A Middle Eocene lowland humid subtropical “Shangri-La” ecosystem in central Tibet

Menispermaceae are a pantropical and temperate family with an extensive fossil record during the Paleogene period, especially in North America and Europe, but with much less evidence from Asia. The latest fossil evidence indicates a succession of tropical to subtropical flora on the central Tibetan Plateau during the Paleogene. However, the biogeographic histories of these floras are still unresolved. Here, we report on endocarps and leaves of Menispermaceae from the Middle Eocene of Jianglang village, Bangor County, central Tibetan Plateau. The endocarps belong to two genera:Stephania, which is characterized by a horseshoe‐shaped endocarp and with one lateral crest ornamented by spiny to rectangular ribs, and a condyle area; andCissampelos(s.l.), which has two characteristic lateral ridges and a conspicuous external condyle. Associated leaves belong to the genusMenispermites, and are characterized by actinodromous primary venation, brochidodromous secondary veins, entire margins, and the presence of marginal secondary veins. The biogeographic history of Menispermaceae is complex, but evidence from these new fossils indicates an early diversification of the group in Asia, probably in response to the warming climate during the Eocene. The Jianglang flora appears to be part of a boreotropical flora, connecting Asia with North American and European floras during the Middle Eocene. The modern distribution of menispermaceous taxa found in Jianglang, as well as other families represented in the Jianglang flora, show that a tropical to subtropical climate occurred during the Eocene in central Tibet.

Late Eocene Rodent radiations: North America, Europe and Asia

The taxonomy, chronostratigraphy and paleobiogeography of glyptosaurine lizards (Glyptosaurinae, Anguidae)

Although the Indo-Pacific is considered to be the greatest marine biodiversity hotspot in the world, the origin and evolution of Indo-Pacific biodiversity is still largely understudied and unknown. Thus, the primary goal of this project is to increase our understanding of the development of Central Indo-Pacific marine biodiversity by investigating coral reef evolution during the origin of the Indo-Pacific marine biodiversity hotspot (Late Eocene – Early Miocene). Here I focus on (1) evolution of coral reef habitats from carbonate platforms; (2) systematic description of new fossil corals and detailed records of their temporal and spatial distribution; and (3) analysis of temporal changes in coral taxonomic and functional diversity. Evolution of coral reef habitats in the Central Indo-Pacific was investigated by examining Eocene-Miocene shallow-water carbonate platforms from Sarawak, Malaysia.In order to reconstruct paleoenvironments and detect marine carbonate producers during the late Middle Eocene to the Early Miocene, I used an integrative approach combining point counting data (counts of constituent types in limestone thin section) and geologic field data (measured and described stratigraphic sections). During the studied time interval, the dominant carbonate producer changed from large benthic foraminifera to corals. Although coral-associated environments began increasing in abundance during the Oligocene, paleoenvironments dominated by foraminifera persisted but significantly declined in abundance. This increase in coral abundance led to an increase in habitat diversity as well as a change in carbonate platform type from ramp to isolated platforms. Such changes in carbonate platform morphology were likely driven by local tectonic forces. The evaluation of spatial and temporal patterns in the shallow-water carbonate platforms provides context for understanding the development of coral reef habitats during the origination of the Indo-Pacific marine biodiversity hotspot. Systematic description of new fossil corals was based on a new fossil collection of the Central Indo-Pacific. The fossil corals were collected from several geological formations in Sarawak (Malaysia), Cebu and Negros (the Philippines). In Sarawak the Melinau (Early Miocene - Aquitanian) and the Subis (Early Miocene - Aquitanian) Limestones were studied, in Negros the Teankalan/Binaguiohan Limestone (Early Miocene - Aquitanian), and in Cebu the Calagasan Formation (late Oligocene – middle Chattian) and the Butong Limestone Formation (late Oligocene – late Chattian). Taxonomic analysis of the new fossil coral collection resulted in descriptions of 83 morphospecies belonging to 37 genera. The new collection expanded the temporal ranges of 28 coral genera. Taxonomic descriptions and detailed records of the temporal and spatial distributions of the new fossil corals are fundamental for any study of coral taxonomy, diversity and biogeography through time.Analysis of temporal changes in coral taxonomic and functional diversity was based on the new fossil collection from the Central Indo-Pacific (described in Chapter 3) and an extensive literature search. A total of 122 genera were included in the analysis. After the confidence intervals of taxa’s first- and last-appearance datum (FAD and LAD) were calculated, coral diversity was estimated using two methods: mean standing diversity and Chao2 index. Additionally, functional diversity was estimated for all coral genera by evaluating five morphological traits (colony attachment, corallum type, colony growth form, corallite arrangement and corallite size). Both taxonomic and functional diversities show the strongest increase from the Chattian (~28.4 – 23 ma) to the Burdigalian (~20.4 – 15.97 ma). Observed increase in habitat diversity from the Late Eocene to the Early Miocene coincides with increases in both taxonomic and functional diversity of reef-building corals. Hence, the origin of the Indo-Pacific biodiversity hotspot in the Chattian (~ 28 ma ago) may be a consequence of an increase in habitat diversity driven by local tectonic events. These results provide a baseline for detecting environmental drivers for the evolution of marine biodiversity. This new knowledge about previous biodiversity changes may provide insight about future changes in biodiversity caused by present, and anticipated, environmental fluctuations.

