The Implications of the Pollen of the Norian/Rhaetian Triassic New Mexico

Palynology of the upper Chinle Formation in northern New Mexico, U.S.A.: Implications for biostratigraphy and terrestrial ecosystem change during the Late Triassic (Norian–Rhaetian)

Authors:

Lindström et al

Abstract:

A new densely sampled palynological record from the vertebrate-bearing upper Chinle Formation at Ghost Ranch in the Chama Basin of northwestern New Mexico provides insights into the biostratigraphy and terrestrial ecosystem changes during the Late Triassic of northwestern Pangaea. Spore-pollen assemblages from the Poleo Sandstone, Petrified Forest, and 'siltstone' members are dominated by pollen of corystospermous seed ferns (Alisporites) and voltziacean conifers (Enzonalasporites, Patinasporites). Other abundant taxa include Klausipollenites gouldii and the enigmatic fused tetrad Froelichsporites traversei, whereas spores of ferns and fern allies are generally rare. The assemblages are correlated with Zone III Chinle palynofloras of previous authors. The lower assemblages contain rare occurrences of typical Zone II taxa, namely Cycadopites stonei, Equisetosporites chinleanus and Lagenella martini, that may either be reworked or represent relictual floral elements. Marked step-wise losses of species richness, along with only minor appearances of new taxa, led to a total 50% drop in range-through diversity during the late Norian of the Chama Basin. Correlations with other Chinle records in the western U.S. reveal differences in the stratigraphic ranges of some spore-pollen taxa, likely attributable to local/regional differences in environmental conditions, such as groundwater availability, precipitation, nutrients, and temperature, rather than stratigraphic miscorrelation. This is interpreted as a consequence of environmental stress resulting from increased aridity coincident with the northward movement of Pangaea. Similarly, major differences between the western and eastern U.S. and northwest Europe can be attributed to floral provincialism governed by climatic zones during the Late Triassic.

Palm Pollen (!) From Barremian/Albian Cretaceous Patagonia

Early Cretaceous palm pollen tetrads from Patagonia, Argentina

Authors:

Martinez et al

Abstract:

Pollen tetrads and monads of spiny pollen grains with close affinities to palms have been found in several localities from the Lower Cretaceous (Barremian-Albian) of the Austral Basin (Magallanes), Patagonia (Argentina). When found dispersed, spiny and zonasulcate pollen grains, are commonly referred to the fossil genus Spinizonocolpites Muller, with close affinities to the extant palm Nypa. The Patagonian specimens were compared with fossil and extant members of the Arecaceae, showing close similarities in shape and sculpture with the primitive members of the subfamily Calamoideae. Nypa produces tetragonal tetrads different from the tetrahedral tetrads of the Spinizonocolpites-type recovered from Patagonia. The specimens were studied with LM and SEM. The polarity, aperture orientation and tetrad type allow segregating the Patagonian grains from the Nypoideae and relating it to the Calamoideae subfamily. These records suggest an antique origin of monocots and a probably initial diversification of calamoid palms during the Early Cretaceous in high latitudes of Gondwana. The presence of palmae during the Early Cretaceous in southern South America suggests a warm and humid climate, similar to that found in present days at tropics.

Climate Variability during the Carnian Pluvial Phase (Carnian Triassic Wet Phase)

Climate variability during the Carnian Pluvial Phase — A quantitative palynological study of the Carnian sedimentary succession at Lunz am See, Northern Calcareous Alps, Austria

Authors:

Mueller et al

Abstract:

The Middle and Upper Triassic prevailing dry climate was interrupted by a global phase of increased humidity during the Early Carnian, the Carnian Pluvial Phase (CPP). It started at the Julian 1–2 boundary and lasted approximately until the latest Julian or early Tuvalian. In the Tethys this is reflected by a change from limestone deposits to, first, organic rich mudstones and then to siliciclastics. The CPP occurred along the northern rim of the Tethys and is reported from many locations within and surrounding Europe. In this study samples from Lunz am See in Austria were analyzed for palynology and for bulk carbon isotope values covering a 450 m thick succession. A known − 3‰ bulk organic carbon isotope excursion, possibly as a result of the eruption of large amounts of volcanogenic material, in the Göstling Member and the basal Reingraben Formation has been confirmed. A total of five distinctive palynology assemblages were recognized and correlated regionally. While the under- and overlying formations yield terrestrial and subordinate also marine palynomorphs, the palynoflora of the Lunz Formation is near wholly terrestrial in origin. Climate trends were inferred from multivariate statistical analysis (PCA) of the palynofloral record. Palynomorphs show a general trend from a dry climate during the Julian 1 to wetter conditions during the Julian 2. The wetter conditions were periodically interrupted by shorter periods of dryer climate. In terms of temperature trends the climate was warmer during the early Julian 2 which corresponds with the deposition of the Reingraben Formation, temperature decreased again and remained fairly stable during most of later part of the Julian 2, which corresponds to the deposition of the Lunz Formation. This study correlates with similar observations from other locations from the western Tethys region that support the theory of a wide-ranging to global Carnian Pluvial Phase.

