SEARCH · Search bioRxiv

Results for “paleontology”

Search indexed bioRxiv preprints in genomics, neuroscience, cell biology and bioinformatics. Read source abstracts and check manuscript versions; preprints are not peer reviewed.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 109 records · Page 6Linked to original sources

bioRxiv2019

Tracking human population structure through time from whole genome sequences

The genetic diversity of humans, like many species, has been shaped by a complex pattern of population separations followed by isolation and subsequent admixture. This pattern, reaching at least as far back as the appearance of our species in the paleontological record, has left its traces in our genomes. Reconstructing a populations history from these traces is a challenging problem. Here we present a novel approach based on the Multiple Sequentially Markovian Coalescent (MSMC) to analyse the population separation history. Our approach, called MSMC-IM, uses an improved implementation of the MSMC (MSMC2) to estimate coalescence rates within and across pairs of populations, and then fits a continuous Isolation-Migration model to these rates to obtain a time-dependent estimate of gene flow. We show, using simulations, that our method can identify complex demographic scenarios involving post-split admixture or archaic introgression. We apply MSMC-IM to whole genome sequences from 15 worldwide populations, tracking the process of human genetic diversification. We detect traces of extremely deep ancestry between some African populations, with around 1% of ancestry dating to divergences older than a million years ago.\n\nAuthor SummaryHuman demographic history is reflected in specific patterns of shared mutations between the genomes from different populations. Here we aim to unravel this pattern to infer population structure through time with a new approach, called MSMC-IM. Based on estimates of coalescence rates within and across populations, MSMC-IM fits a time-dependent migration model to the pairwise rate of coalescences. We implemented this approach as an extension to existing software (MSMC2), and tested it with simulations exhibiting different histories of admixture and gene flow. We then applied it to the genomes from 15 worldwide populations to reveal their pairwise separation history ranging from a few thousand up to several million years ago. Among other results, we find evidence for remarkably deep population structure in some African population pairs, suggesting that deep ancestry dating to one million years ago and older is still present in human populations in small amounts today.

evolutionary biology↗

bioRxiv2019

Museum epigenomics: characterizing cytosine methylation in historic museum specimens

Museum genomics has transformed the field of collections-based research, opening up a range of new research directions for paleontological specimens as well as natural history specimens collected over the past few centuries. Recent work demonstrates that it is possible to characterize epigenetic markers such as DNA methylation in well-preserved ancient tissues. This approach has not yet been tested in traditionally-prepared natural history specimens such as dried bones and skins, the most common specimen types in vertebrate collections. In this study, we develop and test methods to characterize cytosine methylation in dried skulls up to 76 years old. Using a combination of ddRAD and bisulfite treatment, we characterized patterns of cytosine methylation in two species of deer mouse (Peromyscus spp.) collected in the same region in Michigan in 1940, 2003, and 2013-2016. We successfully estimated methylation in specimens of all age groups, though older specimens yielded less data and showed greater interindividual variation in data yield than newer specimens. Global methylation estimates were reduced in the oldest specimens (76 years old) relative to the newest specimens (1-3 years old), which may reflect post mortem hydrolytic deamination. Methylation was reduced in promoter regions relative to gene bodies and showed greater bimodality in autosomes relative to female X chromosomes, consistent with expectations for methylation in mammalian somatic cells. Our work demonstrates the utility of historic specimens for methylation analyses, as with genomic analyses; however, such studies will need to accommodate the large variance in the quantity of data produced by older specimens.