The Paleogene primate fossil record is reviewed following higher systematic categories. Among Strepsirhini, Adapiformes underwent Eocene radiations in North America (Notharctinae) and Europe (Cercamoniinae, Adapinae). Several occasional occurrences due to dispersals are found in North America, Europe, and Africa. Asia reveals a limited diversification (Sivaladapidae) and isolated occurrences indicating a central yet poorly understood role. In Africa the origin of living Lemuriformes is documented in the Late Eocene; odd stem lemuriforms occur earlier. The Eocene florescence of Omomyiformes is documented in North America (Anaptomorphinae, Omomyinae) and in Europe (Microchoeridae). Isolated occurrences, including the stem genus Teilhardina, are known in Asia. Two genera of Tarsiidae, known in the Middle Eocene of Asia, lead to a possible character-based definition of Haplorhini. The Asiatic Eosimiidae may belong in this group, and Archicebus may possibly lie on its stem. The Eocene South Asiatic Amphipithecidae are specialized hard-object feeders whose affinities remain enigmatic. Character-based Anthropoidea, or Simiiformes, are documented in the Late Eocene and Oligocene of Africa (Parapithecidae, Proteopithecidae, Oligopithecidae, Propliopithecidae). Toward the end of the Oligocene, the first African proconsuloids and the first South American platyrrhines appear. Anthropoidean origins are still a field of debate and discovery, with unconvincing Asiatic stem simians and a possible role for African Afrotarsiidae. The fossil record is extremely uneven, going from richly documented lineages in the Eocene of North America, to well-delineated radiations in the Eocene of North America and Europe and the Eocene–Oligocene of Africa, to more dispersed occurrences and enormous gaps during the early periods in Africa and Asia. The latters explain persisting controversies. Many aspects of primate evolution are documented over almost 20 million years, including locomotion, diet, vision and other sensory capacities, brain evolution, and one aspect of social structure via sexual dimorphism. The best records allow researchers to approach specific lineages, evolutionary modes, and analysis of faunistic changes. 1138 M. Godinot

Artiodactyls diversified during the Eocene and Oligocene in North America and Europe after their first Holarctic appearance at the beginning of the Eocene. However, the relationships among early artiodactyls, European endemic forms, and later derived suiforms, tylopods, and ruminants remain unclear. Early artiodactyls are relatively rare in Asia compared to those known from North America and Europe; thus, investigation of Eocene artiodactyls from Asia is important to resolve these issues. Here we report two new genera and three new species of small early artiodactyls from middle Eocene deposits of the Erlian Basin, Inner Mongolia, China. The new materials represent a morphologically gradational series from Asian Land Mammal Ages Irdinmanhan to Sharamurunian, characterized by a trend towards bilophodonty in the lower molars. Morphologic and phylogenetic analyses suggest that these new taxa have a close relationship with the enigmatic European Tapirulus, which currently consists of five species that range from the middle Eocene to the early Oligocene. The close relationship between the Erlian specimens and Tapirulus suggests possible faunal exchanges between Europe and Asia during the middle Eocene, a view that has been supported by other mammalian groups across the two continents. The evolution of bilophodonty in Tapirulidae and Raoellidae is probably attributable to convergence.

