The Ants of the Genus Lasius (Hymenoptera, Formicidae) from Late Eocene European Ambers

Finds of the genus Lasius Fabricius in the Baltic, Bitterfeldian, Rovno, and Scandinavian Ambers (Late Eocene) are revised. Neotypes of L. pumilus Mayr, 1868 and L. punctulatus Mayr, 1868 are designated. A key to workers and gynes of Lasius species from the Late Eocene European ambers is compiled. All Lasius species from these ambers belong to the subgenus Lasius s. str. L. schiefferdeckeri Mayr, 1868 is one of most abundant ant species in the Late Eocene European ambers: it consists 15.2—19.5% of all ant specimens in Baltic Amber, 24.5% in Bitterfeldian Amber, 23.8% in Rovno Amber, and 23.6% in Scandinavian Amber of the examined collections. Based on the features of fossilization of this species, it is possible to assume that at least in part it constructed arboreal nests and made roads to aphids’ colonies. The list of nine ant species found in syninclusions with L. schiefferdeckeri is provided.Ревизованы находки рода Lasius Fabricius из балтийского, биттерфельдского, ровенского и скандинавского янтарей (поздний эоцен). Обозначены неотипы L. pumilus Mayr, 1868 и L. punctulatus Mayr, 1868. Приведена таблица для определения видов Lasius позднеэоценовых янтарей Европы по рабочим и самкам. Все виды из позднеэоценовых янтарей Европы относятся к подроду Lasius s. str. Одним из самых массовых видов муравьев янтарей является L. schiefferdeckeri Mayr, 1868. В изученных репрезентативных коллекциях балтийского янтаря его особи составляли 15,2—19,5%, биттерфельдского – 24,5%, ровенского – 23,8% и скандинавского – 23,6%. Основываясь на особенностях захоронения этого вида, можно предполагать, что его гнезда, по крайней мере, частично располагались на деревьях и что муравьи делали на стволах дороги к колониям тлей. Приведен список из 9 видов муравьев, обнаруженных в сининклюзах с L. schiefferdeckeri

Yantaromyrmex gen. n. – a new ant genus (Hymenoptera: Formicidae) from Late Eocene ambers of Europe

A new genus of ants from the Late Eocene ambers of Europe is described. Yantaromyrmex gen. n. includes five species, three of them have been previously described in the genera Hypoclinea Mayr, 1855 (Y. constrictus (Mayr, 1868), comb. n., and Y. geinitzi (Mayr, 1868), comb. n.) and Iridomyrmex Mayr, 1862 (Y. samlandicus (Wheeler, 1915), comb. n.), and were transferred to the genus Anonychomyrma Donisthorpe, 1947 in the recent revision of the genus Iridomyrmex [Heterick, Shattuck, 2011]. Two new species, Y. intermedius sp. n. and Y. mayrianum sp. n., are described. Species of the new genus combine plesiomorphic characters of both Iridomyrmex and Anonychomyrma, but cannot be included to any of these genera. Probably the genus Yantaromyrmex gen. n. is ancestral to both of these genera and for the tribe Iridomyrmecini sensu Dubovikoff [2005], as a whole. A key to species of the genus Yantaromyrmex gen. n. based on workers is give

New middle Eocene formicid species from Germany and the evolution of weaver ants

Two new species of weaver ant are described from the Eocene of Germany. Males and gynes of Oecophylla longiceps Dlussky sp. nov. are found in the middle Eocene (about 47 Ma) of Grube Messel, Germany. Males, gynes and two workers of O. eckfeldiana Dlussky sp. nov. are recorded from the middle Eocene (about 43 Ma) of Eckfeld maar, Germany. The two new species are among the oldest records of the extant genus Oecophylla. First adaptations for moving in the forest canopy are present in the workers of O. eckfeldiana. Even more specialized adaptations for arboreal life are found in the workers of O. brischkei from Baltic amber. The coexistence of two species in Baltic amber and in the Bembridge marls suggests that in these cases different ecological niches were realised by sympatric species. Comparisons of the queens from different fossil and extant species indicate morphological trends, partly connected with increasing fertility. Most likely Oecophylla originated in the early Paleogene in the Palaearctic realm, radiating strongly during the climatic changes of the Eocene–Oligocene transition