Late Eocene to middle Miocene (33 to 13 million years ago) vegetation and climate development on the North American Atlantic Coastal Plain (IODP Expedition 313, Site M0027)

ArticleWe investigated the palynology of sediment cores from Site M0027 of IODP (Integrated Ocean Drilling Program) Expedition 313 on the New Jersey shallow shelf to examine vegetation and climate dynamics on the east coast of North America between 33 and 13 million years ago and to assess the impact of over-regional climate events on the region. Palynological results are complemented with pollen-based quantitative climate reconstructions. Our results indicate that the hinterland vegetation of the New Jersey shelf was characterized by oak–hickory forests in the lowlands and conifer-dominated vegetation in the highlands from the early Oligocene to the middle Miocene. The Oligocene witnessed several expansions of conifer forest, probably related to cooling events. The pollen-based climate data imply an increase in annual temperatures from ∼11.5 °C to more than 16 °C during the Oligocene. The Mi-1 cooling event at the onset of the Miocene is reflected by an expansion of conifers and mean annual temperature decrease of ∼4 °C, from ∼16 °C to ∼12 °C around 23 million years before present. Relatively low annual temperatures are also recorded for several samples during an interval around ∼20 million years before present, which may reflect the Mi-1a and the Mi-1aa cooling events. Generally, the Miocene ecosystem and climate conditions were very similar to those of the Oligocene. Miocene grasslands, as known from other areas in the USA during that time period, are not evident for the hinterland of the New Jersey shelf, possibly reflecting moisture from the proto-Gulf Stream. The palaeovegetation data reveal stable conditions during the mid-Miocene climatic optimum at ∼15 million years before present, with only a minor increase in deciduous–evergreen mixed forest taxa and a decrease in swamp forest taxa. Pollen-based annual temperature reconstructions show average annual temperatures of ∼14 °C during the mid-Miocene climatic optimum, ∼2 °C higher than today, but ∼1.5 °C lower than preceding and following phases of the Miocene. We conclude that vegetation and regional climate in the hinterland of the New Jersey shelf did not react as sensitively to Oligocene and Miocene climate changes as other regions in North America or Europe due to the moderating effects of the North Atlantic. An additional explanation for the relatively low regional temperatures reconstructed for the mid-Miocene climatic optimum could be an uplift of the Appalachian Mountains during the Miocene, which would also have influenced the catchment area of our pollen record.We thank the entire IODP Expedition 313 Scientific Party for input, and the IODP staff for support. We thank M. Drljepan, R. Zanatta, V. Menke, K. Reichel, and S. Namyslo for their assistance with preparing and processing the samples, and during photographing. Discussions with C. Bjerrum, J. Browning, T. Donders, L. Fang, M. Katz, Y. Milker, K. Miller, and P. Sugarman are gratefully acknowledged. Input from K. Dybkjær and anonymous reviewers was very much appreciated and contributed to a significant condensing of the manuscript. The German Science Foundation supported the research (DFG project KO 3944/3-1 to U. Kotthoff). Funding was also provided by NSERC Discovery Grants to F. M. G. McCarthy and to D. R. Greenwood respectively. NERC supported work by S. P. Hesselbo. This research used samples and/or data provided by the Integrated Ocean Drilling Program (IODP)

Arachnids in Bitterfeld amber: A unique fauna of fossils from the heart of Europe or simply old friends?

