Surprisingly, after the Early Cretaceous taxonomic diversity recorded in Europe, which probably is largely an artifact of inadequate taxonomy and inflation of taxa, multituberculate mammals became extremely scarce in the Late Cretaceous in this continent, being reported exclusively from the uppermost Cretaceous continental deposits of the so-called “Haţeg Island” in Transylvania, Romania. Such mammals have been documented from the Haţeg and Rusca Montană sedimentary basins, as well as from the southwestern area of the Transylvanian Basin. All these records belong to the endemic family Kogaionidae. The present paper reports additional data related to the smallest Cretaceous kogaionid, Barbatodon oardaensis Codrea, Solomon, Venczel & Smith, 2014 based on a series of new isolated teeth recovered mainly from the type locality, Oarda de Jos (Oarda A). Furthermore, the fossil locali-ties Oarda B and Vălioara are other new occurrences for the species. Based on this new material, the intraspecific variability of B. oardaensis is confirmed and its presence is attested in the three basins. Details related to the diversity of the “Haţeg Island” kogaionids are also provided.
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Previous palaeoenvironmental reconstructions have implied that East Asia was dominated by a zonal climate pattern during the Eocene, with an almost latitudinal arid/semiarid band at ~ 30° N. However, this long-standing model has recently been challenged by growing body of multidisciplinary evidence. Some studies indicated that central China was characterized by climatic fluctuations between humid and drier conditions during the Early Eocene, akin to the present East Asian monsoon (EAM) regime. Using palynological assemblages in the Tantou Basin, central China, we quantitatively reconstructed climate changes from the Late Palaeocene to Early Eocene to better understand climate change in central China. Palynological assemblages revealed that the coniferous and broad-leaved mixed forest in this area received no less than 800 mm of annual precipitation and experienced a climate change from warm and wet to relatively cool and dry. According to palaeoclimate curves, a sudden climate change occurred in the Early Eocene, with the mean annual temperature and precipitation decreasing by 5.1 °C and 214.8 mm, respectively, and the climate became very similar to the present climate, which is controlled by the monsoon. Therefore, this significant climate change during the Early Eocene may signal the emergence of the EAM in East Asia.
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