Paleontological Investigations Research Articles

Local and global controls on carbon and sulfur isotope records in the Middle Ordovician Epeiric sea successions of the Taebaeksan Basin, Korea

Although the sedimentary carbonate carbon isotope record is generally considered a reliable archive of long-term changes in the global carbon cycle, the influences of local variability in carbon cycling and diagenesis frequently overwhelm its global controls, particularly in shallow platform environments. During the Middle Ordovician period, the middle Darriwilian isotopic carbon excursion (MDICE) has been identified worldwide, including the Taebaeksan Basin in the Sino-Korean Block. However, in the eastern part of the Taebaeksan Basin, the positive δ13Ccarb trend associated with the MDICE was disrupted by negative δ13Ccarb anomalies, indicating the alternating prevalence between local and global controls. By comparing paired carbon and sulfur isotope signatures, we demonstrate the involvement of two distinct mechanisms in this local event: a gradual decrease in δ13Ccarb closely parallels that of organic carbon, and a negative δ13Ccarb peak, superimposed on the long-term δ13Ccarb decrease, coincides with the positive sulfur isotope shift in pyrite, without a corresponding change in δ13Corg. The latter indicates the formation of 13C-depleted authigenic carbonate during early diagenesis, associated with microbial sulfate consumption, whereas post-depositional processes cannot fully account for the coupled negative shifts in δ13Ccarb and δ13Corg values. Instead, this simultaneous divergence from the MDICE event may be due to limited exchange of dissolved inorganic carbon with open ocean water, coupled to an increase in terrestrial runoff, as shown by changes in the clay mineral assemblage. While generally aligning with sedimentological and paleontological investigations regarding the formation of restricted environments in the eastern part of the Taebaeksan basin, this interpretation challenges the previously presumed timing and duration of platform restriction. Our findings highlight that the spatial variability of isotopic records may compromise their fidelity as global proxies but offer valuable insights into the evolution of depositional environments and platform geometry, often obscured by sporadic outcrop exposure.

Quaternary evolution of the Meiji Atoll (Mischief Reef) in the southern South China Sea

This paper describes the Quaternary evolution of Meiji Atoll (also known as Mischief Reef) in the southern South China Sea. Findings are based on a sedimentological and paleontological investigation of the uppermost 150 m of core NK-1. Through the Quaternary, open-lagoon sediments initially developed from ca. 2.6 to 1.6 Ma, which were succeeded by backreef sediments from 1.6 to 1.1 Ma, and subsequently by reef-flat sediments from 1.1 Ma to present, as the atoll evolved. The deepest depositional environments occurred between 2.0 and 1.6 Ma as a result of significant rates of subsidence in the Dangerous Grounds area. Coral abundance steadily increased during the Quaternary due to the secular eustatic sea-level drop and continuous high temperatures in the southern South China Sea. After the start of the Mid-Pleistocene Transition from 1.25 Ma, there was an increase in the amplification of short-eccentricity glacio-eustatic cycles, which resulted in two impacts. First, more frequent exposure horizons developed over the atoll due to an increase in amplitude of short-term sea-level fall events. Second, the occurrence of the thickest coral framestone units developed at around 0.8 Ma, perhaps linked to prominent short-term sea-level highstands (i.e., 125-ka cycle) and moderate subsidence rates. In summary, we document the Quaternary evolution of the Meiji Atoll, and show how variations in sea surface temperature, eustatic sea level, and tectonics have influenced its development. These findings have broader implications for understanding the Quaternary evolution of similar tropical carbonate atolls in the region.

Taxonomy, biostratigraphy and paleoecology of non-marine ostracod fauna of the Maastrichtian intertrappean beds of the lower Narmada Basin, Malwa Plateau, India

Paleontological investigations in the Late Cretaceous sedimentary units associated with Deccan traps of the lower Narmada valley, western Central India were carried out in order to ascertain ostracod diversity and its biostratigraphic and paleoecological implications. Eighteen species of twelve genera of Cytheroidea, Darwinuloidea and Cypridoidea ostracods recovered from four sections of the Deccan intertrappean beds are described. The species include the specimens from two new intertrappean sections, Kakarda and Bara Bheralya and additional ostracod taxa recorded from two previously studied sections, Gujri and Uthawali. The biostratigraphic, taphonomic and paleoecological analysis of the newely recovered ostracod assemblage in conjunction with the recent published data from the study area depict Maastrichtian age and freshwater fluvio-lacustrine environment for the studied sections.

