First direct evidence of conservative foraging ecology of early Gigantopithecus blacki (~2 Ma) in Guangxi, southern China

Abstract

Objectives Gigantopithecus blacki, the largest hominoid known, is one of the representative Pleistocene mammals in southern China and northern Southeast Asia. Here we investigate the feeding ecology of G. blacki in its core habitat (Guangxi, Southern China) during the early Early Pleistocene, which was the early period in its evolution. Materials and methods The stable isotopic (C, O) analysis of tooth enamel of the fauna associated with G. blacki (n = 58), including the largest number of G. blacki teeth (n = 12) to date from the Liucheng Gigantopithecus Cave (~2 Ma), Guangxi, China, is undertaken. Results The δ13C values of Liucheng fauna range from −12.9 to −19.0‰ with an average of −16.1 ± 1.3‰ (n = 58) and the δ18O values range from −4.3 to −9.6‰ with an average of −6.9 ± 1.2‰ (n = 58). The δ13C values of G. blacki range from −15.9‰ to −17.0‰ with an average of −16.5 ± 0.4‰ (n = 12), and the δ18O values vary from −5.9‰ to −7.5‰ with an average of −6.6 ± 0.5‰ (n = 12). Conclusions The isotopic data show Guangxi was characterized by closed C3 forest and humid climate in the early Early Pleistocene. Niche partitioning is found among G. blacki, Sinomastodon, Ailuropoda and Stegodon, the typical megafauna in South China in the early Early Pleistocene. This could be one of the important factors for them to co‐exist until the Middle Pleistocene. Smallest isotopic variations of G. blacki are found compared with those of contemporary animals, indicating a conservative foraging ecology i.e., limited foraging area and/or narrow dietary flexibility. Furthermore, the more confined foraging ecology of G. blacki is also seen in comparison with fossil and extant large‐bodied primates. However, the unique dietary pattern of G. blacki does not seem to have hindered its survival. The environment in Guangxi during the early Early Pleistocene offered the suitable conditions for G. blacki to become one of the typical species in the faunal assemblages.

Evolutionary ecology of Miocene hominoid primates in Southeast Asia

“…Data from published studies with a similar scope and objective were used as reference (Table SI 3) 12,17,[25][26][27][28][29][30][31][32][33][34][35][36][37] . These studies also analysed the carbonate fraction of dental enamel.…”

Estimates of absolute crown strength and bite force in the lower postcanine dentition of Gigantopithecus blacki

“…Carbon (C) and oxygen (O) isotopic analyses of tooth enamel have suggested that G. blacki foraged in densely forested habitat and consumed C3 plants exclusively (Zhao et al, 2011;Zhao and Zhang, 2013;Nelson, 2014;Qu et al, 2014;Bocherens et al, 2017;Jiang et al, 2021). In this paleoecological context, potential food sources would have been plentiful, leading to speculation about the foods possibly consumed by G. blacki, such as fruits (Woo, 1962;Ciochon et al, 1990;Han and Zhao, 2002;Wang, 2009), tough items (Daegling and Grine, 1994;Zhao and Zhang, 2013), and/or hard objects (Ciochon et al, 1990;Kupczik and Dean, 2008;Qu, 2014;Hu et al, 2022).…”

“…Attempts have been made to determine the dietary behavior of G. blacki through a variety of approaches, such as dentognathic morphology (e.g. enamel thickness, tooth root length, occlusal area, and mandibular corpus depth; Woo, 1962;Olejniczak et al, 2008a;Kupczik and Dean, 2008;Zhang and Zhao, 2013;Kono et al, 2014;Zhang and Harrison, 2017), stable isotope analysis (Nelson, 2014;Qu et al, 2014;Bocherens et al, 2017;Jiang et al, 2021;Hu et al, 2022), dental microwear (Daegling and Grine, 1994;Zhao and Zhang, 2013), incidence of dental caries (Han and Zhao, 2002;Wang, 2009), analysis of phytoliths (Ciochon et al, 1990), and analysis of starch grains (Qu, 2014). These studies provided indications-e.g.…”