Fig 1.
Chagyrskaya Cave, southwestern Siberia, Russia.
a. cave location map (created in ArcGIS software, using open data from https://www.usgs.gov/products/maps accessed on December 15, 2021); b. stratigraphic sequence with Chagyrskaya 64 molar discovery location indicated in orange; c. general view of the cave; d. discovery location of the Chagyrskaya 64 molar in situ in Layer 6c/2.
Fig 2.
Chagyrskaya 64 molar tooth and its macro-features.
1 General view of the tooth in five projections; a–c. Macro-photographs of the crown’s occlusal surface features: a. superior view of the concavity; b. stepped groove on the concavity’s wall; c. cross-sectional profile of the groove.
Fig 3.
Discovery location of the Chagyrskaya 64 molar.
Stratigraphic sequence (created in CorelDraw based on excavation data).
Fig 4.
Retouched points (1, 4) and perforators (2, 3, 5) from Layer 6c/2 in Chagyrskaya Cave.
Fig 5.
Comparison of Chagyrskaya 64 (1) and #1564 lower molar from Chagyrskaya Сave (2) dentine density distribution.
Chagyrskaya 64 exhibits heterogeneous structure of dentine, with demineralized foci, marked by dark gray color and orange lines. #1564 shows homogenous dentine, without signs of demineralization. a, b, c, d. most intensively demineralized dentin areas. Light pink color of the Chagyrskaya 64 roots indicates hypercementosis.
Fig 6.
Experimental tools fabricated from local jasperoid raw material.
Dotted lines show the active parts of the tools. a–c. perforators.
Fig 7.
Arrow indicates a toothpick groove.
Fig 8.
Chagyrskaya 64, toothpicking groove and linear traces on the distal interproximal surface.
1 macro-photo of the groove; a–c. macro- and micro-photos of linear striations.
Fig 9.
Chagyrskaya 64, linear traces of toothpicking on the mesial approximal surface.
Fig 10.
Chagyrskaya 64, unmodified crown sections with characteristic polish from ante-mortem wear. a, b. macro-photos; c, d. micro-photos.
Fig 11.
Chagyrskaya 64, three recesses in the occlusal surface of the crown (macro-photo).
Fig 12.
Results of CT-scan of the Chagyrskaya 64 molar.
Morphology of the concavity is shown in five projections, from left to right: mesial (1) distal (2, 3), disto-buccal (4), buccal (5).
Fig 13.
Chagyrskaya 64 ante-mortem modification of the concavity. a, b. smoothing and polish on the walls; c, d. polish on the edge.
Fig 14.
Results of Raman spectroscopic analyses of the tooth surface.
Analysis points at the top; Raman spectra of the tooth and experimental samples at the bottom.
Fig 15.
Chagyrskaya 64, microscopic traces indicative of rotation technique on the interior walls of the concavity.
Horizontally oriented linear traces run parallel to the concavity edges at two distinct locations (a–b and c–d). a–d. micro-photos.
Fig 16.
Comparison of the linear traces forming concavities on Chagyrskaya 64 and experimental tooth #3.
1, 2 top views; a, d. macro-photos of grooves along the edges of the concavity walls; b, e. profile measurement points; c, f. profile measurements.
Fig 17.
Microscopic evidence of concavity formation through drilling/rotating.
Horizontal linear striations aligned parallel to the concavity’s edges are visible on the concavity walls. Comparative illustrations of these linear striations. a. Chagyrskaya 64 Neanderthal molar; b. experimental modern H. sapiens specimen #3.
Fig 18.
Occlusal, distal and mesial views.
Fig 19.
Chagyrskaya 18 micro-CT image.
Carious lesion on the occlusal surface of the molar. Transverse section. The arrow points to the area of damaged enamel.