Formica quadrata

Introduction

Formica quadrata is an extinct ant species known only from Baltic amber deposits dating to the late Eocene epoch, approximately 44-49 million years ago. The species was originally described by Friedrich Holl in 1829 based on a single specimen preserved in amber. The head is large but square-shaped with two pointed posterior ends, and the thorax bears two spines . Radchenko et al. (2021) have questioned whether this species actually belongs in the genus Formica, noting that based on the original description, it cannot be unambiguously assigned to any ant genus - it is considered incertae sedis (uncertain placement) within the Formicidae family .