Geological record of 18th and 19th century tsunamis along the Japan Sea coast of Tsugaru Peninsula, northwestern Japan

Our stratigraphic and paleontological investigations revealed three sandy event deposits (E1, E2, and E3) within peaty clay at the Sotomeyachi site on the Japan Sea coast of Honshu (mainland of Japan), northwestern Japan. Visual examination and X-ray computed tomographic images of samples of the deposits provided evidence of strong currents characterized by rip-up mud clasts, load casts, and erosional lower stratigraphic contacts. Marine, brackish, and freshwater diatom species in the deposits indicate they were derived from various coastal sources. Radiocarbon dating constrained the ages of event deposit E2 to 1764–1902 CE and E3 to 1558–1845 CE, 1699–1918 CE, and 1704–1781 CE. According to historical records, the E2 deposits likely correspond to the tsunami generated by the 1833 Shonai-oki earthquake, and the E3 deposits correspond to a tsunami associated with either a submarine landslide associated with the 1741 Oshima-Oshima eruption or the 1793 Nishi-Tsugaru earthquake. Because our numerical simulation of the 1741 tsunami showed no significant inundation at the study site, it is more likely that the 1793 earthquake was responsible for tsunami deposit E3. The E1 deposit is discontinuous and showed different characteristics (absence of load structures, rip-up mud clasts and mixed diatom assemblages) to those of events E2 and E3, so it is unlikely to be a tsunami deposit.

Revised temporal and morphostratigraphic context for Clark Quarry: A late-Pleistocene, fluvially-reworked, Atlantic coast backbarrier deposit

Sediments along the Atlantic Coastal Plain (ACP) of North America have been the focus of numerous paleontological investigations and yielded a diverse array of vertebrate remains; yet the depositional environments associated with their preservation are poorly understood. In this study, we present a multidisciplinary analysis of the depositional environment at Clark Quarry, a late-Pleistocene, fossil-rich locality located within the ACP in Georgia, USA. Clark Quarry is currently positioned 15 km west of the Atlantic Ocean coast and lies within the Princess Anne Terrace, a 100–80 ka paleobarrier-island complex. Fossil-bearing sediments at Clark Quarry are interpreted to have been deposited as a low-energy, fluvial environment that subsequently reworked low-lying terrain of the Princess Anne Terrace backbarrier. Interpretations of digital elevation models (DEM) and infrared stimulated luminescence (IRSL) ages on K-rich feldspar sand grains indicate that this region was an estuarine zone backing (i.e., westward) the Princess Anne paleobarrier island that was subsequently reworked by fluvial activity 68–52 ka. These new interpretations, paired with additional radiocarbon ages from fossil carbonates and overlying soil horizons, indicate that radiocarbon samples may have been influenced by isotopic exchange and should be interpreted as minimum age estimates. Additionally, ground-penetrating radar (GPR) surveys in conjunction with DEM analysis may have captured the subsurface signature of a meandering fluvial system transitioning to a braided style, emphasizing the dynamic nature of this depositional environment. Non-preferential orientation of excavated long bones suggests multidirectional paleoflow, further suggesting a braided stream influence. When considered in conjunction, these data: 1) indicate that Clark Quarry represents a spatially and temporally resolved window into the late-Pleistocene ecosystem in southeastern North America, and 2) suggest that existing radiocarbon data from late-Pleistocene ACP localities should be considered with caution.

