Palaeobotanical Evidence Research Articles

The Origin of Evergreen Broad-Leaved Forests in East Asia from the Evidence of Floristic Elements.

Arguments about the origin and evolution of the evergreen broad-leaved forests in East Asia exist generally, and are even contradictory in some cases. The origin and evolution of the flora of East Asia, especially in the evolutionary process, the formation time of the Asian monsoon, the implications of phylogenetic and biogeographic studies on some important taxa, and the implications of palaeobotanical evidence are debatable. Most research from different disciplines suggests that the monsoon in the Miocene was key to the diversification of East Asian flora and its evergreen broad-leaved forests. The common view is that the evergreen broad-leaved forests of East Asia are closely related to the monsoon's intensity and developments, which were caused by the uplift of Himalaya-Tibet during or after the mid-Miocene. Analysis of the floristic elements show that the present subtropical evergreen broad-leaved forests in East Asia could have an early or ancient tropical origin and a tropical Asian affinity, but that their species are dominated by endemic Chinese or East Asian ones, many of which have tropical Asian affinity or are tropical sister species. The time of Himalayan uplift and the intensity of the monsoon climate are believed to be key to the formation of the evergreen broad-leaved forests in East Asia. Combined with existing paleobotanical findings, the uplift of the Himalayas and the formation of the monsoon climate, as well as floristic elements of the subtropical evergreen broad-leaved forests, we believe that they evolved from an Asian tropical rainforest after the mid-Miocene in the southeastern region of East Asia, while the ancient subtropical evergreen broad-leaved forests in the southwestern region continuously evolved into the present subtropical ones.

Longitudinal population dynamics of Mediterranean-Atlantic Arbutus during the last 30 ka

The current distribution of the genus Arbutus in the Old World prompts questions about its long-term population dynamics, location and extent of refuge areas, and modern vulnerability in relation to climate change and human activity. Our work aims to address these questions by combining modern occurrence data with a comprehensive survey of pollen and macrofossil records. Range maps of past distribution have been produced for the last 32 ka to investigate geographical trends in population dynamics and the timing of the appearance of Arbutus across different biogeographical regions. In the Atlantic domain, Arbutus has been consistently present during the last 32 ka, even during the Last Glacial Maximum. In the central and eastern Mediterranean regions, it progressively increased since the beginning of the Holocene, appearing along the coasts of the Black Sea and in the Levant during the Middle Holocene. In addition, the dynamics of Arbutus in a number of peripherals stands (Ireland, Canary Islands, Cyrenaica, Crimea, and Black Sea coasts) is discussed. The palaeobotanical evidence suggests that the delayed emergence of eastern populations and peripheral stands in the fossil record may be ascribed to a very low population density, rather than to a sequential migration process from the western sectors of the range. The comparison of fossil records and modern occurrences highlights an overall temporal continuity between long-term persistence areas and current centers of gravity and calls for density-weighted ecological models that may contribute to an informed assessment of conservation actions and strategies.

First genome-wide data from Italian European beech (Fagus sylvatica L.): Strong and ancient differentiation between Alps and Apennines.

The European beech (Fagus sylvatica L.) is one of the most widespread forest trees in Europe whose distribution and intraspecific diversity has been largely shaped by repeated glacial cycles. Previous studies, mainly based on palaeobotanical evidence and a limited set of chloroplast and nuclear genetic markers, highlighted a complex phylogeographic scenario, with southern and western Europe characterized by a rather heterogeneous genetic structure, as a result of recolonization from different glacial refugia. Despite its ecological and economic importance, the genome of this broad-leaved tree has only recently been assembled, and its intra-species genomic diversity is still largely unexplored. Here, we performed whole-genome resequencing of nine Italian beech individuals sampled from two stands located in the Alpine and Apennine mountain ranges. We investigated patterns of genetic diversity at chloroplast, mitochondrial and nuclear genomes and we used chloroplast genomes to reconstruct a temporally-resolved phylogeny. Results allowed us to test European beech differentiation on a whole-genome level and to accurately date their divergence time. Our results showed comparable, relatively high levels of genomic diversity in the two populations and highlighted a clear differentiation at chloroplast, mitochondrial and nuclear genomes. The molecular clock analysis indicated an ancient split between the Alpine and Apennine populations, occurred between the Günz and the Riss glaciations (approximately 660 kyrs ago), suggesting a long history of separation for the two gene pools. This information has important conservation implications in the context of adaptation to ongoing climate changes.

