age of fossil StW573 (‘Little Foot’): Reply to comments by Stratford et al. (2017)

Complexities of assessing palaeocave stratigraphy: reconstructing site formation of the ∼2.61 Ma Drimolen Makondo fossil site

“…This correlates with the extinction of Australopithecus and the first occurrence of Paranthropus robustus , Homo erectus and archaeology at DMQ, and perhaps also Swartkrans Member 1 Lower Bank ( Gibbon et al, 2014 ; Herries et al, 2020 ). Deposits dated to ≥ 2.61 Ma include the Australopithecus africanus bearing Makapangsat Limeworks Member 3 and the PCS deposits of the Buxton- Norlim Limeworks Pinnacles Type Site (Taung: 3.03–2.58 Ma) ( Herries & Adams, 2013 ), both of which are outside Gauteng Province in the CoH; the non-hominin bearing fossil site of Hoogland at 3.11–2.61 Ma ( Adams et al, 2010 ), and potentially the australopith bearing Sterkfontein Members 2 and 4 (between ∼3.7–2.2 Ma [ Pickering & Kramers, 2010 ; Herries & Shaw, 2011 ; Kramers & Dirks, 2017a ; Kramers & Dirks, 2017b ; Granger et al, 2015 ; Stratford et al, 2017 ] and 2.61 to 2.07 Ma respectively [ Pickering et al, 2019 ]). Therefore, with the exception of Sterkfontein and Malapa, DMK is a rare example of an australopithecine-aged site within the Gauteng Province in the CoH.…”

“…Palaeocave allogenic fill (inc. detrital silicates and often cemented by calcite) within the CoH is largely confined between ∼3 and ∼1 Ma ( Herries & Adams, 2013 ; Herries & Shaw, 2011 ; Herries et al, 2009 ; Herries et al, 2013 ; Gibbon et al, 2014 ; Pickering & Kramers, 2010 ; Pickering et al, 2019 ; Schwartz, Ziari & Trivedi, 1994 ). However, age ranges of ∼4 Ma ( Partridge et al, 2003 ) and ∼3.7 Ma ( Granger et al, 2015 ) have been presented for the StW573 australopithecine fossil from Sterkfontein, though the latter has been more recently contested (2.8–2.2 Ma; Kramers & Dirks, 2017a ; Kramers & Dirks, 2017b ; Stratford & Palmer, 2017 ). A more recent archaeological record can also be found from ∼300 ka with the discovery of hominin remains such as Homo naledi at Rising Star ( Dirks et al, 2017 ) and stone tools at sites such as Lincoln Cave at Sterkfontein ( Reynolds et al, 2003 ; Reynolds, Clarke & Kuman, 2007 ).…”