A new libelluloid family from the Eocene Green River Formation (Colorado, USA) (Odonata, Anisoptera) Author Zeiri, Asma Author Nel, Andre Author Garrouste, Romain text Zootaxa 2015 4032 3 290 296 journal article 10.11646/zootaxa.4032.3.4 dfc837d7-f020-4fa6-b4a4-e0fcbbb353ff 1175-5326 238343 EC2FE508-40E1-4464-868D-E2ED0BC56960 Genus Urolibellula gen. n. Type species. Urolibellula eocenica sp. n. Etymology . Named after the two genus names Urothemis and Libellula , for the position of this fossil as sister group of the Libellulidae , close to the Urothemistidae . Gender feminine. Diagnosis . As for the family.