Eulithomyrmex

Eulithomyrmex Temporal range: Priabonian PreЄ Є O S D C P T J K Pg N ↓
E. rugosus holotype
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Order:	Hymenoptera
Family:	Formicidae
Subfamily:	Agroecomyrmecinae
Tribe:	Agroecomyrmecini
Genus:	†Eulithomyrmex Carpenter, 1935
Species
E. rugosus E. striatus
Synonyms
Lithomyrmex Carpenter, 1930

Eulithomyrmex is an extinct genus of ant in the formicid subfamily Agroecomyrmecinae. The genus contains two described species, Eulithomyrmex rugosus and Eulithomyrmex striatus. Eulithomyrmex is known from a group of Late Eocene fossils which were found in North America.

When described the genus Eulithomyrmex was known from over forty separate fossils preserved as impressions in fine shales of the Florissant formation in Colorado. The formation is composed of successive lake deposits which have preserved a diverse assemblage of insects. The insects and plants suggest a climate similar to modern Southeastern North America, with a number of taxa represented that are now found in the subtropics to tropics and confined to the old world. When Eulithomyrmex was described, the Florissant formation was considered to be Miocene in age, based on the flora and fauna preserved. Successive research and fossil descriptions moved the age older and by 1985 the formation had been reassigned to an Oligocene age. Further refinement of the formation's age using radiometric dating of sanidine crystals has resulted in an age of 34 million years old. This places the formation in the Eocene Priabonian stage.

At the time of description the holotype and three paratypes of E. rugosus plus the holotype and single paratype of E. striatus were deposited in the Museum of Comparative Zoology paleontology collections at Harvard University. One additional paratype specimen, number 17,019a, was part of the collections of the University of Colorado. The fossils were first studied by paleoentomologist Frank M. Carpenter of the Museum of Comparative Zoology. His 1930 type description of the new species was published in the Bulletin of the Museum of Comparative Zoology. Carpenter described the genus under the name Lithomyrmex, with the two species respectively as Lithomyrmex rugosus and Lithomyrmex striatus. Carpenter designated L. rugosus ad the type species for the genus. At the time of Carpenters description, the generic name Lithomyrmex had already been used in 1929 for a modern ant species Lithomyrmex glauerti. As a result, Carpenter moved the two species to the new genus Eulithomyrmex.