Paleobiology was founded 50 years ago to provide an outlet for biological paleontology, with an emphasis on investigating evolutionary patterns and processes that could apply generally across the history of life. While the intellectual and financial prospects for Paleobiology were uncertain in the beginning (Sepkoski 2012; Valentine 2009), this 50^th anniversary issue testifies to its overwhelming success. Fifty years of anything well done deserves a celebration. These moments are a time for reflection and a time for imagining future directions. With this introduction, we outline briefly the start of the journal and two landmark anniversary issues, the 10^th and the 25^th. No special issue can adequately survey all research themes in a field as intellectually rich as paleobiology. However, these anniversary issues offer a snapshot of research directions, and they can trace the shift and expansion of established fields and mark the emergence of new ones. We end by outlining the contributions to the 50^th anniversary issue that summarize current themes and future directions for the field.

The spatial distribution of individuals within ecological assemblages and their associated traits and behaviors are key determinants of ecosystem structure and function. Consequently, determining the spatial distribution of species, and how distributions influence patterns of species richness across ecosystems today and in the past, helps us understand what factors act as fundamental controls on biodiversity. Here, we explore how ecological niche modeling has contributed to understanding the spatiotemporal distribution of past biodiversity and past ecological and evolutionary processes. We first perform a semiquantitative literature review to capture studies that applied ecological niche models (ENMs) to the past, identifying 668 studies. We coded each study according to focal taxonomic group, whether and how the study used fossil evidence, whether it relied on evidence or methods in addition to ENMs, spatial scale of the study, and temporal intervals included in the ENMs. We used trends in publication patterns across categories to anchor discussion of recent technical advances in niche modeling, focusing on paleobiogeographic ENM applications. We then explored contributions of ENMs to paleobiogeography, with a particular focus on examining patterns and associated drivers of range dynamics; phylogeography and within-lineage dynamics; macroevolutionary patterns and processes, including niche change, speciation, and extinction; drivers of community assembly; and conservation paleobiogeography. Overall, ENMs are powerful tools for elucidating paleobiogeographic patterns. ENMs are most commonly used to understand Quaternary dynamics, but an increasing number of studies use ENMs to gain important insight into both ecological and evolutionary processes in pre-Quaternary times. Deeper integration with traits and phylogenies may further extend those insights.

The spatial distribution of species across the landscape and their associated traits and behaviors play a pivotal role in determining ecosystem structure and function and contribute to our understanding of the processes that shape biodiversity. Ecological niche models (ENMs) are tools that can be used to estimate the ecological niche of a species based on its known occurrences. In this review, we explore the ways that ENMs have been used to study the evolution and ecology of past biodiversity. While ENMs are commonly used to understand the dynamics of species and assemblages during more recent periods of Earth history (i.e., the last several million years), an increasing number of studies have extended ENMs deeper into the geologic past. Overall, ENMs are powerful tools for illuminating paleobiogeographic patterns; further integration of ENMs with traits, phylogenies, and other methods may extend insights.

Over the last 50 years, paleobiology has made great strides in illuminating organisms and ecosystems in deep time through study of the often-curious nature of the fossil record itself. Among fossil deposits, none are as enigmatic or as important to our understanding of the history of life as Konservat-Lagerstätten, deposits that preserve soft-bodied fossils and thereby retain disproportionately large amounts of paleobiological information. While Konservat-Lagerstätten are often viewed as curiosities of the fossil record, decades of study have led to a better understanding of the environments and circumstances of exceptional fossilization.Whereas most types of exceptional preservation require very specific sets of conditions, which are rare but can occur at any time, Seilacher noted the problem of “anactualistic” modes of exceptional preservation, defined as modes of fossilization that are restricted in time and that no longer occur. Here, we focus on anactualistic preservation and the widely recognized overrepresentation of Konservat-Lagerstätten in the Ediacaran and early Paleozoic. While exceptional fossil deposits of Ediacaran, Cambrian, and Early Ordovician age encompass a number of modes of fossilization, the signal of exceptional preservation is driven by only two modes, Ediacara-type and Burgess Shale–type preservation. Both are “extinct” modes of fossilization that are no longer present in marine environments. We consider the controls that promoted widespread anactualistic preservation in the Ediacaran and early Paleozoic and their implications for the environmental conditions in which complex life first proliferated in the oceans.