Neandertals Liked to Collect Flowers in Iraq

Marta Fiacconi and Chris Hunt have undertaken an analysis of pollen samples from the surface of the sediments of Shanidar Cave, Iraq.

Shanidar is one of the most important Neandertal sites known in West Asia, with the partial skeletons of nine Mousterian individuals. The excavator, Ralph Solecki, and Arlette Leroi-Gourhan claimed that flowers may have been deposited deliberately with one of the Neandertal bodies, Shanidar IV. The evidence was unusual concentrations of pollen within the sediment surrounding the skeleton.a

link.

Diverse Flowering Plant Pollen Found in Albian Cretaceous China

Palynology of the Early Cretaceous Hanxia Section in the Jiuquan Basin, Northwest China: The discovery of diverse early angiosperm pollen and paleoclimatic significance

Authors:

Zhang et al

Abstract:

The Lower Cretaceous deposits of the Jiuquan Basin (Northwestern China) located in central Asia are famous for the abundant and diverse fossil products with distinct characteristics of Jehol Biota. However, few early angiosperm remains have been published in their entirety. This study presents a palynomorph record from the recently reported fossil-bearing Zhonggou Formation of the Hanxia Section in the Jiuquan Basin. Here, we first discovered abundant and diverse angiosperm pollen with 16 taxa, which can be classified into four morphological types: tricolpate, polyaperturate, monosulcate and etrachotomocolpate apertures. The palynomorph assemblages contain a large number of biostratigraphically significant palynomorphs, such as numerically abundant tricolpate and rare polyaperturate angiosperm pollen grains, which indicate an Early Albian age for the Zhonggou Formation of the Hanxia Section. The overall palynomorph assemblage is dominated by the Perinopollenites, followed by the Classopollis; bisaccate pollen indicate Taxodiaceae-dominant vegetation types. As such, a relatively temperate and humid climatic condition is suggested for this area. Furthermore, two palynomorph assemblages can be distinguished in a stratigraphically upward order with an obviously increasing Classopollis content, indicating a gradual aridification trend during the Early Albian. This climatic change may affect the diversification of early angiosperms based on the correlation with the stratigraphic distribution of discovered angiosperm pollen.

What Environment did Miocene Neogene ape Lufengpithecus lufengensis Live in?

Pollen evidence of the palaeoenvironments of Lufengpithecus lufengensis in the Zhaotong Basin, southeastern margin of the Tibetan Plateau

Authors:

Chang et al

Abstract:

Evolutionary processes in hominoid primates were closely related to global and/or regional environmental changes, and therefore palaeoenvironmental reconstruction is fundamental for understanding how environmental changes shaped their evolution. Here, we present pollen data from the 16-m-thick Shuitangba (STB) section, Yunnan Province, southwestern China, bearing remains of the hominoid Lufengpithecus lufengensis of the terminal Miocene; and use principal component analysis to reconstruct the palaeovegetation and palaeoclimate during the key period when the hominoid lived. Our results show that before the STB hominoid appeared (Zone A), the vegetation was dominated by subtropical evergreen broad-leaved taxa with a few temperate deciduous taxa (e.g., Quercus, Castanea/Castanopsis, Alnus). The development of aquatic plants commencing at the ~ 12 m depth is a prominent feature, indicating a warm and humid climate. During the time when the hominoid lived (Zone B), evergreen broad-leaved forests with evergreen Quercus were predominant, while grasses including Poaceae began to expand, and simultaneously conifers decreased, indicating a warm climate. The significant presence of aquatic pollen taxa in subzone A-2 and Zone B suggests the occurrence of lacustrine or swampy environments. In contrast, in Zone C, the vegetation changed to coniferous forest, indicating cooler and drier conditions. These results provide substantive evidence of the vegetation conditions when the hominoid lived, suggesting that the greater diversity of vegetation and the warm humid climate, compared to the present day, would have favoured its survival.