genomics↗

bioRxiv2025

Claws that snap: the raptorial mechanism of dryinid wasps

Prey capture is a key selection pressure, often favoring extreme performance morphologies. Many mechanisms of prey capture, however, remain poorly understood. In this study, we document the remarkable raptorial behavior and evolutionary biomechanics of the "pincer wasps" (Hymenoptera: Dryinidae). Dryinid claws, previously thought to function as simple vises (Nachtigall-&-Nachtigall-1974), are shown to possess "snap traps", or claws that close rapidly upon prey contact. Detailed morphological analysis, using synchrotron-radiation microtomography (SR-{micro}-CT), reveals that all long-clawed dryinids can overcenter their specialized anterior pretarsal claws, presumably allowing elastic energy storage in the pretarsal apodemes. Uniquely, explosive release of this energy, leading to claw closure, appears to occur not through active withdrawal of a latch, but as the direct consequence of contact with the prey: impact hyperextends a specialized trigger-joint complex of the tarsus, pulling the claw back into undercenter alignment, and so freeing the stretched apodeme to fully recoil. Such a "contact trigger" is eminently useful, as these trap-claw wasps prey on insects with explosive jump capacity; by linking trap shutting with prey contact, success chances are increased. Paleontological and allometric analyses suggest that the raptorial behavior likely preceded the evolution of overcentering, which appears to have evolved via release from developmental constraint on anteroposterior symmetry, leading to a distinct scaling rule. These findings expand the documented diversity of spring-loaded biological mechanisms and establish Dryinidae as a promising system for studying how developmental constraints, mechanical demands, and functional innovation shape ecomorphological diversity. HIGHLIGHTSO_LIDryinidae catch prey with spring-loaded trap claws, relying on a unique direct-action trigger. C_LIO_LIRaptorial behavior evolved first, followed by the functional derivation of two separate components. C_LIO_LIThe evolution of novel raptorial mechanism was enabled by release of ancestral developmental constraint. C_LI

evolutionary biology↗

bioRxiv2026

Quantifying biomarker ambiguity using metabolic network analysis

Molecular biomarkers preserved in rocks provide evidence about ancient life but interpreting them requires inference through multiple stages of information loss arising from phylogenetic, biosynthetic, and diagenetic ambiguity. However, biomarker specificity is typically assessed qualitatively rather than quantitatively. Here we formalize biosynthetic ambiguity as entropy over metabolic networks. We introduce three metrics that quantify pathway-level information content: retrobiosynthetic complexity ({psi}), normalized branch depth ({lambda}), and fraction shared ({sigma}). Analysis of 9,140 MetaCyc metabolites defines a three-dimensional specificity space for biomarker evaluation. Only 13% of multi-pathway compounds exhibited low complexity, distal divergence, and high pathway consensus. Lipid biomarkers span this specificity space heterogeneously: hopanoids cluster near the high-specificity region while sterols occupy intermediate territory. Diagnostic quality and lipophilicity are approximately independent, so the constraint on molecular paleontology is the limited chemical diversity among preservable compound classes rather than their biosynthetic properties. This framework supports probabilistic biomarker interpretation by explicitly incorporating biosynthetic, phylogenetic, and diagenetic constraints.

bioinformatics↗

bioRxiv2026

TaxonMatch: taxonomic integration and tree construction from heterogeneous biological databases

Integrating taxonomic data across heterogeneous biological databases remains a major challenge in biodiversity research due to non-standardized nomenclature, incomplete synonym annotation, and inconsistencies in taxonomic hierarchies. These issues limit interoperability between key resources such as the Global Biodiversity Information Facility (GBIF), the National Center for Biotechnology Information (NCBI), and citizen science platforms such as iNaturalist. Here, we present TaxonMatch, a scalable and reproducible framework for taxonomic reconciliation and cross-database integration. The workflow combines string-based candidate generation using TF-IDF vectorization, supervised machine learning for match classification, and lineage-aware synonym resolution to align taxonomic entities across multiple sources. By integrating both declared and implicit equivalences, TaxonMatch resolves typographical variation, synonymy, and structural inconsistencies in taxonomic data. The framework produces a unified taxonomic structure in which equivalent entities are reconciled while preserving source-specific identifiers, provenance information, and hierarchical relationships. We evaluate its robustness across multiple classifiers and demonstrate its effectiveness in resolving ambiguous taxonomic cases that are not handled by traditional matching approaches. We illustrate the applicability of TaxonMatch through three use cases: the construction of a unified arthropod taxonomy integrating GBIF, NCBI, and iNaturalist data; the identification of closest extant relatives of fossil taxa with molecular information; and the integration of genomic resources with conservation data from the IUCN Red List. These applications highlight the ability of the workflow to support the integration of ecological, genomic, and paleontological datasets. TaxonMatch provides a flexible and generalizable solution for taxonomic data integration, enabling the construction of coherent and interoperable biodiversity datasets for downstream analyses in ecology, evolution, and conservation biology.

evolutionary biology↗

bioRxiv2026

Display functions of dinosaur proto-wings before powered flight

Pennaceous feathers are fundamental to avian flight, yet their early function in non-volant dinosaurs remains unknown. Early-diverging pennaraptorans had simple pennaceous feathers on proto-wings and tails, which were unsuitable for flight but may have enhanced visual signals. However, the visual display hypothesis has not been empirically tested. To address this, we used computer animations of early pennaraptoran displays to measure responses in a well-established animal model of a visually sensitive neural pathway. We show that pennaceous proto-wings and tails enhance the efficiency of motion-based displays across a range of anatomically plausible movements. Integrating these results with comparative and paleontological evidence, we suggest that early pennaceous feathers functioned in diverse signaling contexts and were subsequently exapted for aerodynamic use.

