Gateway to the Paleobiology Database
Mount Dearborn (Triassic of Antarctica)

Where: Victoria Land, Antarctica (77.2° S, 160.1° E: paleocoordinates 66.7° S, 86.6° E)

• coordinate stated in text

• small collection-level geographic resolution

When: C Member (Lashly Formation), Carnian (235.0 - 221.5 Ma)

• Palynormorphs taken from one of the bone-bearing samples include spores and pollen consistent with subzone C of the Alisporites Zone of Carnian age. The spore species Craterisporites rotundus defines the base of the eastern Australian Craterisporites rotundus Zone of Carnian age, and occurs in Carnian and Norian rocks in New Zealand.

•Specimens found as mudstone clasts on the slope in the upper part of the second fining-upwards cycle of member C of the Lashly Formation. Although it is possible that they are derived from higher in the section they are still likely to be from member C

• group of beds-level stratigraphic resolution

Environment/lithology: "floodplain"; carbonaceous mudstone and conglomeratic sandstone

• "deposition occurred in channels and on floodplains of a meandering stream system"
• "Lashly member C consists of fining-upward cycles of medium- to fine-grained sandstone grading upward into carbonaceous siltstone and mudstone, and thin coal beds. Quartz pebbles and cobbles and mudstone clasts occur near the base of major sandstone units. Irregular lenses of coal occur along bedding planes and over large scours. Dicroidium fronds and other plant fragments are common in carbonaceous beds."

Size class: macrofossils

Collected by Hammer et al. in 1999

Collection methods: surface (float),

Primary reference: W. R. Hammer, J. W. Collinson, R. A. Askin and W. J. Hickerson. 2004. The first Upper Triassic vertebrate locality in Antarctica. Gondwana Research 7(1):199-204 [R. Butler/R. Butler] more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 107212: authorized by Richard Butler, entered by Richard Butler on 02.04.2011

Creative Commons license: CC BY (attribution)