A critical re-evaluation of bone surface modification models for inferring fossil hominin and carnivore interactions through a multivariate approach: Application to the FLK Zinj archaeofaunal assemblage (Olduvai Gorge, Tanzania)

Abstract

Article history: Available online xxx a b s t r a c t Over the past three decades, controversial interpretations of the behavioral meaning of bone surface modifications at FLK Zinj regarding primary or secondary access to carcasses by hominins have stemmed from the independent use of mark types (cut, percussion, and tooth marks) to evaluate opposing models. Such controversy has also been based on an over-reliance on tooth mark frequencies (mostly generated by non-hominin carnivores), which have been documented to be high when hyenids are primary bone modifiers, low when felids have primary access to carcasses, and high when suids feed primarily or secondarily on carcass parts. In addition, it has also been argued that the frequency of tooth marks on the FLK Zinj bones has been overidentified by some researchers, by mistaking tooth marks with biochemical marks created by plant roots. Some methodological approaches have hampered the use of cut marks to identify hominin behavior. Most of the reasons for purported equifinality of experimental scenarios are strictly methodological and are also caused by the separate rather than joint analysis of mark types. In the present work, for the first time cut marks, tooth marks, and percussion marks will be jointly analyzed, both experimentally and at FLK Zinj. Primary and secondary access to carcasses by hominins yields different frequency associations of all of these marks, which can be diagnostic of the type of access. Such mark-type relationships can only be detected when all mark types are analyzed simultaneously and not as separate sets. This multivariate approach provides a robust interpretation of primary access to carcasses by hominins at FLK Zinj.

Did Homo erectus kill a Pelorovis herd at BK (Olduvai Gorge)? A taphonomic study of BK5

“…Our taphonomic work has shown that Olduvai hominins had primary access to fleshed carcasses during the early Pleistocene (Domínguez-Rodrigo et al 2014d). Hominin bulk defleshing and demarrowing at FLK Zinj has also been supported recently by Parkinson et al (2015), who also reject that passive scavenging could have produced the taphonomic modifications documented in the Zinj faunal assemblage.…”

“…We have criticized this conclusion, arguing that when a comparative sample size is small, a forced bootstrap on it will not provide a more adequate analogical framework (Domínguez-Rodrigo et al 2014d;Domínguez-Rodrigo 2015). The assumption that for any sample size n the distribution for samples chosen at random is the sampling distribution inferred for the population can only be justified if n is really representative of the original population.…”

Blood, Bulbs, and Bunodonts: On Evolutionary Ecology and the Diets ofArdipithecus,Australopithecus, and EarlyHomo

“…Although meat often assumes the same exalted role as in “Man the Hunter,” these workers emphasize anatomical and cognitive (including technological) constraints on early hominid behavior that may have limited hunting ability, and instead point to a “scavenging niche” for early hominids (e.g., Blumenschine 1987). This hypothesis first gained widespread attention with taphonomic studies suggesting that hominids generally had access to carcasses following other consumers (e.g., Shipman and Philips-Conroy 1977; Shipman 1986), although these arguments created a verbal windstorm, and a monumental, oftentimes frustrating, literature has been generated by debates about whether certain archeological assemblages are best explained by hunting or by scavenging (e.g., FLK 22 Zinjanthropus ; Bunn and Kroll 1986; Binford 1988; Domínguez-Rodrigo 2002; Domínguez-Rodrigo and Barba 2006; Blumenschine et al 2012; Pante et al 2012; Domínguez-Rodrigo et al 2014). As reliable evidence of modified stone tools does not appear until 2.6 mya (Semaw et al 2003; claims from earlier dates are considered below), these taphonomic studies generally have little to say about Ardipithecus (sensu lato, Orrorin and Sahelanthropus are here considered likely congeners of Ardipithecus ) or its likely (but uncertain) descendant, Australopithecus .…”

“…Early access would suggest hunting or prompt “confrontational (power) scavenging” (chasing predators from their kills; Bunn and Ezzo 1993) and late access would suggest some form of passive scavenging. Four decades of concerted work at Olduvai Gorge (e.g., FLK Zinjanthropus , 1.8 mya) has scarcely helped the problem, as the same evidence is viewed in diametrically opposed fashion by different workers (early access emphasis reviewed in Domínguez-Rodrigo et al 2014; late access emphasis reviewed in Pante et al 2012). …”

The larger mammal palimpsest from TK (Thiongo Korongo), Bed II, Olduvai Gorge, Tanzania

“…The large and well preserved lithic and faunal assemblages from FLK (Frida Leakey Korongo), for instance, have generated a more-or-less continuous debate, from Leakey's (1971) pioneering work to the recent studies of Domínguez-Rodrigo et al (2014a). The collection from Level 22 (the Zinjanthropus Floor, or FLK-Zinj) has been presented as the earliest evidence for repeated hunting of small and medium-sized ungulates (Domínguez-Rodrigo and Barba, 2006;Domínguez-Rodrigo et al, 2007, 2014a, although models based on opportunistic scavenging have also been prevalent in the literature (Blumenschine and Selvaggio, 1988;Blumenschine, 1989Blumenschine, , 1991Blumenschine, , 1995Capaldo and Blumenschine, 1994;Capaldo, 1997;Pante et al, 2012).…”