evolutionary biology↗

bioRxiv2026

DeMoDa: A global open access database for comparative research in human dental morphological variation

Human dental morphology is diverse and varies both within and between populations worldwide. Common variants include different numbers of cusps and roots, as well as different configurations in the fissures, ridges, and grooves on tooth crowns. Because teeth preserve well in taphonomic contexts and retain strong genetic signatures in their morphology, researchers across disciplines use dental form for research ranging from population affinity identification in forensic cases to the reconstruction of population history in archaeological and paleontological studies, and to explore the genetic underpinnings of dental development. However, these analyses are limited, as no publicly available comprehensive database of human dental morphological variation currently exists. Data are typically shared only within professional networks, excluding scientists outside those circles. Information is dispersed across repositories and the supplementary materials that accompany peer-reviewed publications, creating a fragmented and difficult-to-navigate data landscape. Although numberous dental anthropologists devoted their careers to collecting extensive datasets from thousands of individuals worldwide, their data have not yet been published in raw form nor made compatible. Here, we introduce the Dental Morphological Database (DeMoDa), an open access repository comprising 246 dental traits for 17,308 individuals across 32 major geographic regions worldwide spanning the past several thousand years. These data are from the legacy datasets of Turner, Hanihara, Scott, and Irish. Because these researchers used different scoring systems, we developed a scoring system with two steps that enables the three most-common scoring systems to be combined. We provide two versions of the data that correspond to these two steps: one with more nuanced trait scores at the cost of a smaller sample size, and another with less nuanced trait scores but broader sample coverage. We discuss the implications of publishing these legacy data and outline our decision-making process that guided their release in accordance with both the FAIR and CARE principles of open science.

evolutionary biology↗

bioRxiv2014

Osmunda pulchella sp. nov. from the Jurassic of Swedenreconciling molecular and fossil evidence in the phylogeny of Osmundaceae

The systematic classification of Osmundaceae has long remained controversial. Recent molecular data indicate that Osmunda is paraphyletic, and needs to be separated into Osmundastrum and Osmunda s. str. Here we describe an exquisitely preserved Jurassic Osmunda rhizome (O. pulchella sp. nov.) that combines diagnostic features of Osmundastrum and Osmunda, calling molecular evidence for paraphyly into question. We assembled a new morphological matrix based on rhizome anatomy, and used network analyses to establish phylogenetic relationships between fossil and extant members of modern Osmundaceae. We re-analysed the original molecular data to evaluate root-placement support. Finally, we integrated morphological and molecular data-sets using the evolutionary placement algorithm. Osmunda pulchella and five additional, newly identified Jurassic Osmunda species show anatomical character suites intermediate between Osmundastrum and Osmunda. Molecular evidence for paraphyly is ambiguous: a previously unrecognized signal from spacer sequences favours an alternative root placement that would resolve Osmunda s.l. as monophyletic. Our evolutionary placement analysis identifies fossil species as ancestral members of modern genera and subgenera. Altogether, the seemingly conflicting evidence from morphological, anatomical, molecular, and palaeontological data can be elegantly reconciled under the assumption that Osmunda is indeed monophyletic; the recently proposed root-placement in Osmundaceae--based solely on molecular data--likely results from un- or misinformative out-group signals.

Paleontology↗

bioRxiv2015

Community stability and selective extinction during Earth’s greatest mass extinction