Palaeobotanical evidence reveals the living conditions of Miocene Lufengpithecus in East Asia

BackgroundUnderstanding the relationship between human evolution and environmental changes is the key to lifting the veil on human origin. The hypothesis that environmental changes triggered the divergence of humans from apes (ca. 9.3–6.5 million years ago, Ma) has been poorly tested because of limited continuous environmental data from fossil localities. Lufengpithecus (12.5-6.0 Ma) found on the southeastern margin of the Tibetan Plateau (SEMTP) across the ape–human split provides a good chance for testing this hypothesis.ResultsHere, we reconstructed the habitats of L. keiyuanensis (12.5–11.6 Ma) with comprehensive vegetation, climate, and potential food web data by palaeobotanical evidence, together with other multidisciplinary data and partly tested the environment-driven hypothesis by revealing the living conditions of Lufengpithecus.ConclusionA detailed comparison of hominoids on different continents reveals their behaviour and fate divergence across the ape–human split against the background of global climate change, i.e., the stable living conditions of SEMTP not only provided a so-called ‘refuge’ for arboreal Lufengpithecus but also acted as a ‘double-edged sword’, preventing their further evolution while vegetation shifts in East Africa probably stimulated the emergence of human bipedalism, and the intense climatic changes in Europe possibly prevented those hominoids from surviving that time interval. Our findings provide interesting insight into the environmental impacts on the behavioural evolution of hominoids.

Middeleeuwse ijzer- en houtskoolproductie op de Veluwe

Medieval iron and charcoal production in the Veluwe region Recent research on the iron production landscape in the coppice wood of ‘t Asselt near Rheden (Southeastern Veluwe) Between the seventh and twelfth century ad large-scale iron production took place in the Veluwe region (Central Netherlands) based on the extraction of iron-rich loam concretions in the regional ice-pushed ridges. This iron production required large amounts of charcoal which were produced by the large-scale burning of semi-natural and/or coppice woods. There is palaeobotanical evidence that the woodland vegetation of the Veluwe diminished by two-thirds in this medieval period, partly because of medieval woodland reclamations, partly because of charcoal-burning. A master thesis project revealed the existence of an extensive and largely untouched iron production landscape in the coppice wood of ‘t Asselt (Southeastern Veluwe). Based on ceramics from the eighth-twelfth century, historical-geographical relics as well as written evidence this early and high medieval landscape layer seems rather complete and untouched, which makes it a very promising site for further archaeological research on medieval iron production landscapes.

Palaeobotanical evidence for Artinskian wildfire in the Talcher Coalfield, Mahanadi Basin, India

Palaeobotanical evidence for Artinskian wildfire in the Talcher Coalfield, Mahanadi Basin, India

Pedosedimentary record of MIS 5 as an interplay of climatic trends and local conditions: Multi-proxy evidence from the Palaeolithic site of Moravský Krumlov IV (Moravia, Czech Republic)