Over the last 50 years, paleobiology has made great strides in illuminating organisms and ecosystems in deep time. Sometimes, these advances have come by interrogating the actual nature of the fossil record itself, specifically, the factors that govern how and why fossils are preserved. Among fossil deposits, none are as enigmatic or as important to our understanding of the history of life as deposits that preserve soft-bodied fossils and thereby retain unusually large amounts of paleobiological information. The great German paleontologist Adolf Seilacher called such deposits “Lagerstätten,” a term now taken to signify paleontological “mother lodes.” These fossil deposits typically represent precise sets of conditions that occur extraordinarily rarely but throughout the geologic record. Some types of these extraordinary deposits, however, represent essentially extinct modes of fossilization, which no longer occur within marine environments. Here, we consider these “anactualistic” styles of fossilization that once were widespread in Earth's oceans, but only for a geologically brief period of time. We conclude that the circumstances that caused these lost pathways of fossil preservation resulted from specific suites of conditions that dominated ancient oceans during the rise of animal life. The same conditions that promoted anactualistic fossilization may have important implications for the circumstances in which complex life first proliferated in the oceans.

Stratigraphic paleobiology uses a modern understanding of the construction of the stratigraphic record—from beds to depositional sequences to sedimentary basins—to interpret patterns and guide sampling strategies in the fossil record. Over the past 25 years, its principles have been established primarily through forward numerical modeling, originally in shallow-marine systems and more recently in nonmarine systems.

Stratigraphic paleobiology uses a modern understanding of the construction of the stratigraphic record—from beds to depositional sequences to sedimentary basins—to interpret patterns and guide sampling strategies in the fossil record. Over the past 25 years, its principles have been established primarily through forward numerical modeling, originally in shallow-marine systems and more recently in nonmarine systems. Predictions of these models have been tested through outcrop-scale and basin-scale field studies, which have also revealed new insights. At multi-basin and global scales, understanding the joint development of the biotic and sedimentary records has come largely from macrostratigraphy, the analysis of gap-bound packages of sedimentary rock. Here, we present recent advances in six major areas of stratigraphic paleobiology, including critical tests in the Po Plain of Italy, mass extinctions and recoveries, contrasts of shallow-marine and nonmarine systems, the interrelationships of habitats and stratigraphic architecture, large-scale stratigraphic architecture, and the assembly of regional ecosystems. We highlight the potential for future research that applies stratigraphic paleobiological concepts to studies of climate change, geochemistry, phylogenetics, and the large-scale structure of the fossil record. We conclude with the need for more stratigraphic thinking in paleobiology.

Evolutionary success comes to the selfish—or so most of us are taught. Those organisms that reproduce most will of course be better represented in future generations. Current theory has had great success in understanding much of evolution, but it hits a wall when it comes to understanding how ancestrally solitary organisms can aggregate to form new wholes. Current theory expects that the evolution of new wholes is undermined by the selfishness of the parts; if the parts keep reproducing, an emergent whole cannot originate. Yet every animal is a living contradiction of current theory. During development, animal cells divide in the same way their solitary ancestors reproduced, while concurrently the whole animal reproduces itself.

The fitness of groups is often considered to be the average fitness among constituent members. This assumption has been useful for developing models of multilevel selection, but its uncritical adoption has held back our understanding of how multilevel selection actually works in nature. If group fitness is only equal to mean member fitness, then it is a simple task to erode the importance of group-level selection in all multilevel scenarios—species selection could then be reduced to organismal selection as easily as group selection can. Because selection from different levels can act on a single trait, body size, for example, there must be a way to translate one level of fitness to another. This allows the calculation of the contributions of selection at each level. If high-level fitness is not a simple function of member fitness, then how do they interlace? Here we reintroduce Leigh Van Valen's argument for the inclusion of expansion as a component of fitness. We show that expansion is an integral part of fitness even if one does not subscribe to the energetic view of fitness from which Van Valen originally derived it. From a hierarchical perspective, expansion is the projection of demographic fitness from one level to the next level up; differential births and deaths at one level produce differential expansion one level above. Including expansion in our conceptual tool kit helps allay concerns about our ability to identify the level of selection using a number of methods as well as allowing for the various forms of multilevel selection to be seen as manifestations of the same basic process.

Every organism interacts with a host of other organisms of the same and different species throughout its life. These biotic interactions have varying influences on the reproduction and dispersal of the organism, and hence also the population and species lineage to which the organism belongs. By extension, biotic interactions must contribute to the macroevolutionary patterns that we observe in the fossil record, but exactly how, when, and why are research questions we have been asking before the start of the journal Paleobiology. In this contribution for Paleobiology's 50^th anniversary, we present a brief overview of how paleobiologists have studied biotic interactions and their macroevolutionary consequences, recognizing paleontology's unique position to contribute data and insights to the topic of interspecies interactions. We then explore, in a semi-free-form manner, what promising avenues might be open to those of us who use the fossil record to understand biotic interactions. In general, we emphasize the need for increased effort surrounding the understanding of ecological details, integration of different types of information, and model-based approaches.

