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Permian dicynodonts from Laos



From: Ben Creisler
bcreisler@gmail.com

Permian not Mesozoic but may be of interest:


Antoine Bercovici, Sylvie Bourquin, Jean Broutin, Jean-Sébastien
Steyer, Bernard Battail, Monette Véran, Renaud Vacant, Bounxou
Khenthavong & Sotsy Vongphamany (2012)
Permian Continental Paleoenvironments In Southeastern Asia: New
Insights From The Luang Prabang Basin (Laos).
Journal of Asian Earth Sciences (advance online publication)
doi: http://dx.doi.org/10.1016/j.jseaes.2012.08.019
http://www.sciencedirect.com/science/article/pii/S1367912012003720?v=s5

In Laos (Southeastern Asia), Late Paleozoic sediments were identified
by early French explorations across Indochina during the late 19th
century (Pavie missions), but little work was undertaken to
characterize the sedimentological and stratigraphical context until
now. From detailed sedimentological and paleontological studies, we
propose an interpretation of the depositional environment and of the
stratigraphic context of series located on the right bank of the
Mekong River in the Luang Prabang Basin where three main formations
were described. The silicoclastic Red Claystone Formation, attributed
to alluvial plain environment, contains large fragments of
unidentified dicynodonts. The Limestones and Sandstones Formation
preserves a new macrofloral assemblage displaying affinities with
Middle to Late Permian Cathaysian floras of South China. This
assemblage occurs as an intercalation within marine calcareous
sandstones that have yielded a marine fauna, including the ammonoid
Pseudotirolites sp. which indicates a Late Permian (Changhsingian)
age. The well-developed Purple Claystones Formation yielded an
abundant and well preserved Late Permian fauna composed of a
carnivorous amphibian and numerous Dicynodon cranial and postcranial
elements. This formation shows a vertical evolution from braided river
to alluvial plain with sheet-flood sand bed and bed-load rivers, with
a constant supply of volcanic clasts. Results from the analysis of the
paleontological associations in the Luang Prabang Basin suggest that a
continental communication between Laurussia and the Indochina Block
existed during the Permian, allowing for migration of the terrestrial
Dicynodon fauna.