Only a few loess–palaeosol sequences from the last climatic cycle (Eemian-Weichselian) in East-Central Europe have been studied and correlated with up-to-date stratigraphic frameworks such as marine isotope stages (MIS) and Greenland Stadials/Interstadials (GS/GI). This paper examines the relations of local conditions and climatic trends to soil development, and the character of vegetation during MIS 5 period at the Palaeolithic site Moravský Krumlov IV. To revise the chronostratigraphy and interpretation of palaeosols, we applied a multi-proxy approach based on soil micromorphology, physical and geochemical analyses together with palaeobotanical evidence and results of optically stimulated luminescence dating. The part of the loess–palaeosol sequence under study was correlated with the Dolní Věstonice sequence and represents a time span from MIS 5e to MIS 5b. It comprises an Eemian luvisol (MIS 5e, Interglacial), an Early Weichselian chernozem (MIS 5e, GI 25) and a colluvium with a pedogenic imprint (MIS 5d, GI 24), loess (MIS 5d, GS 24), regosol (MIS 5c/5d, GI 23), and loess deposits (MIS 5c, GS 23). Unlike for the Dolní Věstonice, the record of MIS 5a has not been proved and there are no markers dividing individual palaeosols. The intensity of weathering is similar to comparable records from the Czech Republic and is elevated compared to Hungarian loess–palaeosol sequences. Evidence of forest vegetation with both deciduous and coniferous trees (MIS 5e, Interglacial) is followed by that of a steppe environment with a mosaic of trees (MIS 5e, GI 25) and, finally, a tundra or forest-tundra vegetation (MIS 5d, GI 24). Eemian luvisol is rarely preserved but recorded in contemporary sequences from the Czech Republic. The Early Weichselian part is rather similar to the record documented across sites in Lower Austria, in contrast to sites from the Czech Republic, and does not fit into the earlier established system of pedocomplexes.

Lycopodium root meristem dynamics supports homology between shoots and roots in lycophytes.

Roots have played a pivotal role in the conquest of land by vascular plants, yet their origin has remained enigmatic. Palaeobotanical evidence suggests that roots may have originated from subterranean shoots in some lycophyte species. If this hypothesis is correct, it would follow that the roots and shoots of extant lycophytes share fundamental developmental mechanisms. We tracked meristem dynamics in root and shoot apices of Lycopodium clavatum using a thymidine analogue and expression patterns of histone H4, respectively. Then we compared the meristem dynamics of roots and shoots to identify developmental similarities. Both apical meristems contained a quiescent tissue characterised by a low frequency of cell division. Actively dividing cells appeared in the quiescent tissue during dichotomous branching of both roots and shoots. As a result, the parental meristem divides into two daughter meristems, which give rise to new root or shoot apices. These striking similarities in meristem dynamics provide new neobotanical data that support the shoot-origin hypothesis of lycophyte roots. Although Lycopodium roots may have originated from subterranean shoots of Devonian lycophytes, these shoots may have changed into root-bearing axes in other extant lycophyte lineages.

The delayed and geographically heterogeneous diversification of flowering plant families.

The Early Cretaceous (145-100 million years ago (Ma)) witnessed the rise of flowering plants (angiosperms), which ultimately lead to profound changes in terrestrial plant communities. However, palaeobotanical evidence shows that the transition to widespread angiosperm-dominated biomes was delayed until the Palaeocene (66-56 Ma). Important aspects of the timing and geographical setting of angiosperm diversification during this period, and the groups involved, remain uncertain. Here we address these aspects by constructing and dating a new and complete family-level phylogeny, which we integrate with 16 million geographic occurrence records for angiosperms on a global scale. We show substantial time lags (mean, 37-56 Myr) between the origin of families (stem age) and the diversification leading to extant species (crown ages) across the entire angiosperm tree of life. In turn, our results show that families with the shortest lags are overrepresented in temperate and arid biomes compared with tropical biomes. Our results imply that the diversification and ecological expansion of extant angiosperms was geographically heterogeneous and occurred long after most of their phylogenetic diversity originated during the Cretaceous Terrestrial Revolution.

Recurrent palaeo-wildfires in a Cisuralian coal seam: A palaeobotanical view on high-inertinite coals from the Lower Permian of the Paraná Basin, Brazil.