Bitterfeld amber, sometimes referred to as Saxon or Saxonian amber, is a potentially significant but poorly known source of arthropod data for the Palaeogene of northern Europe. An important aspect is a long-standing controversy about the age of this amber: namely whether it is equivalent to, and perhaps merely a southerly extension of, the better-known Baltic amber, or whether it is a unique and geological younger deposit sampling a different fauna. Here, we briefly review the Bitterfeld arachnids with particular emphasis on how these data could be used to elucidate the age of this deposit. Five arachnid orders have been recorded from Bitterfeld amber: spiders (Araneae), acariform mites (Acariformes), parasitiform mites (Parasitiformes), harvestmen (Opiliones) and pseudoscorpions (Pseudoscorpiones). This is a lower diversity than Baltic amber, where scorpions (Scorpiones) and camel spiders (Solifugae) have also been recorded. Spiders are the most comprehensively studied group, with more than 75 described species. Other groups such as pseudoscorpions and mites appear to be very diverse, but are virtually undescribed. Morphological overlap is apparent in the arachnid fauna and 40 species are currently shared between Baltic and Bitterfeld amber whilst 50 species are unique to the Bitterfeld deposit. At the family level overlap is even higher, but in all groups Baltic amber appears more diverse than Bitterfeld. This overlap may be interpreted as evidence for temporal conspecifity of the Baltic and Bitterfeld ambers, albeit with the Bitterfeld and Baltic ambers possibly representing independent localities within a larger Eocene European amber area which also included the Rovno amber from the Ukraine. However, caution should be exercised because the taxonomic foundation for such assumptions is far from comprehensive, most of the material remains to be studied in detail using modern techniques of morphological reconstruction. There are further issues with date estimates because some arachnid groups show extraordinary morphological stasis over time, even at species level, which may bias the analyses available. Here, we review the available knowledge on Bitterfeld arachnids and discuss how a detailed assessment of this fauna, and other arthropod taxa, could be generated. Several natural history museums – including Hamburg and Berlin – as well as private collectors host major assemblages of Bitterfeld fossils which may help to clarify the debate about the age and provenance of the material, and the extent to which (morpho)-species were maintained both over geographical distances and potentially geological time

First record of the spider family Hersiliidae (Araneae) from the Mesozoic of Europe (Bakony Mts, Hungary)

An adult male Hersiliidae spider is described from amber that originates from the Upper Cretaceous (Santonian) Ajka Coal Formation (Ajka-Csingervölgy, Hungary), the so-called ajkaite. The spider has elongate posterior spinnerets and a short third pair of legs III, both characteristics of the family, but differs from all known Mesozoic (discovered in burmite) and fossil and Recent European representatives of Hersiliidae so that a new genus and species name is proposed for Hungarosilia verdesi gen. et sp. nov. The new taxon is distinguishable by the following unique combination of characters: pro- and opisthosoma nearly circular in dorsal view; posterior spinnerets with a distal article more than three times longer than the basal article; pedipalpal tibia and patella short and stout but pedipalpal femur as long as the cymbium, cymbium egg-shaped and without cymbial apophysis; bulbus of circular shape in ventral view and slightly flattened is lateral view. The fossil represents the first record of Hersiliidae from the Mesozoic of Europe and establishes the second record of this family in the Mesozoic Era. The estimated paleoclimate and paleoflora of the Ajka coal sub-basin correspond well with habitat preferences of Recent relatives that are often arborical and found in association with tree bark. Overall, our findings highlight the importance of a neglected amber type, the ajkaite, for documenting and studying the European arthropod fauna during the Mesozoic

Pseudovector vs. pseudoscalar coupling in one-boson exchange NN potentials

We examine the effects of pseudoscalar and pseudovector coupling of the pi and eta mesons in one-boson exchange models of the NN interaction using two approaches: time-ordered perturbation theory unitarized with the relativistic Lippmann-Schwinger equation, and a reduced Bethe-Salpeter equation approach using the Thompson equation. Contact terms in the one-boson exchange amplitudes in time-ordered perturbation theory lead naturally to the introduction of s-channel nucleonic cutoffs for the interaction, which strongly suppresses the far off-shell behavior of the amplitudes in both approaches. Differences between the resulting NN predictions of the various models are found to be small, and particularly so when coupling constants of the other mesons are readjusted within reasonable limits.Comment: 24 pages, 4 figure

Marine resource abundance drove pre-agricultural population increase in Stone Age Scandinavia

How climate and ecology affect key cultural transformations remains debated in the context of long-term socio-cultural development because of spatially and temporally disjunct climate and archaeological records. The introduction of agriculture triggered a major population increase across Europe. However, in Southern Scandinavia it was preceded by ~500 years of sustained population growth. Here we show that this growth was driven by long-term enhanced marine production conditioned by the Holocene Thermal Maximum, a time of elevated temperature, sea level and salinity across coastal waters. We identify two periods of increased marine production across trophic levels (P1 7600–7100 and P2 6400–5900 cal. yr BP) that coincide with markedly increased mollusc collection and accumulation of shell middens, indicating greater marine resource availability. Between ~7600–5900 BP, intense exploitation of a warmer, more productive marine environment by Mesolithic hunter-gatherers drove cultural development, including maritime technological innovation, and from ca. 6400–5900 BP, underpinned a ~four-fold human population growth

