New data on the palaeontology and sedimentology of the Lower Jurassic Lisbon Formation (Karoo Supergroup), Ellisras Basin, South Africa

Abstract

Published records on the palaeontology of the Lower Jurassic Lisbon Formation in the Ellisras Basin (a South African continuation of the Botswana Kalahari Karoo Basin) are virtually non-existent. Here we review the geology of this extremely poorly exposed unit, and describe a newly discovered ichnofossil and fossil vertebrate association, consisting of constructed structures resembling termitaria as well as of basal sauropodomorph remains. Our paleontological and sedimentological analyses permit a direct bioand lithostratigraphic correlation of the Lisbon Formation at farm Lisbon with the upper part of the Elliot Formation in the main Karoo Basin as well as other Lower Jurassic continental red bed successions throughout southern Africa. We tentatively suggest that the formation (especially its upper part) was deposited in a dryland setting with well-drained soils that at least episodically supported some flora and a fauna probably dominated by basal sauropodomorphs.