We modelled the resilience and transient dynamics of terrestrial paleocommunities from the Karoo Basin, South Africa, around the Permian-Triassic mass extinction. Using recently refined biostratigraphic data that suggest two pulses of extinction leading up to the Permian-Triassic boundary, we show that during times of low extinction, paleocommunities were no more stable than randomly assembled communities, but they became stable during the mass extinction. Modelled food webs before and after the mass extinction have lower resilience and less stable transient dynamics compared to random food webs lacking in functional structure but of equal species richness. They are, however, more stable than random food webs of equal richness but with randomized functional structure. In contrast, models become increasingly more resilient and have more stable transient dynamics, relative to the random models, as the mass extinction progressed. The increased stability of the community that resulted from the first pulse of extinction was driven by significant selective extinction against small-bodied amniotes, and significantly greater probabilities of survival of large-bodied amniotes. These results point to a positive relationship between evolved patterns of functional diversity and emergent community dynamics, with observed patterns being more stable than alternative possibilities.\n\nSignificanceAnthropogenic impacts on modern ecosystems have no precedents in human history. The fossil record does contain episodes of severe biodiversity crises, but incomplete preservation and low temporal resolution make it difficult to equate fossil data to modern ecological processes. We examined terrestrial paleocommunities from Earths most severe mass extinction, the Permian-Triassic mass extinction (PTME), and modelled their dynamic stabilities. We show that during times of low extinction, paleocommunities were no more stable than randomly assembled communities, but they became more stable during the mass extinction. Increased stability resulted mostly from selective extinction and survival based on vertebrate body size. Whether modern communities will behave similarly depends on the similarity between human drivers and those of the PTME.

Paleontology↗

bioRxiv2015

Fables and foibles: a critical analysis of the Palaeoflora database and the Coexistence approach for palaeoclimate reconstruction

The \"Coexistence Approach\" is a mutual climate range (MCR) technique combined with the nearest-living relative (NLR) concept. It has been widely used for palaeoclimate reconstructions based on Eurasian plant fossil assemblages, most of them palynofloras (studied using light microscopy). The results have been surprisingly uniform, typically converging to subtropical, per-humid or monsoonal conditions. Studies based on the coexistence approach have had a marked impact in literature, generating over 10,000 citations thus far. However, recent studies have pointed out inherent theoretical and practical problems entangled in the application of this widely used method. But so far little is known how results generated by the coexistence approach are affected by subjective errors, data errors, and violations of the basic assumptions. The majority of Coexistence Approach studies make use of the Palaeoflora database (the combination of which will be abbreviated to CA+PF). Testing results produced by CA+PF studies has been hindered by the general unavailability of the contents in the underlying Palaeoflora database; two exceptions are the mean-annual temperature tolerances and lists of assigned associations between fossils and nearest-living relatives. Using a recently published study on the Eocene of China, which provides the first usable insight into the data structure of the Palaeoflora database, we compare the theory and practice of Coexistence Approach using the Palaeoflora database (CA+PF). We show that CA+PF is riddled by association and climate data error. We reveal the flaws in the application of CA, which is often in stark contrast to the theory of the method. We show that CA+PF is highly vulnerable against numerous sources of errors, mainly because it lacks safeguards that could identify unreliable data. We demonstrate that the CA+PF produces coherent, pseudo-precise results even for artificially generated, random plant assemblages. Alternative MCR-NLR methods can surpass the most imminent deficits of CA, and may be used as a stop-gap until more accurate bioclimatic and distribution data on potential Eurasian NLRs, and theoretically- and statistically-robust methods will become available. Finally, general guidelines are provided for the future application of methods using the mutual climatic range with nearest living relatives approach when reconstructing climate from plant fossil assemblages.

Paleontology↗

bioRxiv2015

How many dinosaur species were there? Fossil bias and true richness estimated using a Poisson sampling model (TRiPS)

The fossil record is a rich source of information about biological diversity in the past. However, the fossil record is not only incomplete but has inherent biases due to geological, physical, chemical and biological factors. Our knowledge of past life is also biased because of differences in academic and amateur interests and sampling efforts. As a result, not all individuals or species that lived in the past are equally likely to be discovered at any point in time or space. To reconstruct temporal dynamics of diversity using the fossil record, biased sampling must be explicitly taken into account. Here, we introduce an approach that utilizes the variation in the number of times each species is observed in the fossil record to estimate both sampling bias and true richness. We term our technique TRiPS (True Richness estimated using a Poisson Sampling model) and explore its robustness to violation of its assumptions via simulations. We then venture to estimate sampling bias and absolute species richness of dinosaurs in the geological stages of the Mesozoic. Using TRiPS, we estimate that 1936 (1543-2468) species of dinosaurs roamed the Earth during the Mesozoic. We also present improved estimates of species richness trajectories of the three major dinosaur clades; the sauropodomorphs, ornithischians and theropods, casting doubt on the Jurassic-Cretaceous extinction event and demonstrating that all dinosaur groups are subject to considerable sampling bias throughout the Mesozoic.