Pollen Evidence Suggests Late Eocene Paleogene Hoh Xil Basin (Tibet) was Below 2,000 m

A Late-Eocene palynological record from the Hoh Xil Basin, northern Tibetan Plateau, and its implications for stratigraphic age, paleoclimate and paleoelevation

Authors:

Miao et al

Abstract:

The Hoh Xil Basin, lying in the central Tibetan Plateau, is key to understanding the Cenozoic tectonics, paleoelevation and paleoclimate changes that have occurred in the Tibetan Plateau since the collision of the Indian and Asian tectonic plates. However, the stratigraphic age and paleoelevation indicated by the sediments of the Hoh Xil Basin remain hotly debated. Here we report on one palynological record from the TTH-C section, extracted from the Yaxicuo Group (the stratigraphic unit between the Fenghuoshan and Wudaoliang groups), and analyze its implications for stratigraphic age, paleoclimate and paleoelevation in the Hoh Xil Basin. The record shows that palynological taxa are mainly dominated by xerophytic Ephedripites, Nitrariadites (Nitrariapollis) and Chenopodipollis, with few ferns and conifers. Rich morphologies correspond well with those in the Xia Ganchaigou Formation (Fm) of the Qaidam Basin to the north. Palynological percentages are well correlated with the middle member of the Xia Ganchaigou Fm in the Qaidam Basin as well as the lower member of the Mahalagou Fm in the Xining Basin to the northeast. The ages of the middle member of the Xia Ganchaigou and lower member of the Mahalagou Fms from these two basins are both identical to the Bartonian Stage (~ 40-37 Ma) of the Late Eocene, according to their respective high-resolution magnetostratigraphic dating. This means that the age of the Yaxicuo Group at least covers the Bartonian Stage. Besides the Qaidam and Xining basins, the palynological assemblages of the TTH-C section are also similar to those of three other sites (the Jiuquan, Tu-ha and Hetao basins), indicating similarly arid climates dominated by a northwestern Chinese subtropical high, and a relatively low paleoelevation in the Hoh Xil Basin (mostly less than 2,000 m a.s.l.) in the Late Eocene.

Evidence of Namibia's Neogene Aridification From Offshore Samples

Miocene-Pliocene Vegetation change in south-western Africa (ODP Site 1081, offshore Namibia)

Authors:

Hoetzel et al

Abstract:

Aridification is an important component of Late Neogene climate change in south-western Africa probably caused by modifications in the atmospheric circulation in relation to the initiation and intensification of the Benguela Upwelling System due to globally steepening of the meridional pressure gradient. Intensification of the meridional pressure gradient influenced the climate intensively which had then an impact on the vegetation. However, vegetation changes of south-western Africa from the Miocene to Pliocene have not yet been reported and only indirectly investigated by sedimentological data. Here, we present a pollen record of marine ODP Site 1081 retrieved 160 km offshore Namibia covering the time between 9 and 2.7 Ma. Using an endmember unmixing model we distinguished three vegetation phases: a relative wet phase, during the Tortonian, showing higher representations of Cyperaceae, a transition phase during the Messinian, when especially grasses expanded, and a dry one covering the Pliocene with a strong representation of desert and semi-desert plants. The three phases indicate ongoing aridification probably caused by intensified meridional pressure gradients. Additionally, aquatic vegetation indicators appear in our pollen record from around 5 Ma on, which we attribute to a relocation of the lower course of the Cunene River to its modern outlet in the Atlantic Ocean. Redirection of the Cunene River toward the Atlantic would have deprived the palaeolake Cunene of an important source of fresh-water ultimately resulting in desiccation of the lake and the formation of the Etosha Pan.

