Anatomical Evidence of Habitual Squatting in Homo erectus from Java

Ashwin Prayudi1,2*, Anggraeni1, Mahirta1, Sofwan Noerwidi3, Trilusiana Rahmawati2, Rusyad Adi Suriyanto2, and Janatin Hastuti2 

This study presents a morphological analysis of a squatting facet identified on the distal tibia of Ngandong 10 (Tibia B), a specimen recovered from Middle to Late Pleistocene Bengawan Solo River deposits in Central Java. While the biological sex of the individual remains indeterminate, the dimensions of the element confirm its attribution to an adult Homo erectus. The facet is situated on the lateral aspect of the anterior margin of the distal epiphysis, measuring approximately 1.5 cm by 0.7 cm. Although the specimen exhibits degradation consistent with fluvial transport and sedimentary abrasion, the peripheral margins of the facet remain sufficiently intact for diagnostic assessment. Comparative observations were conducted against Homo sapiens assemblages from Java and Bali, revealing that the morphology and anatomical placement of these facets are consistent across both species. The habitual use of the squatting position is a long-standing inquiry in paleoanthropology, as it provides indirect evidence for ground-based behavioral patterns. The presence of these markers in Ngandong remains suggests that Homo erectus engaged in prolonged sedentary activities, such as lithic reduction or food processing, consistent with the bioarchaeological record of later Asian Homo sapiens populations.