Sedimentological, petrophysical, and geochemical controls on deep marine unconventional tight limestone and dolostone reservoir: Insights from the Cenomanian/Turonian oceanic anoxic event 2 organic-rich sediments, southeast Constantine Basin, Algeria

The Cenomanian/Turonian period is characterized by the deposition of organic-rich and fine-grained sediments that form important source rocks and unconventional reservoir units in North Africa and other parts of the world. The Lower Turonian deposits of the Djebel Darmoun Field, southeast Constantine Basin, Algeria, comprise a thick carbonate succession that has potential as an unconventional reservoir unit. This research aims to investigate the Lower Turonian succession in terms of microfacies, diagenesis, petrophysical, and geochemical characteristics, which were previously unknown. Sedimentological and diagenesis analyses were performed based on the core and thin section observations. Furthermore, geochemical and petrophysical analysis methods were carried out to assess the resource potential based on geochemical measurements, core measurements, and well logging evaluation in an arrangement. Based on sedimentological investigation, the Lower Turonian carbonate section is composed of tight limestone and dolostone rocks characterized by four bioclastic limestones and two dolomicrite microfacies, while paleontological investigation indicates that the faunal content is dominated by planktonic assemblages, revealing a pelagic deep marine setting environment. The primary pores of the Lower Turonian carbonate rocks are seldom preserved due to multi-stage diagenetic alteration (i.e., cementation, compaction, fracturing, dolomitization, dissolution, asphaltene), while dominant secondary pores are represented by dissolution-enlarged and open fractures/fissures, while intercrystal pores might be added in dolostone intervals. Dissolution and fracturing diagenetic events play a major role in enhancing the pore network, while compaction, cementation, and asphaltene diagenesis processes share in the obliteration of the petrophysical properties. Dolomitization played a dual role in the dolostone intervals, where it tended to develop the porosity at the early stages of diagenesis, while it tended to decrease the porosity at the latest diagenesis stages. The geochemical analysis indicated high amounts of organic matter in these intervals, where the higher estimated organic richness reaches a maximum TOC of 7.8% at the lowermost part. The petrophysical analysis inferred that the Lower Turonian carbonate sediments are characterized by low porosity (avg. 4%), very low permeability (<0.01mD), with dominant micro and meso porosities, and therefore they can be classified as tight carbonate unconventional resources. This study provides an insight into factors controlling the pore system network (microporosity) of fine-grained carbonate rocks as an excellent analog of the deep marine unconventional tight limestone and dolostone reservoirs and improves the knowledge and modeling of these unconventional resources. The study sheds light on the organic-rich sediments that are associated with oceanic anoxic events (OAEs) across the North African region and other parts elsewhere, forming high quality source rocks that might be neglected as excellent unconventional resources.

BIOSTRATIGRAPHY AND CORRELATION OF DEVONIAN DEPOSITS IN THE SOUTH-WEST SEGMENT OF THE EAST-EUROPEAN PLATFORM BY BRACHIOPODS

The main aim of the paper is to study the detailed distribution of the brachiopod fauna throughout the entire Devonian section from the Silurian-Devonian boundary at the Podilla region to the Devonian-Carboniferous boundary at the SW slope of the Dnipro-Donets Depression (DDD). The Devonian brachiopods (mainly Productids, Spiriferids and Rhynchonellids) of the south-west segment of the East-European Platform (EEP) are reviewed from the DDD, Volhyn-Podilla monocline (VPM) including the L’viv Paleozoic Trough, and Fore-Dobrogea Paleozoic Depression (FDPD). The faunas of these regions are mutually related and compared to the Devonian faunas of the EEP (Russia) and Pripyat’ Depression (Belarus). In recent years several paleontological investigations have broadened and deepened our knowledge of the Devonian biostratigraphy of Ukraine. Based on systematic studies of brachiopods from the SW segment of the EEP we recognize four successive faunas corresponding to four great marine transgressions — Early Devonian (Tiwer Series, the Monograptus uniformis Zone), Middle Devonian (Givetian Stage, the conodont varcus Zone), Late Frasnian (the conodont Upper rhenana — linguiformis Zone), and Early Famennian (the conodont triangularis-crepida Zone). The Early Devonian association includes Howellella angustiplicata, Plectodonta maria, and Daiya navicula and others which are similar to late Silurian brachiopods by their generic features (represented the genus common with the Upper Silurian). The Middle Devonian assemblages contain: Emanuella volhynica, Atrypa (Desquamatia) ventricosa, Chonetes sarcinulata, and Poloniproductus productoides at VPM sections (Givetian Stage, the varcus Zone), as well as Variatrypa sokolovae (Eifelian Stage), but in the DDD sections the impoverished association with Stringocephalus cf. burtini (Eifelian Stage) and Atrypa uralica (Givetian Stage) occur. The Late Frasnian association is represented by dominance of Theodossia tanaica, T. evlanensis, T. livnensis at all regions — VPM, DDD and FDPD (the Upper rhenana — linguiformis zones). The Early Famennian association is represented by ex Cyrtospirifer archiaci = Cyrtospirifer asiaticus and Cyrtospirifer ljachovichensis, Cyrtiopsis sp., Ptychomaletoechia zadonica, Iloerhynchus tichomirovi, Ardiviscus ex gr.herminae, Steinhagella annae etc. at DDD and by the same association plus Dmitria angustirostris at VPM (the triangularis-crepida zones). Brachiopods near the D-C boundary have been recorded so far from the black shales fossiliferous deeper water facies only in DDD: Spinocarinifera nigra, S. fallax, Sphenospira julii, Parallelora sp. (the Siphonodella praesulcata Zone). The result of our systematic study of productids, spiriferids, rhynchonellids, atrypids, and athyrids from Ukrainian sections are in perfect agreement with, and supplement to the previous investigations of Middle and Upper Devonian deposits at VPM and DDD, suggesting their important role for precising boundaries between the Devonian stages and horizons in SW segment of EEP. The essential role of brachiopods for the Devonian biostratigraphy and correlations with the East-European biozonation is confirmed.

