Middle and Late Pleistocene mammal fossils of Arabia and surrounding regions: Implications for biogeography and hominin dispersals

Abstract

Plio-Pleistocene faunal turnovers and their implications for hominin dispersals have recently received considerable attention. Exploration and palaeontological study of faunal exchanges has traditionally centred on East Africa, North Africa and the Levant in Southwest Asia. Despite this attention, considerable debate surrounding the timings, rates, and directions of hominin dispersals remain. Notwithstanding its close geographical proximity to these regions and a landmass of over 3 million km2, the Arabian Peninsula has largely been excluded from these discussions, mostly owing to the paucity of its Pleistocene vertebrate record. However, recent palaeoenvironmental studies have demonstrated that Arabia experienced periods of climatic amelioration during the Pleistocene, resulting in the establishment of large, perennial water sources and open-grasslands; conditions vastly different than today. This interpretation is further underpinned by archaeological and palaeontological data, and it is now clear this region is important for understanding faunal and hominin movements between Africa and Eurasia. Examination of the Arabian Middle to Late Pleistocene fossil record in a biogeographical context indicates the composite nature of the Arabian faunal record, with Eurasian and African intrusions present in addition to well-established endemics. Open grassland habitats and taxonomic similarities between Pleistocene Arabia on the one hand, and the Levant and Africa on the other, suggests that hominin dispersal into Arabia did not require significant behavioural and/or technological innovations, while subsequent climatic deterioration likely resulted in hominin retreat/extirpation

A taxonomic and taphonomic study of Pleistocene fossil deposits from the western Nefud Desert, Saudi Arabia

“…Notable is the presence of Hippopotamus, Syncerus, and elephants at several noncontemporaneous sites in the Nefud Desert (Thomas et al, 1998;Stimpson et al, 2016;Groucutt et al, 2018) and elsewhere in Arabia (McClure, 1984), demonstrating that pluvial phases were periodically wet and vegetated enough to allow for the dispersal of large water-dependent taxa into the Arabian interior. Climatic amelioration also facilitated the dispersal of hominins (Groucutt and Petraglia, 2012) and large carnivores (Stimpson et al, 2016;Stewart et al, 2019aStewart et al, , 2019b into Arabia, with the presence of the latter inferred here from tooth-marked bone. While the role that carnivores played in the accumulation and modification of the Arabian fossil deposits remains difficult to assess, it seems likely it was greater than the current observations suggest.…”

“…Thomas et al (1998) also reported remains of a large buffalo from KAM-1, which were provisionally attributed to P. oldowayensis. However, as discussed elsewhere (Stewart et al, 2019b), more recent dating of the KAM-1 palaeolake to the late Pleistocene is suggestive of the younger species S. antiquus. The specimen described here, and probably those reported by Thomas et al (1998), can be provisionally referred to the late Pleistocene S. antiquus.…”

“…Throughout the Pleistocene the Arabian Peninsula underwent a series of pluvial phases that transformed much of its deserts into well-watered semiarid grasslands (Rosenberg et al, 2011(Rosenberg et al, , 2013Drake et al, 2013;Breeze et al, 2015Breeze et al, , 2016Jennings et al, 2015;Parton et al, 2015Parton et al, , 2018Groucutt et al, 2015bGroucutt et al, , 2018Roberts et al, 2018). These conditions facilitated the dispersal of a variety of novel taxa into Arabia, including hippos, elephants, large carnivores, and waterbirds (McClure, 1984;Thomas et al, 1998;Stimpson et al, 2016;Stewart et al, 2019aStewart et al, , 2019bGroucutt et al, 2018). Hominins, too, appear to have repeatedly occupied Arabia during these more humid intervals, as indicated by the archaeological record (e.g., Petraglia et al, 2011Petraglia et al, , 2012Groucutt and Petraglia, 2012;Shipton et al, 2014Shipton et al, , 2018Groucutt et al, 2015aGroucutt et al, , 2015bGroucutt et al, , 2018Scerri et al, 2015).…”

Fossil herbivore stable isotopes reveal middle Pleistocene hominin palaeoenvironment in ‘Green Arabia’

“…90 ka 20 , the Ti's al Ghadah evidence highlights that the focus on Pleistocene Homo expansions should not solely be limited to Eurasia, Africa and the Levant. The identification of Afrotropical, Saharo-Arabian and Palaearctic fauna [12][13][14][15] in association with hominin presence also highlights the possibility of middle, and perhaps also early, Pleistocene hominin migrations into the Arabian Peninsula from Africa and Eurasia. Future systematic survey and excavation will help to further constrain the chronology and nature of hominin dispersal into this part of the world.…”

“…In spite of its crucial geographical position at the interface of Africa and Eurasia, the Arabian Peninsula has remained remarkably absent from adaptive models of Pleistocene hominin expansions until relatively recently, owing to a lack of well-constrained archaeological and palaeoecological data. Climate modeling 10 , speleothem records 11 , palaeontological findings [12][13][14][15] , and geomorphological studies of palaeolake records 16,17 have been used to argue that at intervals in the past, notably during interglacials, the harsh, hyper-arid deserts that cover much of Arabia today were replaced by 'moister' and 'greener' conditions more hospitable to hominin occupation 18,19 . Furthermore, the find of an H. sapiens phalanx, in association with middle Palaeolithic stone tools, at the site of Al Wusta dated to ca.…”