Pseudomyrmex saxulum

Introduction

Pseudomyrmex saxulum is an extinct ant species known from a single fossil queen discovered in the Middle Eocene Kishenehn Formation (about 44 million years old) in Montana, USA . This makes it the oldest known Pseudomyrmex species in the fossil record . The fossil is preserved in lateral compression, showing an overall dark brown body with lighter segmental margins and yellowish‑brown legs . The forewing length is 4.09 mm; full body length cannot be determined from the preserved specimen . Pseudomyrmex is a genus of slender, long‑legged ants typically found in tropical and subtropical regions, often nesting in plant cavities or wood, but the specific ecology of P. saxulum cannot be reconstructed from fossil evidence.