Distribution and abundance of charcoal in coal seams (in form of pyrogenic macerals of the inertinites group) have been considered as a reliable tool to interpret the local and regional palaeo-wildfire regimes in peat-forming depositional environments. Although the occurrence of inertinites is globally well documented for the Late Palaeozoic, the description of palaeobotanical evidence concerning the source plants of such charcoal is so far largely missing. In the present study, we provide the first detailed analysis of macro-charcoal preserved in the Barro Branco coal seam, Rio Bonito Formation, Cisuralian of the Paraná Basin, Santa Catarina State, Brazil. Charcoal, in form of macro-charcoal and inertinites, was documented in all the six coal-bearing strata that compose the succession, confirming the occurrence of recurrent palaeo-wildfires during its deposition. Reflectance values indicated a mean charring temperature reaching ~515°C (and up to 1,045°C in excess) and the macro-charcoal exhibits anatomical features of secondary xylem of Agathoxylon. Combination of results derived from palaeobotanical and petrological data demonstrates that gymnosperm-dominated vegetation was repeatedly submitted to fire events and reinforced the hypothesis that Gondwanan mires were high-fire systems during the Cisuralian.

A new species of Liquidambar (Altingiaceae) from the late Eocene of South China.

A new fossil leaf species, Liquidambar bella (Altingiaceae), is described from the lower part of the Eocene Huangniuling Formation, Maoming Basin, South China. Suprabasal venation in the fossil lobed Liquidambar leaves is reported for the first time. The new species provides additional palaeobotanical evidence on the morphological variability of this genus supporting the idea of combining the genera Liquidambar, Semiliquidambar and Altingia into the single genus Liquidambar as proposed based on molecular markers.

Early Mississippian evaporites of coastal tropical wetlands

AbstractExtensive evaporites in Lower Mississippian successions from palaeoequatorial regions are commonly used as evidence for an arid to semi‐arid palaeoclimate. However, in this article, detailed studies of evaporites and their context refute this interpretation. Detailed sedimentological and petrographical analysis of the Lower Mississippian of northern Britain, is combined with archived log data from more than 40 boreholes across southern Scotland, northern England and Northern Ireland, and published literature from Canada. Two key cores from the Tweed Basin and the northern margin of the Northumberland – Solway Basin contain 178 evaporite intervals and reveal twelve distinct forms of gypsum and anhydrite across seven facies that are associated with planar laminated siltstone and intercalated thin beds of ferroan dolostone. Nodular gypsum and anhydrite, typically in intervals <1 to 2 m thick, are integral components of the succession. Nodular evaporite occurs within about 1 m of a palaeosurface, but most evaporite deposits represent ephemeral brine pans to semi‐permanent hypersaline lakes or salinas on a floodplain that was subjected periodically to storm surges introducing marine waters. Formation of evaporites under a strongly seasonal climate in a coastal wetland is supported by palaeosol types and geochemical proxies, and from palaeobotanical evidence published previously. Although 65% of modern equatorial areas experience a strongly seasonal climatic regime, salinas and sabkhas are a minor component today in comparison with the evidence from these Lower Mississippian successions. This implies that the earliest terrestrial environments were complex and dynamic, providing a diverse range of habitats in which the early tetrapods became terrestrialized and represent a setting that is rarely preserved in the geological record.

Constraining uncertainty in the timescale of angiosperm evolution and the veracity of a Cretaceous Terrestrial Revolution.

Summary Through the lens of the fossil record, angiosperm diversification precipitated a Cretaceous Terrestrial Revolution (KTR) in which pollinators, herbivores and predators underwent explosive co‐diversification. Molecular dating studies imply that early angiosperm evolution is not documented in the fossil record. This mismatch remains controversial.We used a Bayesian molecular dating method to analyse a dataset of 83 genes from 644 taxa and 52 fossil calibrations to explore the effect of different interpretations of the fossil record, molecular clock models, data partitioning, among other factors, on angiosperm divergence time estimation.Controlling for different sources of uncertainty indicates that the timescale of angiosperm diversification is much less certain than previous molecular dating studies have suggested. Discord between molecular clock and purely fossil‐based interpretations of angiosperm diversification may be a consequence of false precision on both sides.We reject a post‐Jurassic origin of angiosperms, supporting the notion of a cryptic early history of angiosperms, but this history may be as much as 121 Myr, or as little as 23 Myr. These conclusions remain compatible with palaeobotanical evidence and a more general KTR in which major groups of angiosperms diverged later within the Cretaceous, alongside the diversification of pollinators, herbivores and their predators.