Background: Sensitization to weed pollen allergens at the molecular level is not fully understood. We studied IgE reactivity to the major mugwort allergen Art v 1 in relation to allergens from other weed pollen and cross-reactive components in mugwort-sensitized subjects. Methods: Art v 1 and Amb a 1 were affinity purified and coupled to experimental ImmunoCAP® tests. Samples from North Europe (n = 50), South Europe (n = 19) and North America (n = 41) were analyzed for IgE against mugwort pollen, weed allergen components, pan-allergens and cross-reactive carbohydrate determinants (CCDs). Results: The prevalence of IgE reactivity (>0.35 kU_A/l) to Art v 1 was significantly higher in samples from North Europe than in those from North America. IgE to Amb a 1 was more common in North America than in North and South Europe, while IgE to Par j 2 was common in South Europe, less common in North America, and absent in North Europe. IgE to Art v 3 in mugwort-allergic patients was more common in North Europe than in South Europe and North America, while IgE to Sal k 1 was similar between the areas. Subjects with an Art v 1/mugwort-specific IgE ratio <0.5 had more often IgE to Amb a 1, profilin, polcalcin and CCDs than subjects with a ratio >0.5. Conclusions: Mugwort-sensitized subjects have different IgE reactivity profiles to weed allergens, reflecting their exposure to various pollens. Subjects with a low ratio between the IgE levels to Art v 1 and mugwort have a diverse IgE reactivity profile, indicating a role for cross-reactive allergens in their mugwort sensitization.

Temperate woody plants in the Northern Hemisphere have long been known to exhibit high species richness in East Asia and North America and significantly lower diversity in Europe, but the causes of this pattern remain debated. Here, we quantify the roles of dispersal, niche evolution, and extinction in shaping the geographic diversity of the temperate woody plant family Juglandaceae (walnuts and their relatives). Integrating evidence from molecular, morphological, fossil, and (paleo)environmental data, we find strong support for a Boreotropical origin of the family with contrasting evolutionary trajectories between the temperate subfamily Juglandoideae and the tropical subfamily Engelhardioideae. Juglandoideae rapidly evolved frost tolerance when the global climate shifted to ice-house conditions from the Oligocene, with diversification at high latitudes especially in Europe and Asia during the Miocene. Subsequent range contraction at high latitudes and high levels of extinction in Europe driven by global cooling led to the current regional disparity in species diversity. Engelhardioideae showed temperature conservatism while adapting to increased humidity, tracking tropical climates to low latitudes since the middle Eocene with comparatively little diversification, perhaps due to high competition in the tropical zone. The biogeographic history of Juglandaceae shows that the North Atlantic land bridge and Europe played more critical roles than previously thought in linking the floras of East Asia and North America, and showcases the complex interplay among climate change, niche evolution, dispersal, and extinction that shaped the modern disjunct pattern of species richness in temperate woody plants. [Boreotropical origin; climatic niche evolution; disjunct distribution; dispersal; diversity anomaly; extinction; Juglandaceae.]

Quantitative reconstruction of Middle and Late Eocene paleoclimate based on palynological records from the Huadian Basin, northeastern China: Evidence for monsoonal influence on oil shale formation

This study examined adapoid and omomyoid euprimate dietary and body size diversity from the Eocene of North America and Europe. Estimates of body weights and shearing quotients calculated from lower molars were plotted on a coordinate graph as a representation of dietary niche space (dietary ecospace) occupied by extinct species. By computing the areas, average intertaxon distances, and average distances from the centroid of the resulting polygons, comparisons of Eocene euprimate dietary and body size diversity were made. Results indicate that euprimate dietary niche space expanded significantly in North America from the Early to Middle Eocene, and at all times during the Early and Middle Eocene, the niche space occupied by North American euprimates exceeded that of corresponding European euprimates. These results confirm that fossil euprimate diversity, as measured by diet and body size, significantly differed across biogeographic areas. There are many possible explanations as to why North American euprimates were significantly more diverse in terms of diet and body size than their European counterparts. The explanation advocated here as most responsible for the increased diversity during the Early and Middle Eocene relates to the existence and increased sampling of more ecologically diverse environments, such as basin margins in the western interior of North America. These diverse environments could have promoted biological processes that led to the generation of increased diversity in North America compared to the isolated island refugia of Western Europe during this time.