Pollen Hints at the Aptian/Albian Cretaceous Botanical Diversity & Turnover of Spain

Palynology of Aptian and upper Albian (Lower Cretaceous) amber-bearing outcrops of the southern margin of the Basque-Cantabrian basin (northern Spain)

Authors:

Barrón et al

Abstract:

The Lower Cretaceous deposits of the southern margin of the Basque-Cantabrian basin (northern Spain) are characterised by continental deposits interbedded with amber-bearing marine-influenced facies. These facies crop out in various localities and have yielded well-preserved palynological assemblages. The palynoflora is dominated by gymnosperm pollen grains, and shows relatively diversified spore content but scarce dinoflagellate cysts. The palynofloral evidence and regional geological setting indicate that the studied successions are dated as Aptian (Montoria-La Mina outcrop) and late Albian (Peñacerrada 1 and 2 and Salinillas de Buradón outcrops, and the Pancorbo site). Angiosperm pollen does not constitute a significant part of the Aptian assemblages but becomes diversified and numerically abundant in those dated as late Albian. Although broadly similar to contemporaneous palynofloras from eastern Spain, the Aptian assemblages of Montoria-La Mina do not yield tricolpate angiosperm pollen. Conversely, the inferred late Albian assemblages show a high content in polyaperturate angiosperm pollen grains, as occurs in other localities in Portugal, Western Europe and North America. The studied palynoflora shows significant differences from published assemblages located further north, in western France and Canada.

Tibetan Plataeu Zanda Basin was Significantly Lower in the Early Plioecene Neogene

Early Pliocene paleo-altimetry of the Zanda Basin indicated by a sporopollen record

Authors:

Wu et al

Abstract:

Whether the uplift of the Tibetan Plateau (TP) led to the origin and development of the Indian monsoon is still in dispute. A helpful indicator would be greater knowledge about the chronological development of paleo-altimetry. The Zanda Basin, located on the SW margin of the TP, forms one of the most extensive Cenozoic sedimentary basins in Tibet. The modern climate of this area is controlled by the Indian Monsoon circulation system. It is thus an appropriate region for the study of paleo-altimetry, in addition to research into the relation between the TP and the Indian Monsoon. Sporopollen analyses of early Pliocene lacustrine strata in the Zanda Basin show that gymnosperm pollen is dominant (av. 77%) and mainly composed of Picea (av. 27.2%) and Abies (av. 24.2%); fern spores occupy a lesser proportion (av. 17.6%), while angiosperm pollen including temperate, sub-tropical broadleaved trees, shrubs and herbs, accounts for only a small proportion of the assemblage. This sporopollen assemblage suggests that sub-alpine dark coniferous forests were distributed around the basin and grow in a cool and wet climate, rather than in a modern alpine steppe environment. These characteristics indicate that the Zanda Basin's altitude throughout the early Pliocene was most probably lower than it is at present.

Using Vegetation Patterns from the KT/K-Pg Mass Extinction for Comparison

The global vegetation pattern across the Cretaceous–Paleogene mass extinction interval: A template for other extinction events

Authors:

Vajda et al

Abstract:

Changes in pollen and spore assemblages across the Cretaceous–Paleogene (K–Pg) boundary elucidate the vegetation response to a global environmental crisis triggered by an asteroid impact in Mexico 66 Ma. The Cretaceous–Paleogene boundary clay, associated with the Chicxulub asteroid impact event, constitutes a unique, global marker bed enabling comparison of the world-wide palynological signal spanning the mass extinction event. The data from both hemispheres are consistent, revealing diverse latest Cretaceous assemblages of pollen and spores that were affected by a major diversity loss as a consequence of the K–Pg event. Here we combine new results with past studies to provide an integrated global perspective of the terrestrial vegetation record across the K–Pg boundary. We further apply the K–Pg event as a template to asses the causal mechanism behind other major events in Earths history. The end-Permian, end-Triassic, and the K–Pg mass-extinctions were responses to different causal processes that resulted in essentially similar succession of decline and recovery phases, although expressed at different temporal scales. The events share a characteristic pattern of a bloom of opportunistic "crisis" tax followed by a pulse in pioneer communities, and finally a recovery in diversity including evolution of new taxa.

Based on their similar extinction and recovery patterns and the fact that Last and First Appearance Datums associated with the extinctions are separated in time, we recommend using the K–Pg event as a model and to use relative abundance data for the stratigraphic definition of mass-extinction events and the placement of associated chronostratigraphic boundaries.