The first fossils of the most basal pseudoscorpion family (Arachnida: Pseudoscorpiones: Pseudotyrannochthoniidae): evidence for major biogeographical shifts in the European paleofauna

Pseudoscorpions belong to the oldest terrestrial lineages with origins in the Devonian (ca. 385 Ma) but their fossil record is extremely sparse and little is known about their diversification over time. Here, we describe the first fossil species of the pseudoscorpion family Pseudotyrannochthoniidae that resemble the Devonian fossils in major details, such as the chaetotaxy of the pedipalps. We describe two new species, Allochthonius balticus sp. nov. from Baltic amber and Centrochthonius bitterfeldicus sp. nov. from Bitterfeld amber in northern Europe. Both species can unequivocally be assigned to extant genera and provide further evidence for dramatic range shifts in European invertebrate biota since the Paleogene. Allochthonius Chamberlin, 1929 is a diverse genus in eastern Asia (China, Korea, and Japan) today but does not occur anywhere in central Asia, Europe or North America. Centrochthonius Beier, 1931 is a poorly known genus but seems to be restricted to high altitude habitats in central Asia (China, Kyrgyzstan, and Nepal). With range retractions to regions more than 4600 km away from the European amber deposits, the fossils highlight total lineage extinction in Europe and survival in refugia that are climatically and botanically most similar to the Baltic amber forest of the Eocene. Overall, our results support the concept of morphological but potentially also ecological stasis in major pseudoscorpion lineages over long periods of time and agree with previous studies that suggested a warm temperate rather than subtropical or tropical climate for the time of amber deposition

The first fossil of the pseudoscorpion family Ideoroncidae (Arachnida: Pseudoscorpiones): A new taxon from the mid-Cretaceous of northern Myanmar

Pseudoscorpions have a sparse fossil record although they are among the oldest terrestrial lineages with origins that go back to the Devonian (ca. 385 Ma). Amongst the 25 extant families of pseudoscorpions, only 14 are known from fossils, most of which are preserved in European ambers from the Eocene. Burmese amber from the Cenomanian (mid-Cretaceous) of northern Myanmar is an important source of Mesozoic pseudoscorpion fossils but only six species have been described from this amber to date. In this paper, we establish the first fossil record for the pseudoscorpion family Ideoroncidae Chamberlin, 1930, which is coequally the oldest record of the pseudoscorpion superfamily Neobisioidea. The new genus Proalbiorix is established for the two species P. gracilis sp. nov. and P. compactus sp. nov. which already show all diagnostic features of members belonging to this family to date. Interestingly, Proalbiorix shows morphological features that align the fossils with present-day fauna from the Americas and Africa rather than Asia, which has biogeographical implications. Overall, the description provides another example of relative morphological stasis of pseudoscorpions compared to other arachnid lineages such as spiders, and that all major clades of pseudoscorpions were established long before the Cretaceous

The second chthonioid pseudoscorpion (Pseudoscorpiones: Chthoniidae) from mid-Cretaceous Burmese amber: a new genus with unique morphological features and potential Gondwanan affinities

Pseudoscorpions are amongst the oldest terrestrial lineages but there is a major gap in the fossil record between the oldest fossils from the Devonian (ca. 385 million years ago) and rich fossil communities in amber that mostly originate from the Eocene of Europe. Burmese/Myanmar amber (or Burmite) from the middle Cretaceous preserves a diverse community of pseudoscorpions but these remain poorly documented, despite their exceptional preservation and potential to offer unique insights into evolutionary history. Here we describe a new genus and species of pseudoscorpion with a unique morphology of the chelicerae, Prionochthonius burmiticus gen. et sp. nov., from Burmese amber. Although some key characters remain obscure, the fossil can be confidently attributed to the basal pseudoscorpion family Chthoniidae, but it cannot be assigned to any extant or other fossil genus. Based on trichobothria patterns, it is most similar to extant genera that are found only in the Southern Hemisphere; findings that are in line with previous studies suggesting Gondwanan origins for at least some of the Burmese amber invertebrates. The fossil provides further evidence for a diverse community of litter- and soil-dwelling pseudoscorpions in the Late Cretaceous that comprises many extinct genera but represents many of the modern families. It also suggests that the diversification of chthoniid pseudoscorpions occurred well before the middle Cretaceous, and that the principle gestalt of its members has changed relatively little over time