A fossil terrestrial fauna from Tobène (Senegal) provides a unique early Pliocene window in western Africa

Early Pliocene hominin evolutionary scenarios proposed to date mostly rely on paleontological investigations from eastern Africa. Filling major geographical gaps in the fossil record could potentially invalidate these scenarios and stimulate development of improved theories. Based on published literature, no Pliocene fossil of continental vertebrates have been discovered in Western Africa and the situation is only slightly better in central and northern Africa. Here, we expand the Pliocene vertebrate continental fossil record to western Africa with the description of the Tobène fauna, a new fossiliferous Neogene locality from Senegal. We describe a diversity of large mammals, including at least ten taxa based on fragmentary remains recovered from alluvial channel deposits. Estimation based on weathering events and biochronology suggests an early Pliocene age. Most of these mammalian taxa were widely distributed over the African continent during the early Pliocene. Possible faunal correlations with eastern African localities call for continent-wide paleontological investigations.***************

New South American record of the Cretaceous–Paleogene boundary interval (La Colonia Formation, Patagonia, Argentina)

The La Colonia Formation is an Upper Cretaceous to Paleogene shallow marine sedimentary unit in Chubut Province (Patagonia), Argentina that preserves important vertebrate and plant fossils. Despite good exposures and significant paleontological investigation, the precise age of the La Colonia Formation and its stratigraphic relationship to the Cretaceous–Paleogene (K–Pg) boundary are not well understood. The K-Pg boundary is associated with one of the largest mass extinctions in Earth's history yet there are few continental stratigraphic records of the boundary in South America, resulting in poor understanding of its effects there. This study combines magnetostratigraphy, detrital zircon uranium–lead (U–Pb) geochronology, and preliminary palynological results to constrain the age of the La Colonia Formation and its fossils more precisely and determine whether it preserves the K–Pg boundary. U–Pb ages of detrital zircons from the directly underlying Puntudo Chico Formation indicate that the base of the La Colonia Formation is younger than ~71.7 Ma. The studied palynological assemblage includes Quadraplanus brossus, which is restricted to the Maastrichtian in other southern hemisphere records. Paleomagnetic results show that the ~125 m Cerro Buitre Norte section of the La Colonia Formation and the overlying Cerro Bororó Formation has dominantly normal polarity except for a ~5 m zone of reversed polarity near the base that is interpreted to correlate to Chron C30R of the Geomagnetic Polarity Timescale (GPTS), and a ~13 m zone of reversed polarity near the top of the La Colonia Formation that is interpreted to correlate to Chron C29R. The presence of a magnetozone correlated to C29R in the La Colonia Formation suggests that it preserves the K–Pg boundary, making it an important target for continued paleontological collection to better understand the K–Pg extinction and recovery dynamics in South America.