Paleontology↗

bioRxiv2016

Common species link global ecosystems to climate change

Common species shape the world around us, and changes in their commonness signify large-scale shifts in ecosystem structure and function1-4. Dominant taxa drive productivity and biogeochemical cycling, in direct interaction with abiotic components of the Earth system3,4. However, our understanding of the dynamic response of ecosystems to global environmental changes in the past is limited by our ability to robustly estimate fossil taxonomic richness5,6, and by our neglect of the importance of common species. To rectify this, we use observations of the most common and widespread species to track global changes in their distribution in the deep geological past. Our simple approach is robust to factors that bias richness estimators, including widely used sampling-standardization methods5, which we show are highly sensitive to variability in the species-abundance distribution. Causal analyses of common species frequency in the deep-sea sedimentary record detect a lagged response in the ecological prominence of planktonic foraminifera to oceanographic changes captured by deep-ocean temperature records over the last 65 million years, encompassing one of Earth's major climate transitions. Our results demonstrate that common species can act as tracers of a past global ecosystem and its response to physical changes in Earth's dynamic history.

Paleontology↗

bioRxiv2016

Fossil calibrations for the arthropod Tree of Life

Fossil age data and molecular sequences are increasingly combined to establish a timescale for the Tree of Life. Arthropods, as the most species-rich and morphologically disparate animal phylum, have received substantial attention, particularly with regard to questions such as the timing of habitat shifts (e.g. terrestrialisation), genome evolution (e.g. gene family duplication and functional evolution), origins of novel characters and behaviours (e.g. wings and flight, venom, silk), biogeography, rate of diversification (e.g. Cambrian explosion, insect coevolution with angiosperms, evolution of crab body plans), and the evolution of arthropod microbiomes. We present herein a series of rigorously vetted calibration fossils for arthropod evolutionary history, taking into account recently published guidelines for best practice in fossil calibration. These are restricted to Palaeozoic and Mesozoic fossils, no deeper than ordinal taxonomic level, nonetheless resulting in 80 fossil calibrations for 102 clades. This work is especially timely owing to the rapid growth of molecular sequence data and the fact that many included fossils have been described within the last five years. This contribution provides a resource for systematists and other biologists interested in deep-time questions in arthropod evolution.\n\nABBREVIATIONS

Paleontology↗

bioRxiv2016

MUSCLES OF FACIAL EXPRESSION IN EXTINCT SPECIES OF THE GENUS HOMO

We display a detailed description of mimetic muscles in extinct human species, framed in comparative and phylogenetic contexts. Using known facial landmarks, we assessed the arrangement of muscles of facial expression in Homo sapiens, neanderthalensis, erectus, heidelbergensis and ergaster. In modern humans, several perioral muscles are proportionally smaller in size (levator labii superioris, zygomaticus minor, zygomaticus major and triangularis) and/or located more medially (levator labii superioris, zygomaticus minor and quadratus labii inferioris) than in other human species. As mimetic musculature is examined in the most ancient specimens up to the most recent, there is a general trend towards an increase in size of corrugator supercillii and triangularis. Homo ergasters mimetic musculature closely resembles modern Homo, both in size and in location; furthermore, Homo erectus and Homo neanderthalensis share many muscular features. The extinct human species had an elaborate and highly graded facial communication system, but it remained qualitatively different from that reported in modern Homo. Compared with other human species, Homo sapiens clearly exhibits a lower degree of facial expression, possibly correlated with more sophisticated social behaviours and with enhanced speech capabilities. The presence of anatomical variation among species of the genus Homo raises important questions about the possible taxonomic value of mimetic muscles.

Paleontology↗

bioRxiv2016

The case for species selection

The mere existence of speciation and extinction make macro-evolutionary processes possible. Speciation and extinction introduce discontinuities in the microevolutionary change within lineages by initiating, disrupting, and terminating the continuity of species lineages. Within a clade, speciation and extinction become potent means of macroevolution in and of themselves. This process, termed species selection, is a macroevolutionary analogue of natural selection, with species playing an analogous part akin to that played by organisms in microevolution. That said, it has proven difficult to think about levels of selection. The concept of species sorting was introduced to help our thinking on this issue by identifying two aspects inherent in hierarchical systems can confuse our attempts to understand them: uncertainty in the level that selection acts and uncertainty about if the pattern of selection is in fact caused at all. Thanks to insights from evolutionary transitions in individuality, we now know more about how to identify the level of selection and how to parse the causal structure in hierarchical evolutionary circumstances. We know that if the fitness of organisms causes the fitness of more inclusive species then they must covary. However, there is no evidence of such a covariance between fitnesses at these two levels. This covariance is just not observed; neither between cells and organisms nor between organisms and species. Rather, speciation and extinction rates appear to be completely divorced from organismal fitness. With this insight, the concept of species sorting shrinks so that it only covers the two processes of species selection and drift. I argue that we are better off focusing on understanding the processes of species selection and drift and that there is therefore no further need for the concept of species sorting.