Alto de Ballester, biogeographical consequences of atypical MN 3 micromammal assemblages from eastern Spain

The small mammal assemblages from Alto de Ballester 1 and 2 in the Rubielos de Mora basin represent a unique faunal assemblage from the late early Miocene (Ramblian, MN 3). Together, the assemblages yielded five species of rodents (Peridyromys murinus, P. aff. murinus, P. aquatilis, Pseudotheridomys aff. fejfari and cf. Steneofiber depereti), and nine insectivores (Galericinae indet., Desmanella fejfari, Myxomygale minor, Desmanodon daamsi, Chainodus cf. sulcatus, Heterosorex sp., cf. Oligosorex thauensis, cf. Clapasorex alvarezae, and Paenelimnoecus cf. truyolsi). High abundance and diversity of insectivores, and the presence of a beaver and a dimylid show that the assemblages represent a humid, forested environment. This is in line with the palaeobotanical evidence of the basin. The two Alto de Ballester assemblages, which are very different from other Ramblian faunas, show that there was a variety of ecosystems on the Iberian Peninsula at this period, probably drier in the inland and more humid near the coastal zone.

Phylogenetic and paleobotanical evidence for late Miocene diversification of the Tertiary subtropical lineage of ivies (Hedera L., Araliaceae)

BackgroundHedera (ivies) is one of the few temperate genera of the primarily tropical Asian Palmate group of the Araliaceae, which extends its range out of Asia to Europe and the Mediterranean basin. Phylogenetic and phylogeographic results suggested Asia as the center of origin and the western Mediterranean region as one of the secondary centers of diversification. The bird-dispersed fleshy fruits of ivies suggest frequent dispersal over long distances (e.g. Macaronesian archipelagos), although reducing the impact of geographic barriers to gene flow in mainland species. Genetic isolation associated with geographic barriers and independent polyploidization events have been postulated as the main driving forces of diversification. In this study we aim to evaluate past and present diversification patterns in Hedera within a geographic and temporal framework to clarify the biogeographic history of the genus.ResultsPhylogenetic (biogeographic, time divergence and diversification) and phylogeographic (coalescence) analyses using four DNA regions (nrITS, trnH-psbA, trnT-trnL, rpl32) revealed a complex spatial pattern of lineage divergence. Scarce geographic limitation to gene flow and limited diversification are observed during the early-mid Miocene, followed by a diversification rate increase related to geographic divergence from the Tortonian/Messinian. Genetic and palaeobotanical evidence points the origin of the Hedera clade in Asia, followed by a gradual E-W Asian extinction and the progressive E-W Mediterranean colonization. The temporal framework for the E Asia - W Mediterranean westward colonization herein reported is congruent with the fossil record. Subsequent range expansion in Europe and back colonization to Asia is also inferred. Uneven diversification among geographic areas occurred from the Tortonian/Messinian onwards with limited diversification in the newly colonized European and Asian regions. Eastern and western Mediterranean regions acted as refugia for Miocene and post-Miocene lineages, with a similar role as consecutive centers of centrifugal dispersal (including islands) and speciation.ConclusionsThe Miocene Asian extinction and European survival of Hedera question the general pattern of Tertiary regional extinction of temperate angiosperms in Europe while they survived in Asia. The Tortonian/Messinian diversification increase of ivies in the Mediterranean challenges the idea that this aridity period was responsible for the extinction of the Mediterranean subtropical Tertiary flora. Differential responses of Hedera to geographic barriers throughout its evolutionary history, linked to spatial isolation related to historical geologic and climatic constraints may have shaped diversification of ivies in concert with recurrent polyploidy.

Palaeobotanical redux: revisiting the age of the angiosperms.

