Dental morphometrics and taxonomic reassessment of Late Miocene boselaphines (Tragoportax, Selenoportax, Pachyportax) from the Bhandar Bone Bed (Dhok Pathan Formation), Pakistan

Abstract

Background: The Siwalik Group of the Himalayan foreland basin preserves a rich record of Late Miocene mammalian evolution, with the Dhok Pathan Formation yielding abundant boselaphine bovids. Deciduous premolars, particularly DP3, are rarely documented in these taxa, limiting understanding of juvenile morphology and taxonomic variability. Objective: To describe and diagnose a rare isolated left DP3 from the Bhandar Bone Bed (Dhok Pathan Formation) and compare it metrically and morphologically to published material for taxonomic assignment. Methods: The specimen was surface-collected, mechanically and chemically cleaned, catalogued as USKT-PC 100923, measured using a digital Vernier caliper, and photographed in standardized views. Qualitative description focused on preservation, enamel texture, cusp development, styles, ribs, median valley, fossettes, and cingulum. Quantitative comparison used length, width, and published DP3 measurements. Results: USKT-PC 100923 is an unworn left DP3 (length 18.60 mm, width 12.00 mm) with shiny smooth enamel, prominent cusps, well-developed labial styles and ribs, deep fossettes, shallow median valley, and anterior cingulum. Metrics fall within the range of published Tragoportax DP3 specimens. Conclusion: The specimen is assigned to Tragoportax punjabicus (Pilgrim, 1910), representing a rare documentation of deciduous dentition that enhances morphological data for Siwalik boselaphines