Atlantic Geoscience Society Abstracts: 47th Annual Colloquium and General Meeting, February 5 and 6, 2021

Due to current Pandemic circumstances, the 2021 Colloquium &amp; Annual General Meeting was held for the first time using a virtual venue (Zoom) on February 5th and 6th. Although not ideal from the networking and social point of view, not travelling in the unpredictable winter weather of Atlantic Canada was a bonus. On behalf of the society, we thank Colloquium organizers Donnelly Archibald, Rob Raeside, and Chris White, as well the numerous session chairs and judges, for facilitating an excellent meeting with about 200 registrants. AGS acknowledges support from the corporate sponsors and partners for the meeting: Nova Scotia Department of Energy and Mines (Geological Survey and Petroleum Resources), New Brunswick Department Natural Resources and Energy Development, Prospectors &amp; Developers Association of Canada, and Acadia University (Department of Earth and Environmental Science).In the following pages, we are pleased to publish the abstracts of oral and poster presentations from the meeting on a variety of topics. Best undergraduate and graduate student presentations are recognized and indicated by an asterisk in the authorship. The meeting included five special sessions: (1) Defining the controls on onshore and offshore Pliocene-Quaternary processes; (2) Sedimentological and paleontological investigations from the onshore and offshore realms; (3) Developments in geoscience education; (4) Developments in mineral resources research in the northern Appalachians; (5) Karst research in AtlanticCanada; and a general session on mineralogy, igneous and metamorphic geology, and structural geology.Also included with the conference was a day-long, short course on “Applications of GIS (Geographical Information Systems) to Earth Science” delivered by Robin Adair (University of New Brunswick). In addition, a Workshop was held on “Looking to the Future; Equity, Diversity, and Inclusion as a way of being in our discipline” chaired by Anne-Marie Ryan (Dalhousie University) and Deanne van Rooyen (Cape Breton University). The traditional Saturday evening banquet and social were replaced by a virtual Awards Banquet at which society awards were announced, as well as student prizes for best poster and oral presentation. The student award winners are noted at the end of the appropriate abstract.Although the abstracts have been edited as necessary for clarity and to conform to Atlantic Geology format and standards, the journal editors do not take responsibility for their content or quality.

Collapse of Holocene mangrove ecosystems along the coastline of Oman

AbstractSedimentological, geochemical, and paleontological investigations of the coastline of northeastern Oman have provided the authors with an in-depth insight into Holocene sea levels and climate conditions. The spatial distribution and species assemblage of mangrove ecosystems are analyzed. These ecosystems are sensitive to changes in sea level and precipitation and thus reflect ecological conditions. The close proximity to archaeological sites allows us to draw conclusions regarding human interaction with the mangrove ecosystems. Our interdisciplinary inquiry reveals that the mangrove ecosystems along the east coast of Oman collapsed ~6000 cal yr BP on a decadal scale. There is no sedimentological evidence for a mid-Holocene sea-level highstand. The ecosystem collapse was not caused by sea-level variation or anthropogenic interferences; rather, it was the consequence of reduced precipitation values related to a southward shift of the Intertropical Convergence Zone. This resulted in a decrease of freshwater input and an increase in soil salinity. Further, the aridification of the area caused increased deflation and silting up of the lagoons.

A new genus of pliopithecoid from the late Early Miocene of China and its implications for understanding the paleozoogeography of the Pliopithecoidea

A diversity of pliopithecoids is known from Miocene localities in Europe, but until recently, this group was relatively poorly represented in China. However, new discoveries have shown that Chinese pliopithecoids were taxonomically diverse and geographically widespread. The earliest pliopithecoids in China (and Eurasia) are Dionysopithecus and Platodontopithecus from the Early Miocene of Sihong, Jiangsu (∼19−18 Ma). During the Middle Miocene (∼15−12 Ma), several species of pliopithecoids are recorded at localities in Gansu Province (Laogou), Inner Mongolia (Damiao), Xinjiang Uygur Autonomous Region (Tieersihabahe), and Ningxia Hui Autonomous Region (Tongxin). Finally, a late-surviving anapithecine crouzeliid, Laccopithecus robustus, is known from the Late Miocene (∼7 Ma) of Shihuiba in Yunnan, which postdates the extinction of pliopithecoids in Europe (during MN 10). Paleontological investigations at a late Early Miocene locality near Fanchang in Anhui Province have yielded a large sample of isolated teeth (more than one hundred) of a previously unknown species of pliopithecoid. The associated micromammals indicate an age contemporaneous with the Shanwang Formation in Shandong Province (MN 3–4, ∼18−17 Ma). All of the permanent teeth are represented except for I2. With its unique suite of dental features, the Fanchang pliopithecoid can be attributed to a new species and genus. Shared derived features of the lower molars confirm that the Fanchang pliopithecoid has its closest affinities with European crouzeliids, but a number of primitive traits indicate that it is a stem member of the clade. The evidence points to China as an important center for the early diversification of pliopithecoids. Contrary to previous zoogeographic scenarios, the occurrence of an early crouzeliid in China implies that the Pliopithecidae and Crouzeliidae may have diverged from a stem pliopithecoid in Asia during the Early Miocene before their arrival in Europe.

