entered by Philip Mannion on 20.12.2012
Creative Commons license: CC BY (attribution)
Taxonomic list
Reptilia | |
Protochelydra cf. zangerli Erickson 1973 turtle UAM No. AK-526-V-01 (a nearly complete but compressed carapace); UCMP 159853 (mold)
| |
unclassified | |
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