Lasius peritulus

Introduction

Lasius peritulus is an extinct ant species known only from fossil specimens found in the Florissant Formation in Colorado, USA. These fossils date to approximately 34 million years ago during the Oligocene period. The species belongs to the Lasius niger-neoniger species group and represents about 25% of all ant fossils recovered from the Florissant deposits, making it one of the most common ant species in that formation . The fossils are preserved as impressions in shale, and while they show fine anatomical details, they cannot be used to establish living colonies. Queens from this species were small, toward the lower end of size variation in the genus, and showed the characteristic 'niger-type' mandible structure . This species has no living representatives and cannot be kept in captivity.