Formica ribbeckei

Introduction

Formica ribbeckei is an extinct ant species known only from fossil specimens preserved in late Eocene Rovno amber from Ukraine, dating to approximately 33.9-37.8 million years ago. Workers measured 4.7-6.5 mm in body length, making them comparable in size to many modern Formica species. The species was described in 2021 based on four well-preserved worker specimens found in amber deposits in the Zhitomir and Rovno regions of Ukraine . This ant belongs to the Formicinae subfamily and the Formicini tribe, the same group that includes many common wood ants alive today. The species most closely resembles the extinct Formica flori but can be distinguished by its 5-segmented maxillary palps and shorter first funicular segment .