Rare Earth Elements in Dinosaur Bones Across the Embryo-Adult Spectrum

There is broad consensus that many bones of extinct vertebrates contain Rare Earth Elements (REE) and other trace minerals that have been incorporated and enriched into the fossil during diagenesis. During fossilization, apatite minerals in vertebrate bones recrystallize from metastable biogenic forms to thermodynamically more stable inorganic apatite minerals while incorporating REEs from their environment. More than ~95% of the REE in fossil bones are diagenetically incorporated postmortem and bones in different environments have different and distinct REE signatures, generally viewed to be controlled by sedimentological and taphonomic processes. The REE pattern in fossils is generally stable and the normalized concentration patterns provide unique “fingerprints” or signatures that have been used for various geological and paleontological investigations. The discovery of embryos and their adults at the same site, a previously unrecorded occurrence in the fossil record, allowed us to compare for the first time the relationship between REE concentrations in the same taxon at widely differing ontogenetic stages. Here we compare REE patterns in bones from two distinct sites in Yunnan, China, both preserving embryonic and adult bones of Early Jurassic sauropodomorph dinosaurs. These dinosaurs are closely related to each other and close in geological age, and their bones show very similar REE patterns. However, the embryonic bones have significantly lower levels of total REEs when compared to their adult counterparts. We attribute the tenfold difference to the level of ossification of the bones and the dramatically lower concentration of apatites in the embryonic than in the adult bones. We conclude that the ontogenetic stage of fossil materials can have a significant impact on REE concentrations, and discuss the impact of these results on future work.

Holocene paleogeographic evolution of an ancient port city of the central Mediterranean area: Natural and anthropogenic modifications from Salerno city, southern Italy

AbstractA multidiplisciplinary study, including geomorphological, lithostratigraphical, geochronological, geochemical, and paleontological investigations, was carried out in the coastal area of Salerno city, southern Italy. The study aimed to outline the Late Glacial‐Holocene geoenvironmental evolution of Salerno's port area in response to both natural and anthropogenic factors. The geomorphological study included an examination of historic maps, which enabled a detailed reconstruction of the coastal landscape change during historic times. Lithostratigraphical analyses of three new boreholes, supported by radiocarbon and tephrochronological data, and of previously retrieved core‐successions and archaeological trenches, extends our reconstruction of the paleogeographical evolution of the Salerno coastal area back to the Late Pleistocene. Geochemical and paleontological analyses of samples from the newly acquired cores were combined with the lithofacies analyses of previously retrieved cores to detect ancient harbors in the area of the current port facilities of the city and surrounding urban areas. This work contributes to scientific debate about the specific sedimentary architectures and geochemical properties of the Salerno harbor environment and refines methodological approaches for characterizing and assessing the evolution and demise of ancient port facilities in Mediterranean coastal cities.

