The Vester Formation is a geologic formation in Oregon which preserves fossils dating back to the Triassic period. The partial skeleton of a new genus of basal thalattosaur has been recovered from the Brisbois Member of this formation.[1] The Brisbois Member, which dates to between the Carnian and Norian, is a marine sequence primarily composed of fine-grained clastic sedimentary rocks with fissile mudstones of black, green or gray variety broken up by widely spaced intervals of calcirudite beds and calcareous conglomerate.[2] The formation formed between two parallel island arcs, that of the Baker Terrane and the Olds Ferry Terrane. The formation mostly consists of reworked chert grains from the Baker Terrane.[3] In addition to the remains of the basal thalattosaur, fragmentary and undescribed remains exist of an ichthyosaur, archosaur, and a hybodontid shark as well as many invertebrate fossils.[1]

Vester Formation
Stratigraphic range: Ladinian - Norian
TypeFormation
Unit ofOlds Ferry Terrane
Sub-unitsBrisbois Member
AreaCentral Oregon
Location
Coordinates44.118° N, 119.483° W
RegionOregon
CountryUnited States

See also edit

References edit

  1. ^ a b Metz, Eric T. (2019). Description, phylogenetic analysis and taphonomy of a new Thalattosaur from the Brisbois member of the Vester Formation (Carnian/Norian) of central Oregon (ms thesis). University of Alaska Fairbanks.
  2. ^ Dickinson and Vigrass, 1965
  3. ^ Dorsey and LaMaskin, 2007

Sources edit

  • Various Contributors to the Paleobiology Database. "Fossilworks: Gateway to the Paleobiology Database". Retrieved 17 December 2021.