Preprints
Filtering by Subject: Paleobiology
Forest or tundra? How different vegetation reconstructions of Last Glacial landscapes in Europe may shape our perception of early human dispersal processes
Published: 2026-05-08
Subjects: Earth Sciences, Geography, Human Geography, Nature and Society Relations, Paleobiology, Paleontology, Physical and Environmental Geography
Regional variability and long-term changes of past ecosystems likely had a strong impact on hunter-gatherer population dynamics, including the expansion of anatomically modern humans and the disappearance of Neanderthals. However, our understanding of these ecosystems remains limited, even when looking at large-scale patterns, such as the extent and distribution of forested areas. Vegetation [...]
Reduced geomagnetic shielding increased UV-B radiation at Earth’s surface during the Laschamps Event
Published: 2026-05-01
Subjects: Astrophysics and Astronomy, Atmospheric Sciences, Biochemistry, Biogeochemistry, Biology, Earth Sciences, Ecology and Evolutionary Biology, Environmental Chemistry, Environmental Sciences, Geology, Geophysics and Seismology, Life Sciences, Oceanography and Atmospheric Sciences and Meteorology, Other Life Sciences, Paleobiology, Physical and Environmental Geography, Physical Sciences and Mathematics, Planetary Geochemistry, Planetary Geology, Planetary Geophysics and Seismology, Planetary Sciences, Social and Behavioral Sciences, Statistics and Probability
Exposure to excess UV-B radiation can harm organisms through DNA damage and oxidative stress, and has likely been a key ecological and evolutionary driver throughout Earth’s history. Here, we show UV-B at Earth’s surface was significantly increased during the Laschamps Event, the last major geomagnetic excursion ca. 41ka BP. During the Laschamps, we find significant and prolonged (lasting [...]
Agent-based Modelling of Microbialite Formation through Sedimentation and Precipitation Dynamics
Published: 2026-04-13
Subjects: Biogeochemistry, Earth Sciences, Geochemistry, Other Earth Sciences, Paleobiology, Paleontology, Physical Sciences and Mathematics, Sedimentology, Stratigraphy
Fossil microbialites resulting from the interplay of sedimentation and microbially induced precipitation are among the oldest evidence of life on Earth and help geobiologists interpret many sedimentary environments. However, the factors governing their internal structure and external morphology are still poorly understood. Additionally, abiotic processes can mimic the morphology of some [...]
Stable isotopic composition, paleoecology, and habitat of the ammonite Sphenodiscus lobatus in the Late Cretaceous (Maastrichtian) Western Interior Seaway
Published: 2026-03-04
Subjects: Earth Sciences, Geochemistry, Paleobiology, Paleontology, Sedimentology
Despite their abundance as fossils, the life histories of ammonites are still poorly understood. We analyzed the oxygen (δ18O) and carbon (δ13C) isotopic composition of well-preserved shell material taken from different growth stages of the streamlined oxyconic ammonite species Sphenodiscus lobatus from the Upper Cretaceous (Maastrichtian) Pierre Shale and Fox Hills Formation of South Dakota. [...]
ForamJ – A Tool for the Reproducible, Semi-automated Analysis of Foraminifera Micro Computed Tomography Datasets
Published: 2026-01-11
Subjects: Paleobiology, Paleontology, Research Methods in Life Sciences
The application of micro-computed tomography (µCT) to foraminiferal test analysis has opened new avenues for high-resolution, non-destructive 3D characterisation of internal and external morphological features. However, existing workflows are typically limited by low throughput, manual segmentation, and reliance on proprietary software, constraining dataset reproducibility and scalability. Here [...]
Hidden in plain sight? Some challenges and needs for practical planetary biosignature exploration, both home and away-A Mini-Review.
Published: 2025-11-01
Subjects: Biogeochemistry, Other Earth Sciences, Other Planetary Sciences, Paleobiology, Planetary Biogeochemistry, Planetary Geochemistry
Identifying organic molecular biosignatures for life is challenging. Most current analytical methods were developed on Earth sediments rich in total organic carbon (TOC), and these methods struggle when dilute organic matter is situated within reactive, mineralogically complex astrobiological samples. Diverse geological alteration processes degrade biomarker signals, often concealing some [...]
Eocene lacustrine–volcaniclastic deposits at Aliabad (Central Iran): A possible Proto-basin of the Oligo-Miocene Qom Formation
Published: 2025-10-14
Subjects: Earth Sciences, Geology, Paleobiology, Paleontology, Physical Sciences and Mathematics, Sedimentology, Stratigraphy, Volcanology
Central Iran hosts intricate Cenozoic successions where the Oligo‑Miocene Qom Formation forms a major hydrocarbon reservoir. The stratigraphic and paleoenvironmental relationship of the Eocene Aliabad deposits to this formation has been controversial. This study integrates stratigraphic logging, petrography, geochemistry (XRD/XRF), and ichnology on 46 thin sections from Aliabad and 157 [...]