Geological record of prehistoric tsunamis in Mugi town, facing the Nankai Trough, western Japan

Stratigraphic and paleontological investigations in Mugi Town, on the Pacific coast of Shikoku Island, revealed evidence of as many as five tsunami inundations from events along the Nankai Trough between 5581 and 3640 cal yr BP. Nine event deposits (E1–E9) were identified in cores ranging in length from 2 to 6 m, consisting of sandy and gravelly layers interbedded with organic-rich mud. Sedimentary structures in the event deposits observed by computed tomography included normal grading and sharp lower stratigraphic contacts. Event deposits E3, E6, E7, and E8 contained mainly brackish-marine diatom species, suggesting that they had been deposited during inundation by seawater. In addition, fossil diatom assemblages were markedly different above and below event deposits E3, E4, E6, and E8. For example, assemblages below event deposit E6 were dominated by a freshwater species (Ulnaria acus), whereas assemblages above it were predominantly brackish-marine (Diploneis smithii, Fallacia forcipata, and Fallacia tenera). We attributed these changes to the increase of marine influence due to coastal subsidence associated with subduction-zone earthquakes, as documented in the 1946 Showa-Nankai earthquakes. We conclude that event deposits E3, E6, and E8 and perhaps E4 and E7 were deposited by tsunamis generated by subduction zone earthquakes along the Nankai Trough. The ages of these event deposits, as constrained by ten radiocarbon ages, suggest that some of the tsunamis that impacted Mugi Town were correlated with those reported elsewhere along the Nankai Trough, thereby complementing the existing but still incomplete geological record for these events.

Ordovician strata in the Cliefden Caves area, New South Wales: a case study in the preservation of a globally significant paleontological site

The Cliefden Caves area in central-western New South Wales includes the scientifically most important and irreplaceable examples of fossiliferous Ordovician rocks in the State. Exposures of the stratigraphically lower parts of the Cliefden Caves Limestone Subgroup on the aptly named Fossil Hill are world-famous among paleontologists and internationally significant for preserving the earliest in situ shell beds documented in the literature. They also contain some of the oldest known rugose corals, and an exceptional example of one of the oldest coralline biostromes, as well as many examples of invertebrate fossils and cyanobacterial mat structures that either are unique to this locality or were first described from here. Other stratigraphic levels throughout the total 363 m-thick Cliefden Caves Limestone Subgroup are similarly endowed with highly significant fossils, such as a globally unique in situ shell bank with rare examples of the trimerellide brachiopod Belubula spectacula, a wealth of shelly fossils and trilobites on Dunhill Bluff (adjacent to Fossil Hill to the east), and the appropriately named Trilobite Hill. Less well known to the general public, but of international importance to paleontologists, is the unique deep-water sponge fauna of the overlying Malongulli Formation that occurs at several levels in limestone lenses within this unit. Fossils from the Cliefden Caves Limestone Subgroup and the Malongulli Formation have been documented in more than 60 scientific papers and monographs since paleontological investigations into the site were first published in 1895. Despite concerted scientific endeavour in the region over the past 50 years, much more study needs to be done to fully document the paleontological riches of the Cliefden Caves area. These sites are interpreted as the remains of a tropical island, fringed by limestone and flanked by deep-water environments in which the Malongulli Formation was deposited. Preservation of such islands is exceptionally rare in the geological record. It is therefore vital for the area to remain accessible to scientific researchers to continue their studies. Flooding of the Belubula Valley by a proposed dam downstream from the Cliefden Caves area would hinder future research work on this unique geoheritage resource. Fortunately, a successful public campaign has led to listing of the site on the State Heritage Register that will provide essential protection of the caves from inundation while ensuring continued access to researchers.

The Carnivores of Quarry 3, Agate Fossil Beds National Monument

At the beginning of the twentieth century, in the remote upper reaches of the Niobrara River valley, paleontologists discovered an unbelievable trove of fossil bones eroding from two adjacent hillsides. Under these two “fossil hills” were buried entire skeletons of extinct animals that previously had been known only by fragmentary remains. Over the next two decades, leading museums of the day expended great effort exposing and then extracting whole portions of this bonebed for public exhibition and for research purposes. Many years later, scientists from the University of Nebraska–Lincoln reopened the old quarries to search for clues, long overlooked, that might explain why rhinoceroses, chalicotheres, and entelodonts had perished together millions of years ago at this particular place. In the process, they uncovered carnivore dens unrecognized by the first excavators. Today, the displays at Agate Fossil Beds National Monument lead visitors through the forensic evidence that discloses a sequence of events culminating in the demise of many hundreds of animals. The exhibits at the visitor center also include murals by artist Mark Marcuson and a diorama that uses full skeletal mounts, all illustrating the fascinating story of the Agate bonebed. In addition, the park is situated in a 3,000-acre preserve of shortgrass prairie and tells the story of rancher James Cook, who first noticed the bones in the 1880s, and his friendship with the scientists who came to excavate at Agate. Visitors can follow several trails to view the historic fossil sites, where wayside exhibits explain the paleontological investigations, and reconstruct the landscape of a dryland paleoriver valley and its animals, 22 million to 23 million years ago.