Angiosperms (flowering plants) are the most diverse of all major lineages of land plants and the dominant autotrophs in most terrestrial ecosystems. Their evolutionary and ecological appearance is therefore of considerable interest and has significant implications for understanding patterns of diversification in other lineages, including insects and other animals. More than half a century ago, influential reviews showed that while angiosperms are richly represented in sediments of Late Cretaceous and younger ages, there are no reliable records of angiosperms from pre-Cretaceous rocks. The extensive new macrofossil, mesofossil, and microfossil data that have accumulated since have confirmed and reinforced this pattern. Recently, however, molecular dating methods have raised the possibility that angiosperms may have existed much earlier, and there have been scattered reports of putative angiosperms from Triassic and Jurassic rocks. Critical assessment of these reports shows that, so far, none provide unequivocal evidence of pre-Cretaceous angiosperms. Angiosperms may ultimately be recognized from Jurassic or earlier rocks, but credible palaeobotanical evidence will require unambiguous documentation of the diagnostic structural features that separate angiosperms from other groups of extant and extinct seed plants.

Habitat, climate and potential plant food resources for the late Miocene Shuitangba hominoid in Southwest China: Insights from carpological remains

The late Miocene is a sub-epoch when hominoids became rare worldwide but managed to survive in a few refugia. Investigating the living conditions of the late Miocene hominoids is therefore crucial for a better understanding of how they survived in those refugia. In this study, we present relevant palaeobotanical evidence regarding the habitat, climate and possible plant food resources for the Shuitangba hominoid (Lufengpithecus cf. lufengensis) from the late Miocene Zhaotong Basin, Southwest China. A total of 14 plant taxa were recognized from carpological remains newly recovered from the Zhaotong Basin, among which ten taxa were not reflected in the previous pollen record. These new plant taxa expand our knowledge of the flora and indicate how diverse the ecosystem in the late Miocene Zhaotong Basin was. Based on our carpological taxa, we hypothesize that the Shuitangba hominoid lived in a stratified mixed forest composed of trees, shrubs, lianas, herbs and grasses, near a lake occupied by various aquatic plants. The quantitative palaeoclimate reconstruction using the Coexistence Approach (CoA) indicates that the late Miocene Zhaotong Basin had a mean annual temperature (MAT) of 11.3–17.6°C and a mean annual precipitation (MAP) of 1042–1547mm, suggesting a mildly warm and humid climate for the Shuitangba hominoid. It also indicates that the hominoid had warm and wet summers but cool and dry winters, under the influence of the Asian monsoon. Edible and nutritious fruits and seeds of a considerable size, e.g., nuts of Carya and Corylus, fruits of Euryale and Trapa, were possibly exploited by the Shuitangba hominoid. The harder fruits, e.g., nuts of Carya and Corylus, might have benefited the hominoid as a fallback resource in winter when foods were scarce.

Land Use Affects Carbon Sources to the Pelagic Food Web in a Small Boreal Lake.

Small humic forest lakes often have high contributions of methane-derived carbon in their food webs but little is known about the temporal stability of this carbon pathway and how it responds to environmental changes on longer time scales. We reconstructed past variations in the contribution of methanogenic carbon in the pelagic food web of a small boreal lake in Finland by analyzing the stable carbon isotopic composition (δ13C values) of chitinous fossils of planktivorous invertebrates in sediments from the lake. The δ13C values of zooplankton remains show several marked shifts (approx. 10 ‰), consistent with changes in the proportional contribution of carbon from methane-oxidizing bacteria in zooplankton diets. The results indicate that the lake only recently (1950s) obtained its present state with a high contribution of methanogenic carbon to the pelagic food web. A comparison with historical and palaeobotanical evidence indicates that this most recent shift coincided with agricultural land-use changes and forestation of the lake catchment and implies that earlier shifts may also have been related to changes in forest and land use. Our study demonstrates the sensitivity of the carbon cycle in small forest lakes to external forcing and that the effects of past changes in local land use on lacustrine carbon cycling have to be taken into account when defining environmental and ecological reference conditions in boreal headwater lakes.

