The polar regions were much warmer than today, possibly as warm as the present-day Pacific Northwest of North America. Temperate forests reached the poles themselves, while rainy tropical climates reached 45° N. The greatest difference was in temperate latitudes; nevertheless, the climate at the tropics was probably similar to today's. In the Eocene, most of what is now Europe, the Mediterranean and south-west Asia was submerged under the Tethys Sea. These two continents were separated by the Turgai Strait (an epeiric sea). Due to high humidity and temperatures, most of the European continent was covered in vegetation. The region which today is Germany was in a volcanically active zone during the Eocene. It is thought that the Messel pit could have been the old location of a volcanic lake saturated with CO2. The lake would periodically release the gas it contained, creating a lethal cloud which would asphyxiate any animal in its path. This would explain the great number of non-aquatic species which have been found in the old lake-bed of the Messel pit. In the lush forests of this region, Leptictidium shared its habitat with animals such as Godinotia, Pholidocercus, Palaeotis or Propalaeotherium. There were also predators, the crocodilian Asiatosuchus, the hyaenodont Lesmesodon, and the Messel giant ant. Species The genus Leptictidium includes eight species. These include: Leptictidium auderiense Described by Heinz Tobien in 1962 based on a series of lower jaws from the Lutetian faunal stage. Tobien also uncovered a small skeleton he defined as a paratype of the species, but Storch and Lister proved in 1985 that, in fact, the skeleton did not even belong to the genus Leptictidium. It was the smallest species of all and was only sixty centimetres long. Several skeletons have been found at the Messel pit. Mathis remarks the exceptional development of the paraconid (or mesiobucal cusp) of the lower P4 premolar. Its premolars and molars were quite small in comparison to the dentition as a whole. The name of the species refers to the Roman settlement of Auderia. Leptictidium ginsburgi Described by Christian Mathis in 1989. Fossils have been found in the lagerstätte at Robiac, Le Bretou, Lavergne, La Bouffie, Les Clapiès, Malpérié and Perrière (France), in Upper Ludian strata. The mesostyle typical of the genus Leptictidium is not developed in this species. The species is dedicated to Léonard Ginsburg, French paleontologist and deputy director of the Muséum national d'histoire naturelle