Environmental reconstruction spanning the transition from hunter/gatherers to early farmers in Colombia: paleopedological and archaeological indicators from the pre-ceramic sites Tequendama and Aguazuque

Complex geoarchaeological research of the archaeological sites with continuous long-term occupation could provide insight into environmental change and human-landscape interaction during the transition from hunter-gatherer to horticulture economy in the north-west of South America. We performed a paleopedological study in the new sections at Tequendama (rockshelter site) and Aguazuque (open-air site) two key pre-ceramic sites of the Savannah of Bogotá region of Colombia, combined with traditional archaeological and paleontological investigations. The chronological scales of the sections based on a large number of 14C dates show that their occupation periods are complementary and together cover the period from the terminal Pleistocene to late Holocene. The material of the archaeological layers has a colluvial origin with large tephra input. Presence of volcanic components influence pedogenesis supporting development of granular structure, dark humus accumulation, and Andic properties that could not be used for paleoenvironmental reconstruction. Micromorphological observations however show abundant evidence of pedogenic carbonate accumulation that we interpret as evidence of gradual aridization during the middle Holocene. This conclusion is supported by the paleontological data, an upward increase of the frequency of Cavia sp. remains, and agrees with the regional palynological proxies. Aridization was the background environmental trend during the transition period from a hunter-gatherer economy to an early horticulture and plant and animal domestication.

The Konservat-Lagerstatte Menat (Paleocene; France) - an overview and new insights

The Konservat-Lagerstatte Menat (Puy-de-Dome, France) is an outstanding archive of a Paleocene ecosystem, which was deposited in a former maar lake. Excavations during the last century have yielded an extensive flora and fauna record, therefore an overview of the current state of paleontological investigations is given in this paper. Additionally, new results based on excavations from the years 2012 to 2014 are presented. The preservation of organic matter differed strongly between excavation sites, probably influenced by weathering processes. The stratigraphic succession consists mostly of organic-rich clays, intercalated with hard, silicified claystones. In 2013 and 2014 both impression and compression fossils were collected from different outcrops. Compression fossils from organic-rich clays were exceptionally well-preserved and included three-dimensional plant remains. A new database on insect paleobiodiversity was compiled. The occurrence of charcoal in almost all horizons investigated suggests that paleowildfires were frequent during the Paleocene in the vicinity of the paleolake. The results confirm the high potential of the Konservat-Lagerstatte Menat for future paleontological research.

Extending the paleontology-biogeography reciprocity with SDMs: Exploring models and data in reducing fossil taxonomic uncertainty.

Historically, studies aimed at prospecting and analyzing paleontological and neontological data to investigate species distribution have developed separately. Research at the interface between paleontology and biogeography has shown a unidirectional bias, mostly focusing on how paleontological information can aid biogeography to understand species distribution through time. However, the modern suit of techniques of ecological biogeography, particularly species distribution models (SDM), can be instrumental for paleontologists as well, improving the biogeography-paleontology interchange. In this study, we explore how to use paleoclimatic data and SDMs to support paleontological investigation regarding reduction of taxonomic uncertainty. Employing current data from two neotropical species (Lagostomus maximus and Myocastor coipus), we implemented SDMs and performed model validation comparing hindcasts with dated fossil occurrences (~14k and ~20k years back present, respectively). Finally, we employed the hindcasting process for two South American fossil records of a misidentified species of caiman (Caiman sp.) to show that C. latirostris is the most likely species identity of these fossils (among four candidate species: C. latirostris, C. yacare, C. crocodilus, and Melanosuchus niger). Possible limitations of the approach are discussed. With this strategy, we have shown that current developments in biogeography research can favour paleontology, extending the (biased) current interchange between these two scientific disciplines.