Evidence of a Significant Biological/Enviromental Event During the Upper Sinemurian Jurassic

Isotopic and palynological evidence for a new Early Jurassic environmental perturbation

Authors:

Riding et al

Abstract:

The Early Jurassic Epoch was a predominantly greenhouse phase of Earth history, but a comprehensive understanding of its climate dynamics is hampered by a lack of high resolution multi-proxy environmental records. Here we report a geologically brief (approximately several hundred thousand years) negative carbon isotope excursion (CIE) of 2–3‰ in both marine and terrestrial materials, recognised for the first time for the Late Sinemurian Substage (Early Jurassic, ~ 194 Ma) of eastern England. The Late Sinemurian carbon isotope excursion, which is termed the S-CIE herein, is accompanied by peaks in the abundance of the pollen grain Classopollis classoides and the dinoflagellate cyst Liasidium variabile. Classopollis classoides was thermophilic and is a reliable proxy for hot/warm climatic conditions. Liasidium variabile is interpreted as thermophilic and eutrophic using multivariate statistics, its fluorescence properties being similar to living heterotrophic dinoflagellate cysts, and its association with C. classoides. Moreover, the morphological and ecological similarities of L. variabile to the Cenozoic genus Apectodinium are noteworthy. The co-occurrence of the acmes of C. classoides and L. variabile with a negative CIE is interpreted here as having wide geographical significance due to the marine and terrestrial carbon isotope signals being precisely in phase within an open marine setting. This is consistent with an oceanic–atmospheric injection of isotopically-light carbon, coupled with global warming and increased marginal marine nutrient supply, possibly the result of increased precipitation due to an enhanced hydrological cycle or a seasonally-stratified water column. A probable sea level rise of at least regional extent has been identified at the L. variabile event in other records, which supports this putative phase of global warming. All these features are common to the Paleocene/Eocene thermal maximum (PETM, ~ 56 Ma), and there are also similarities with the Early Toarcian oceanic anoxic event (T-OAE, ~ 182 Ma).

Pollen Evidence of North Atlantic Current Moved South at the Start of the Pleistocene Quaternary Glaciations

Palynological evidence for a southward shift of the North Atlantic Current at ~2.6 Ma during the intensification of late Cenozoic Northern Hemisphere glaciations

Authors:

Hennissen et al

Abstract:

The position of the North Atlantic Current (NAC) during the intensification of Northern Hemisphere glaciation (iNHG) has been evaluated using dinoflagellate cyst assemblages and foraminiferal geochemistry from a ~260 kyr interval straddling the base of the Quaternary System from two sites: eastern North Atlantic Deep Sea Drilling Project Site 610 in the path of the present NAC, and central North Atlantic Integrated Ocean Drilling Program Site U1313 in the subtropical gyre. Stable isotope and foraminiferal Mg/Ca analyses confirm cooling near the marine isotope stage (MIS) G7–G6 transition (2.74 Ma). However, a continued dominance of the dinoflagellate cyst Operculodinium centrocarpum sensu Wall and Dale [1966] indicates an active NAC in the eastern North Atlantic for a further 140 kyr. At MIS 104 (~2.60 Ma) a profound dinoflagellate cyst assemblage turnover indicates NAC shutdown in the eastern North Atlantic, implying elevated atmospheric pressure over the Arctic and a resulting shift in the westerlies that would have driven the NAC. These findings challenge recent suggestions that there was no significant southward shift of the NAC or the polar front during iNHG, and reveal a fundamental climatic reorganization near the base of the Quaternary.

Vegetation and Climate Change Across the K-Pg Boundary in Seymour Island, Antarctica

Latest Cretaceous–earliest Paleogene vegetation and climate change at the high southern latitudes: palynological evidence from Seymour Island, Antarctic Peninsula

Authors:

Bowman et al

Abstract:

Fluctuations in Late Cretaceous climate were already influencing biotic change prior to the environmental upheaval at the Cretaceous–Paleogene (K–Pg) boundary, but their general nature, magnitude and timing remain controversial. A high-resolution dataset on terrestrially-derived palynomorphs is presented from the high southern palaeolatitudes that unlocks details of small-scale climate variability throughout this period of significant global change. Specifically, this is a quantitative spore and pollen analysis of an expanded uppermost Cretaceous to lowermost Paleogene (Maastrichtian–earliest Danian) shallow marine sedimentary succession from Seymour Island, off the northeastern tip of the Antarctic Peninsula, then (as now) located at ~ 65°S. Using nearest living relatives the first detailed vegetation, habitat and climate reconstruction is presented for the emergent volcanic arc at this time. On the coastal lowlands, a cool to warm temperate rainforest is envisaged growing in a riverine landscape, with both wet (river margin, pond) and relatively dry (interfluve, canopy gap) habitats. Diverse podocarps and southern beech trees grew alongside angiosperm herbs and shrubs in mean annual temperatures of ~ 10–15 °C. Higher altitude araucarian forests gave way to open ericaceous heathland, beyond the tree line, in subalpine to alpine conditions with mean annual temperatures of a cold ~ 5–8 °C. There is no exact modern botanical equivalent, but the closest modern flora is that of the Andes of southern Chile and Argentina. Maastrichtian climate is shown to have fluctuated from cool, humid conditions, through a rapid warming ~ 2 million years prior to the K–Pg transition, followed by cooling during the earliest Danian, a trend supported by previous work on this interval.

