State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Xiangshan, Beijing, People's Republic of China.
Published: November 2022
AI Article Synopsis
Article Abstract
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.
Shrews are among the most speciose of mammalian clades, but their evolutionary history is poorly understood. Their fossil record is fragmentary and even the anatomy of living groups is not well documented. Here, we incorporate the oldest, most complete fossil shrew yet known into the first phylogenetic analysis of the group to include molecular, morphological and temporal data.
Introduction Raoellidae are small artiodactyls retrieved from the middle Eocene of Asia (ca - 47 Ma) and closely related to stem Cetacea. Morphological observations of their endocranial structures allow for outlining some of the early steps of the evolutionary history of the cetacean brain. The external features of the brain and associated sinuses of Raoellidae are so far only documented by the virtual reconstruction of the endocast based on specimens of the species Indohyus indirae.
Pseudonotherobius kohlsi and Megalomus? coloradensis are newly identified species of lacewings from the early Eocene era, found in Colorado’s Green River Formation.
Pseudonotherobius is characterized by a specific crossvein in its forewings and a uniquely dilated hind wing, which sets it apart within its family.
The genus is tentatively placed within the Carobiinae subfamily, hinting at its similarity to a modern Australian lacewing species.
- A new beetle species, Rhantus villumi sp. nov., has been identified from a single specimen found in the Fur Formation of Denmark, dating back about 55.4 million years to the early Eocene, making it the oldest known member of its genus.
- The discovery aligns with phylogenetic studies and suggests that the presence of this temperate beetle in a typically warm environment indicates potential short-term cooling trends during that period.
- The newly identified species might have fed on mosquito larvae, which have also been found in the same fossil site; however, another Dytiscidae species was noted but remains unidentified due to preservation issues.
Furochrysa alisae gen et sp. nov. is described, and Stephenbrooksia multifurcata Willmann, 1993 and Danochrysa madseni Willmann, 1993 are re-described based on their holotypes and additional specimens from the early Eocene Fur Formation of Denmark.
