Abstract:

Gigantopithecus blacki, the largest extinct species within the family Hominidae, provides significant insights into the survival adaptations and extinction of primates. This study focuses on the plant-based dietary evidence of G. blacki from the Gigantopithecus Cave site in Liucheng, Guangxi. Using micro-nano spectral CT analysis, we systematically tested the composition of dental calculus samples attached to the teeth of the only three currently discovered G. blacki mandibles, extracting and analyzing the plant residues within these samples. The results show that the plant microfossils identified in the dental calculus include: starch granules from Poaceae grass seeds, fruits of woody plants, and plant roots and stems; Elongate echinate phytoliths; and tracheary elements from Water Hemlock or fern plants. Additionally, the samples contained ladder-like perforation plates from woody plant stems and reticulate vessels from the phloem of Lardizabalaceae plants. These findings indicate that the diet of G. blacki was highly diverse, covering multiple ecological niches of C₃ plants and providing new evidence for its bamboo consumption behavior. This also suggests its selection of ancient relict plant groups, offering new perspectives on the ecological relationship between large primates and ancient plant communities.

In summary, although the G. blacki specimens from the Liucheng Gigantopithecus Cave site date back approximately 1.2 to 0.9 million years, dental calculus on some of the teeth retained sufficient plant residue information to support further dietary reconstruction. This study combines micro-nano spectral CT and plant residue extraction techniques, enabling rapid compositional assessment of calculus samples, thus providing a novel approach for future research on fossilized dental calculus samples that are difficult to distinguish visually. Future research should expand along both temporal and spatial dimensions: temporally, by analyzing G. blacki dental fossil samples from different geological periods, comparing the differences in plant community composition across these periods, and exploring whether its diet adapted to changes in paleoclimate and paleovegetation, thereby providing dietary evidence for understanding the evolutionary dynamics of G. blacki; spatially, considering the current distribution of G. blacki fossils across Guangxi, Hubei, Chongqing, Guizhou, and Hainan, future comparative studies of regional samples could analyze whether geographical isolation led to regional dietary differentiation, investigate the impact of different regional paleoenvironments on its diet, and refine the study of G. blacki’s ecological distribution and adaptation patterns. This would provide a more comprehensive ecological perspective for exploring the diet and extinction of Gigantopithecus blacki.

Key words: Gigantopithecus blacki, starch granules, phytoliths, plant tracheary elements, diet