Unraveling Southern Ocean Diatom Diversity Across the Eocene/Oligocene Transition
Published: 2025-09-09
Subjects: Biodiversity, Earth Sciences, Paleobiology, Paleontology
The Eocene-Oligocene transition (EOT) was a critical interval of global cooling and circulation change that reshaped marine ecosystems. However, current knowledge of diatom diversity and community dynamics during this interval relies mainly on biostratigraphic compilations, which largely document common species and thus likely underestimate true diversity. This study provides a more complete [...]
Algal lipid distributions and hydrogen isotope ratios reflect phytoplankton community dynamics
Published: 2025-01-20
Subjects: Earth Sciences, Geochemistry, Paleobiology, Physical Sciences and Mathematics, Sedimentology
Reconstructions of past changes in algal community composition provide important context for future alterations in biogeochemical cycling. However, many existing phytoplankton proxies are indicative of individual algal groups and are not fully representative of the whole community. Here, we evaluated hydrogen isotope ratios of algal lipids (δ2HLipid) as a potential proxy for phytoplankton [...]
Disappearance of Homo floresiensis from Liang Bua alongside seasonal aridification of Flores 61,000-47,000 years ago
Published: 2024-12-10
Subjects: Atmospheric Sciences, Climate, Environmental Indicators and Impact Assessment, Fresh Water Studies, Geochemistry, Hydrology, Paleobiology, Physical Sciences and Mathematics, Speleology
The cause of the disappearance of the primitive hominin, Homo floresiensis, from the Indonesian island of Flores ~50,000 years ago is a key question in palaeoanthropology. The potential roles of human agency and climate change continue to be debated, but the history of freshwater availability critical to survival at the type locality, Liang Bua, remains unknown. Although speleothem 18O is used [...]
Miocene ant-mealybug trophobiosis imaged with X-Ray micro-computed tomography
Published: 2024-10-26
Subjects: Paleobiology, Paleontology, Research Methods in Life Sciences
Amber is a remarkable preserving medium for Mesozoic and Cenozoic terrestrial biotas, but even when transparency is good, available viewing angles can be limited. The technique of X-ray micro-computed tomography allows inspection from any desired viewpoint and facilitates detailed anatomical measurements, avoiding parallax errors. Here, I show the use of this technique to study an extremely rare [...]
deeptime: an R package that facilitates highly customizable and reproducible visualizations of data over geological time intervals
Published: 2024-10-17
Subjects: Earth Sciences, Geology, Paleobiology, Paleontology, Stratigraphy
Data visualization is a key component of any scientific data analysis workflow and is vital for the summarization and dissemination of complex ideas and results. One common hurdle across the Geosciences and other scientific fields remains the reproducibility of many types of visualizations of data over long time intervals (104+ years). Here I introduce the R package deeptime, which provides [...]
Taphonomic Controls on a Multi-Element Skeletal Fossil Record
Published: 2024-08-02
Subjects: Earth Sciences, Life Sciences, Paleobiology, Paleontology, Physical Sciences and Mathematics, Sedimentology
Animals with multi-element skeletons, including the vertebrates, echinoderms, and arthropods, are some of the most biodiverse and ecologically important animal groups. Understanding the relative impact of the myriad geological and biological factors which impact on the quality of multi-element skeletal fossils is thus crucial for disentangling perceived changes in biodiversity through time and [...]
The potential of terrestrial and aquatic molluscs for the temporal analysis of Deckenschotter deposits and younger Quaternary sediments from the Swiss Plateau
Published: 2024-05-02
Subjects: Earth Sciences, Geology, Geomorphology, Paleobiology, Paleontology, Physical Sciences and Mathematics, Sedimentology, Soil Science, Stratigraphy, Terrestrial and Aquatic Ecology
Pleistocene shifts in Great Basin hydroclimate seasonality govern the formation of lithium-rich paleolake deposits
Published: 2024-04-10
Subjects: Earth Sciences, Hydrology, Oceanography and Atmospheric Sciences and Meteorology, Paleobiology, Sedimentology
Southwestern North America is currently experiencing a multidecadal megadrought, with severe consequences for water resources. However, significant uncertainty remains about how precipitation will change in the 21st century in this semi-arid region. Paleoclimatic records are essential for both contextualizing current change, and for helping constrain the sensitivity of regional hydroclimate to [...]