The time and mechanism of crustal thickening and initial surface uplift of the Tibetan Plateau remain highly controversial. Here we report on zircon U‐Pb age, and mineral, element, and Sr‐Nd isotope composition data for Eocene adakitic porphyries in the Laorite Co area of central‐northern Qiangtang Block, central Tibet. Laser ablation‐inductively coupled plasma‐mass spectrometry zircon U‐Pb age dating shows that the porphyries were generated at 42–41 Ma. All samples display adakitic geochemical characteristics, such as high SiO2 and Al2O3, and low Y and Yb contents, and high Sr/Y and La/Yb ratios with positive Sr and negligible Eu anomalies and Nb‐Ta depletion. They also have low magnesium number (Mg #) (16–45) and high K2O (4.0–4.6 wt %) values, as well as high (87Sr/86Sr)i (0.7076–0.7080) and low εNd(t) (−5.9 to −4.4) values. These adakitic rocks were most probably generated by partial melting of thickened lower crust in the stability field of garnet, amphibole, and rutile but with relatively minor plagioclase. Moreover, such a crustal thickening process beneath this block likely occurred no later than the middle Eocene and was most probably caused by the southward subduction of the Songpan‐Ganzi Block in the early Cenozoic. In addition, the occurrences of exposed adakitic porphyries unambiguously indicate that exhumation process occurred after their formation. Thus, these ~42 Ma adakitic porphyries indicate the occurrence of significant exhumation since 42 Ma. Integrated with the thermochronological and paleoelevation data, we suggest that the initial surface uplift of the Qiangtang Block, triggered by crustal thickening, was underway by the middle Eocene (~42 Ma).

Amynodontidae is a family of Rhinocerotoidea (Mammalia, Perissodactyla) known from the late Early Eocene to the latest Oligocene, in North America and Eurasia. European Amynodontidae are very rare, and all remains belong almost exclusively to a single post—Grande Coupure genus from the Oligocene, Cadurcotherium. The “Grande Coupure” defines an extinctions and dispersal-generated originations event in Europe that is nearly contemporaneous with the Eocene-Oligocene transition. Perissodactyls are one of the major groups affected by this event: Palaeotheriidae went almost extinct during this crisis, whereas Rhinocerotidae appeared for the first time in Europe. Study of fossiliferous Eastern-European localities from this age is crucial for the understanding of this crisis. We report here three new localities of Amynodontidae in Eastern Europe. Two of them are dated from the Eocene (Morlaca, Romania; Dorog, Hungary), whereas the other is either Late Eocene or Early Oligocene (Dobârca, Romania). The skull from this latter locality belongs unexpectedly to the same individual as a previously described mandible attributed to “Cadurcodon” zimborensis. As a result, this specimen can be allocated to its proper locality, Dobârca, and is assigned to a new genus, Sellamynodon gen. nov. It is characterised by an extraordinary growth of the nuchal crest, a unique character among amynodontids. Along with this remarkable material from Dobârca, two specimens from another Romanian locality, Morlaca, have been recently discovered and are dated from the Late Eocene. They belong, as well as new material from Dorog (Middle Eocene, Hungary), to the genus Amynodontopsis, also found in North America. The new Hungarian material represents the earliest occurrence of Amynodontidae in Europe. New phylogenetic hypotheses of Rhinocerotoidea are proposed, including the new material presented here, and show that Amynodontidae may be closer to the polyphyletic family ʽHyracodontidaeʼ than to Rhinocerotidae. Amynodontidae, with their deep preorbital fossa and extremely reduced premolars, display in fact a very derived condition, compared to rhinocerotids.

The relationships of nitrogen biogeochemistry are reviewed, focusing on forested watersheds in North America, Europe and Japan. Changes in both local and global nitrogen cycles that affect the structure and function of ecosystems are described. Within northeastern United States and Europe, atmospheric deposition thresholds of ~8 and ~10 kg N ha−1 year−1, respectively, result in enhanced mobilization of nitrate. High nitrate concentrations and drainage water loss rates up to 22 kg N ha−1 year−1 have also been found near Tokyo. Although atmospheric deposition may explain a substantial portion of the spatial pattern of nitrate in surface waters, other factors also play major roles in affecting the spatial patterns of nitrogen biogeochemistry. Calcium availability influences the composition of the vegetation and the biogeochemistry of nitrogen. The abundance of sugar maple is directly linked to soil organic matter characteristics and high rates of nitrogen mineralization and nitrification. Seasonal patterns of nitrate concentration and drainage water losses are closely coupled with differences in seasonal temperature and hydrological regimes. Snow-dominated forested catchments have highest nitrate losses during snowmelt. Watersheds in the main island of Japan (Honshu) with high summer temperatures and precipitation inputs have greatest losses of nitrate occur during the late summer. Understanding future changes in nitrate concentrations in surface waters will require an integrated approach that will evaluate concomitantly the influence of both biotic and biotic factors on nitrogen biogeochemistry.

The oldest anthropoid primates in SE Asia: Evidence from LA-ICP-MS U–Pb zircon age in the Late Middle Eocene Pondaung Formation, Myanmar

Podocarpium (Fabaceae) from the late Eocene of central Tibetan Plateau and its biogeographic implication