Icehouse to Greenhouse Paleoclimate Signals in Permian South African Palynological Records

Palynological records of the Permian Ecca Group (South Africa): Utilizing climatic icehouse-greenhouse signals for cross basin correlations

Authors:

Ruckwied et al

Abstract:

The Permian formations of the South African Karoo Basin play a crucial role in understanding Gondwana's climate history during this time of major global changes. In this paper we present two data sets, one from the coal-bearing Vryheid Formation (Witbank Basin) and one from the Whitehill and Upper Prince Albert formations of the DP 1/78 core (NE Karoo).

Main goal was to study the vegetation changes during this period of global warming and test if the climatic signals could be used to correlate the basinal Ecca group facies with the fluvio-deltaic coal-bearing strata of the Witbank Basin. The palynological record of the No. 2 Coal Seam of the Vryheid Formation indicates a cold climate, fern wetland community, characteristic of lowland alluvial plains, and an upland conifer community in the lower part of the coal seam. Up section, these communities are replaced by a cool-temperate cycad-like lowland vegetation and gymnospermous upland flora. The data set of the DP 1/78 core is interpreted to represent a cool to warm temperate climate represented by a high amount of Gangamopteris and Glossopteris elements.

Both data sets are very different in their composition, which can be explained by the differences in depositional environment, however our findings reveal a different age of the studied assemblages and thus also suggest that both data sets represent different stages in the transition from icehouse to greenhouse during Permian times. As the stratigraphic correlation between the Main Karroo Basin and the peripheral basins is still under discussion, this paper provides new data to underpin the stratigraphic placement of the Whitehill Formation relative to the coal-bearing Vryheid Formation.

Seven Angiosperm Pollen Species Recovered From Barremian/Aptian North China & Their Implications

The palynoflora of the Lower Cretaceous strata of the Yingen-Ejinaqi Basin in North China and their implications for the evolution of early angiosperms

Authors:

Zhang et al

Abstract:

A total of 41 spore species and 63 pollen taxa, including seven angiosperms, were identified from 24 samples of the Early Cretaceous succession (latest Barremian to Aptian) at the Wulan Section in the east part of the Yingen-Ejinaqi Basin, Inner Mongolia, China. In a stratigraphically upward order, three types of palynomorph assemblages were identified. Palynological assemblage I (PA I) was dominated by bisaccate pollen, whereas palynological assemblages II (PA II) and III (PA III) were characterised by abundant Classpollis associated with more spores. PA III contained the highest spore content. Angiosperm pollen display an increasing trend in diversity and abundance from PA I to PA III. PA I is most likely correlated to the Chinese Cretaceous palynofloral Transitional Zone and northern Disacciatrileti – Cicatricosisporites Province, whereas the assemblages II and III represent the transitional zone. The composition of these assemblages suggests that the climate was cool and humid within the basin during the latest Barremian, subsequently warmer and drier during the Early Aptian and, finally, became slightly wetter and warmer during the Late Aptian. Early angiosperm pollen occur frequently in this section, including that of Clavatipollenites, Asteropollis and Songipollis. On the stratigraphical order, these angiosperm pollen show a clear and continuous increase regarding the relative abundance and diversity of angiosperm, which most likely reflects the incipient dispersion of angiosperm plants during the latest Barremian to Late Aptian in inner East Asia. Lastly, a comprehensive compilation of published literature indicates that the emergence and evolution of early Asteropollis was not simultaneously worldwide, most likely occurring earlier in Eurasia than in other regions with a dramatic increase in both diversity and abundance prior to the emergence of tricolpate pollen.