Preprints
Filtering by Subject: Paleontology
Author citation metrics in paleontology: the h-index and the c-score
Published: 2025-10-07
Subjects: Paleontology
The so-called “Stanford ranking” (SR) of standardized citation indicators is based on the calculation of an individual scientist’s c-score, a composite index that addresses the main shortcomings of the h-index. This ranking is updated annually and includes the top 100000 ranked scientists, as well as those within the top 2% in each specialty. This paper focuses on the 500 paleontologists featured [...]
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 [...]
Out of Afar: the first hominin migration? Long-term landscape changes in the Afar region and implications for hominin bipedalism
Published: 2025-07-18
Subjects: Paleontology
Climate change in Africa has long been considered to be a key driver in hominin behavioural adaptations such as bipedalism. The prevailing argument holds that open grasslands favoured the adoption of bipedalism, which can be defined as one of three types: facultative, habitual, and obligate. Across Africa, only one region, Ethiopia, shows evidence of hominins showing all three types of [...]
Continental-Scale Carbonate Sedimentation and Environmental Correlates of the Shuram-Wonoka Excursion
Published: 2025-07-01
Subjects: Biogeochemistry, Earth Sciences, Geochemistry, Geology, Paleontology, Physical Sciences and Mathematics, Sedimentology, Stratigraphy
Strata of the Ediacaran Period record many Earth-Life features that distinguish the Neoproterozoic-Phanerozoic transition. However, it is difficult to determine cause and effect relationships between Ediacaran events. Continental-scale patterns of sedimentation have been used as proxies to investigate controls on Phanerozoic macroevolution, including sea level drivers and potential carbon cycling [...]
Weakening of AMOC linked to past Greenland Ice Sheet retreat
Published: 2025-03-21
Subjects: Atmospheric Sciences, Climate, Earth Sciences, Geochemistry, Geology, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Paleontology, Physical Sciences and Mathematics
A weakening of the Atlantic Meridional Overturning Circulation (AMOC) is predicted to occur under multiple scenarios of future warming. However, the effect of meltwater from a decaying Greenland Ice Sheet (GrIS) on AMOC is uncertain. Using a basin-wide network of North Atlantic sediment cores, we show that the largescale melting of the GrIS during a previous interglacial (Marine Isotope Stage 11c [...]
Ediacaran coupling of climate and biosphere dynamics
Published: 2025-03-14
Subjects: Climate, Glaciology, Paleontology, Sedimentology, Stratigraphy
Throughout the Phanerozoic (538.8 Ma to present), climate change is demonstrably linked to radiations, extinctions, and turnovers in the biosphere. Here, we show that this connection existed in the late Ediacaran (~579 to 538.8 Ma), the first interval in Earth’s history to host complex macro-organisms, including early metazoans. Current correlations of glacial sedimentary deposits have been used [...]
A comment on the indicator capacity of Artemisia pollen in pre-Holocene paleoecology
Published: 2025-03-07
Subjects: Paleontology
In pre-Holocene paleoecology, Artemisia (Asteraceae) pollen is commonly considered an indicator of arid steppic environments in temperate regions. However, the >520 known species of this genus occur across a wide range of bioclimatic conditions. This paper comments on a recent comprehensive study that examined the identification of Artemisia pollen at the species level in relation to the [...]
Drastic Changes in Atmospheric CO2 Concentration Led to Biological Mass Extinction and Explosion
Published: 2025-03-07
Subjects: Earth Sciences, Environmental Sciences, Paleontology
When the area of polar ice caps expands to a certain threshold, a positive feedback effect will occur. Due to the strong reflection of sunlight by ice and snow, the global climate will become cold and dry. CO₂ in the atmosphere will be rapidly sequestered in the seabed and permafrost through the biological carbon pump, thereby affecting plant photosynthesis, reducing NPP and the nutritional value [...]
Middle Miocene Mediterranean mangroves and potential modern analogs
Published: 2025-02-24
Subjects: Paleontology
During the Miocene Climatic Optimum (MCO; 17–15 Ma), the northern boundary of mangroves – now situated at ~30° N – extended along the northern Mediterranean coasts (~45° N). These Avicennia-only mangroves have been considered impoverished mangroves controlled by the general latitudinal temperature gradient. The MCO Mediterranean mangroves have been compared with the extant Middle East (ME) [...]
The Role of Quaternary Spatiotemporal Gradients and Dynamic Disequilibrium in Shaping Present Neotropical Biotic Patterns
Published: 2025-02-11
Subjects: Paleontology
No abstract available
Where has all the Sinter gone? From the Pink and White Terraces, the Greatest Tourist Attraction of the Southern Hemisphere
Published: 2025-02-02
Subjects: Environmental Studies, Geology, Geomorphology, Other Geography, Paleontology, Physical and Environmental Geography, Spatial Science, Stratigraphy, Volcanology
Debate continues over the silica sinter Pink and White Terraces, the greatest tourist attraction of the southern hemisphere. The 1886 Tarawera eruption may or may not have destroyed them by burial or eruption. This research compiles surviving sinter. The volume is unexpectedly tiny, which bears on the debate. A database was developed including photography. A forensic approach was taken to [...]
A critical evaluation of fossil pollen records from the mangrove tree Pelliciera beyond the Neotropics: biogeographical and evolutionary implications
Published: 2024-12-13
Subjects: Paleontology
Pelliciera is a Neotropical mangrove tree restricted to a small region around the Panama Isthmus. In the past, this taxon was distributed across much of the Neotropics, reaching its maximum extent during the Oligo-Miocene. The occurrence of Pelliciera outside the Neotropics had been debated based on a few fossil pollen records from Africa and Europe, though many of these records have been [...]
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 [...]
Discussion of Košťák et al. (2021), Fossil evidence for vampire squid inhabiting oxygen-depleted ocean zones since at least the Oligocene.
Published: 2024-10-23
Subjects: Geology, Paleontology
Košťák et al. (2021) is important in presenting the first known Cenozoic fossil of a vampyromorph. Some modifications to the interpretations are needed, however. The first concerns inferring water depth habitat of non-benthic animals from fossils found in deep water sediments. The second concerns the water depth estimates for the La Voulte-sur-Rhône exceptionally preserved biota (La Voulte EPB), [...]
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 [...]