paleontology↗

bioRxiv2017

A SUPERNOVA AT 50 PC: EFFECTS ON THE EARTHS ATMOSPHERE AND BIOTA

Recent 60Fe results have suggested that the estimated distances of supernovae in the last few million years should be reduced from [~]100 pc to [~]50 pc. Two events or series of events are suggested, one about 2.7 million years to 1.7 million years ago, and another may at 6.5 to 8.7 million years ago. We ask what effects such supernovae are expected to have on the terrestrial atmosphere and biota. Assuming that the Local Bubble was formed before the event being considered, and that the supernova and the Earth were both inside a weak, disordered magnetic field at that time, TeV-PeV cosmic rays at Earth will increase by a factor of a few hundred. Tropospheric ionization will increase proportionately, and the overall muon radiation load on terrestrial organisms will increase by a factor of [~]150. All return to pre-burst levels within 10kyr. In the case of an ordered magnetic field, effects depend strongly on the field orientation. The upper bound in this case is with a largely coherent field aligned along the line of sight to the supernova, in which case TeV-PeV cosmic ray flux increases are [~]104; in the case of a transverse field they are below current levels. We suggest a substantial increase in the extended effects of supernovae on Earth and in the \"lethal distance\" estimate; more work is needed. This paper is an explicit followup to Thomas et al. (2016). We also here provide more detail on the computational procedures used in both works.

paleontology↗

bioRxiv2017

Coral reefs in crisis: The reliability of deep-time food web reconstructions as analogs for the present

Ongoing anthropogenic alterations of the biosphere have shifted emphasis in conservation biology from individual species to entire ecosystems. Modern measures of ecosystem change, however, lack the extended temporal scales necessary to forecast future change under increasingly stressful environmental conditions. Accordingly, the assessment and reconstruction of ecosystem dynamics during previous intervals of environmental stress and climate change in deep time has garnered increasing attention. The nature of the fossil record, though, raises questions about the difficulty of reconstructing paleocommunity and paleoecosystem-level dynamics. In this study, we assess the reliability of such reconstructions by simulating the fossilization of a highly threatened and disturbed modern ecosystem, a Caribbean coral reef. Using a high-resolution coral reef food web from Jamaica, we compare system structures of the modern and simulated fossil reefs, including guild richness and evenness, trophic level distribution, predator dietary breadth, food chain lengths, and modularity. Results indicate that despite the loss of species, guilds, and trophospecies interactions, particularly zooplankton and other soft-bodied organisms, the overall guild diversity, structure, and modularity of the reef ecosystem remained intact. These results have important implications for the integrity of fossil food web studies and coral reef conservation, demonstrating that fossil reef communities can be used to understand reef community dynamics during past regimes of environmental change.

paleontology↗

bioRxiv2017

A Posteriori Evaluation Of Molecular Divergence Dates Using Empirical Estimates Of Time-Heterogeneous Fossilization Rates

The application of molecular clock concepts in phylogenetics permits estimating the divergence times of clades with an incomplete fossil record. However, the reliability of this approach is disputed, because the resulting estimates are often inconsistent with different sets of fossils and other parameters (clock models and prior settings) in the analyses. Here, we present the {lambda} statistic, a likelihood approach for a posteriori evaluating the reliability of estimated divergence times. The {lambda} statistic is based on empirically derived fossilization rates and evaluates the fit of estimated divergence times to the fossil record. We tested the performance of this measure with simulated data sets. Furthermore, we applied it to the estimated divergence times of (i) Clavigeritae beetles of the family Staphylinidae and (ii) all extant insect orders. The reanalyzed beetle data supports the originally published results, but shows that several fossil calibrations used do not increase the reliability of the divergence time estimates. Analyses of estimated inter-ordinal insect divergences indicate that uniform priors with soft bounds marginally outperform log-normal priors on node ages. Furthermore, a posteriori evaluation of the original published analysis indicates that several inter-ordinal divergence estimates might be too young. The {lambda} statistic allows the comparative evaluation of any clade divergence estimate derived from different calibration approaches. Consequently, the application of different algorithms, software tools, and calibration schemes can be empirically assessed.

paleontology↗