New Oligocene vertebrate localities from Northern Kenya (Turkana basin)

Abstract

International audienc

Stratigraphy, sedimentology and diagenetic evolution of the Lapur Sandstone in northern Kenya: Implications for oil exploration of the Meso-Cenozoic Turkana depression

“…Macroscopic observations on hand specimens and microscopic studies on thin sections were performed at the Petrography Lab- Murray-Hughes (1933), outcropping in the northern and central segments of the Kenya Rift (redrawn from Tiercelin et al, 2004). These formations are, from north to south, respectively: (1) the Lubur Series (Arambourg, 1935(Arambourg, , 1943 (here named the Lapur Sandstone; Thuo, 2009) at the northwest end of Lake Turkana; (2) the Muruanachok Sandstone to the west of Lake Turkana (Walsh and Dodson, 1969;Morley et al, 1992Morley et al, , 1999dWescott et al, 1993;Thuo, 2009;Tiercelin et al, 2011); (3) the Lokone Sandstone and Auwerwer Sandstone to the southwest of Lake Turkana (Lokichar Basin) (Boschetto et al, 1992;Morley et al, 1999d;Tiercelin et al, 2004;Vincens et al, 2006;Ducrocq et al, 2010); (4) the Lariu sandstones and the Mount Porr Sandstone (also known as the Sera Iltomia Formation) at the southwest and southeast ends of Lake Turkana, respectively (Savage and Williamson, 1978;Williamson and Savage, 1986;Wescott et al, 1993;Tiercelin et al, 2004); (5) the Kimwarer and Kamego Formations in the Kerio and Baringo Basins in the central Kenya Rift (Walsh, 1969;Lippard, 1972;Chapman et al, 1978;Ego, 1994;Renaut et al, 1999;Tiercelin et al, 2004Tiercelin et al, , 2011. oratory of the FRE 3298 CNRS ''Géosystèmes'', Lille 1 University, France.…”

“…This region has been described as the most important area in eastern Africa for studying a long-lived segment of the East African Rift System and how it interacted with the Cretaceous-Paleogene southern Sudan and Anza rifts (Fairhead, 1986;Reeves et al, 1987;Greene et al, 1991;Morley et al, 1999c). The present-day Lake Turkana Basin is part of a string of major N-S oriented half-grabens that developed between Cretaceous and Eocene-Oligocene to Pliocene-Pleistocene times (Mugisha et al, 1997;Morley et al, 1999a,d;Hautot et al, 2000;Tiercelin and Lezzar, 2002;Tiercelin et al, 2004Tiercelin et al, , 2011Ducrocq et al, 2010) (Fig. 1c).…”

Hippos stem from the longest sequence of terrestrial cetartiodactyl evolution in Africa

“…However, the discovery of Epirigenys can help to favour only one scenario. Epirigenys, dated from the late early Oligocene or early late Oligocene 19 , is related to a group of archaic bothriodontines that expanded from Asia to Africa as early as the latest Eocene 21 (Fig. 3).…”

“…Discoveries of such deposits most often provide important evidence for the evolutionary history of mammals, in particular for primates [12][13][14] . And yet, despite several new early to late Oligocene sites found during the last decade 12,[15][16][17][18][19] , the anthracothere diversity of Paleogene AraboAfrica remained as described by Schmidt 20 and revised by Ducrocq 21 for the Fayum depression: four species of Bothriogenys and one of Qatraniodon 22 .…”

“…Bothriogenys by Ducrocq et al 19 , was discovered at Lokone, Turkana Basin and northern Kenya in deposits dated to the late early Oligocene or the early late Oligocene 19 . This anthracothere is the most abundant large mammal at Lokone, where it is associated with small taxa considered as relic species (for example, the phiomorph rodent Turkanamys hexalophus 23 and the parapithecid primate Lokonepithecus manai 13 ).…”