Going underground: postcranial morphology of the early Miocene marsupial mole Naraboryctes philcreaseri and the evolution of fossoriality in notoryctemorphians

We present the first detailed descriptions of postcranial elements of the fossil marsupial mole Naraboryctes philcreaseri (Marsupialia: Notoryctemorphia), from early Miocene freshwater limestone deposits in the Riversleigh World Heritage Area, northwestern Queensland. Qualitative functional analysis of these elements suggest that Na. philcreaseri was very well-adapted for burrowing, albeit somewhat less so than the living marsupial moles Notoryctes typhlops and N. caurinus. Quadratic discriminant analysis of limb measurements suggests that Na. philcreaseri was subterranean, and its Index of Fossorial Ability is almost identical to that of Notoryctes species, being among the highest known for any mammal. These results suggest that notoryctemorphians evolved their specialised, “mole-like” subterranean lifestyle prior to the early Miocene. Given that forested environments predominated in Australia until the middle-late Miocene, this transition to subterranean behaviour may have occurred via burrowing in forest floors, in which case fossorial mammals that live in tropical rainforests today (such as the placental golden moles Chrysospalax trevelyani and Huetia leucorhina) may represent reasonable living analogues for early notoryctemorphians. However, alternative scenarios, such as a cave-dwelling or semi-aquatic ancestry, should be considered. Phylogenetic analysis using a Bayesian total evidence dating approach places Naraboryctes as sister to Notoryctes with strong support (Bayesian posterior probability = 0.91), and indicates that Naraboryctes and Notoryctes diverged 30.3 MYA (95% HPD: 17.7-46.3 MYA). The age and known morphology of Na. philcreaseri does not preclude its being ancestral to Notoryctes. Using estimates of divergence times and ratios of nonsynonymous to synonymous substitutions per site, we infer that the nuclear gene “Retinol-binding protein 3, interstitial” (RBP3), which plays a key role in vision, became inactive in the Notoryctes lineage ~5.4 MYA (95% HPD: 4.5-6.3 MYA). This is much younger than previous published estimates, and postdates considerably the age of Na. philcreaseri, implying that RBP3 was active in this fossil taxon; hence, Na. philcreaseri may have retained a functional visual system. Our estimate for the inactivation of RBP3 in the Notoryctes lineage coincides with palaeobotanical evidence for a major increase in the abundance of grasses in Australia, which may indicate the appearance of more open environments, and hence selection pressure on notoryctemorphians to spend less time on the surface, leading to relaxed selection on RBP3. Ultimately, however, a fuller understanding of the origin and evolution of notoryctemorphians-including when and why they became “mole-like”-will require improvements in the Palaeogene fossil record of mammals in Australia

Palaeoclimatic and site-specific conditions in the early Permian fossil forest of Chemnitz—Sedimentological, geochemical and palaeobotanical evidence

As significant indicators of deep-time palaeoclimate, a number of new palaeontological, pedological and geochemical characteristics are provided for the Chemnitz Fossil Lagerstätte to depict more precisely its environmental conditions. For the first time, several lines of evidence indicate that this fossil forest, instantaneously preserved by volcanic deposits, once received an annual precipitation of around 800–1100mm, but grew on a nearly unweathered palaeosol. Although the composition of this rich and diverse T0 assemblage suggests a hygrophilous, dense and multi-aged vegetation dominated by conservative lineages, the habitat was affected by environmental disturbances and pronounced seasonality. Repeated changes in local moisture availability are suggested by geochemical proxies, the co-occurrence to intergrowth of calcic and ferric glaebules in the palaeosol and developmental traits of perennial vegetational elements. Specific substrate adaptation is reflected by different root systems and cyclic growth interruptions recorded in the stems, branches and roots of long-lived woody plants. Many differentially adapted terrestrial animals complete the more comprehensive reconstruction of a late Sakmarian ecosystem and its climatic and preservational controls. Albeit spatially confined, this diverse in-situ record may contribute to understand wetland–dryland dynamics of sub-tropical Northern Hemisphere Pangaea.