Every animal and plant interacts with many other individuals, including disease-causing organisms, prey items, or pollinators, throughout their lives. These interactions necessarily contribute to the ecological and evolutionary processes that are associated with the diverse forms of life that we observe. It is comparatively easy to study such biotic interactions among living organisms, but more challenging to investigate such relationships when the organisms involved are dead or their species extinct. We discuss how paleobiologists have studied biotic interactions in the last 50 years, then suggest new avenues of research we could continue to fruitfully explore.

Extreme environmental changes have pushed global biodiversity past its breaking point just a handful of times, now referred to as the “Big Five” mass extinctions. These events probably represent “perfect storms,” where individual pressures, often severe in themselves, combine to catastrophic effect, driving sweeping changes to the biota. Better constraints on the timing of biotic and environmental changes and on the spatial locations and biologies of victims and survivors have improved analyses aiming to identify the roles of traits and other factors in promoting survival. These new data also help to identify hitchhiking effects, where certain evolutionary lineages or biological traits were lost or survived not because of the direct action of the extinction drivers, but because they were carried along by other traits, such as geographic-range size. Adding other dimensions or currencies of biodiversity, such as biological form or function, gives further insights into the evolutionary roles of mass extinctions: modes of life are surprisingly extinction-resistant, even in the face of extensive species loss. However, the extinction filter is just one major factor in reshaping biodiversity at these events. Longer-term impacts also flow partly from their ensuing rebounds, and more work is needed to uncover the circumstances that spur some groups and modes of life to re-diversify while others are relegated to marginal roles in the post-extinction world. Analyses of past extinction events and their rebounds bring macroevolutionary insights to the present-day biodiversity crisis—approaching a “perfect storm” in the intensity and scale of its pressures—and help to pinpoint the lineages, modes of life, and organismal forms most vulnerable to extinction and failed rebounds.

Mass extinctions are natural experiments on the short- and long-term consequences of pushing biotas past breaking points, often with lasting effects on the structure and function of biodiversity. General properties of mass extinctions—exceptionally severe, taxonomically broad, global losses of taxa—are starting to come into focus through comparisons among dimensions of biodiversity, including morphological, functional, and phylogenetic diversity. Notably, functional diversity tends to persist despite severe losses of taxonomic diversity, whereas taxic and morphological losses may or may not be coupled. One of the biggest challenges in synthesizing and extracting general consequences of these events has been that they are often driven by multiple, interacting pressures, and the taxa and their traits vary among events, making it difficult to link single stressors to specific traits. Ongoing improvements in the taxonomic and stratigraphic resolution of these events for multiple clades will sharpen tests for selectivity and help to isolate hitchhiking effects, whereby organismal traits are carried by differential survival or extinction of taxa owing to other organismal or higher-level attributes, such as geographic-range size. Direct comparative analyses across multiple extinction events will also clarify the impacts of particular drivers on taxa, functional traits, and morphologies. It is not just the extinction filter that deserves attention, as the longer-term impact of extinctions derives in part from their ensuing rebounds. More work is needed to uncover the biotic and abiotic circumstances that spur some clades into re-diversification while relegating others to marginal shares of biodiversity. Combined insights from mass extinction filters and their rebounds bring a macroevolutionary view to approaching the biodiversity crisis in the Anthropocene, helping to pinpoint the clades, functional groups, and morphologies most vulnerable to extinction and failed rebounds.

Paleobiology can offer diverse insights into how climate change has affected past species and ecosystems. Timely and important areas of research focus on the potential of paleobiology to contribute to solutions for climate impacts on natural ecosystems. But how far can past responses to abrupt climate change be generalized to derive predictions for the modern and future worlds? The long timescales over which biological responses are observed in the deep-time past hamper the applicability of paleontological observations, but by how much? To address these questions, we review paleontological evidence for the impacts of geologically rapid climatic change. Fruitful avenues for future research lie in (1) characterizing the relationship between the magnitude of warming and extinction toll, (2) using physiology to bridge timescales, and (3) assessing the role of long-term climate history to predict the impact of short-term climate change. Identifying how consistent and robust paleontological signals are across timescales will help to make deep-time observations more useful for the modern world.

Ancient changes in the biosphere, from organismic traits to wholesale ecosystem changes, can be aligned with climate forcing across the Phanerozoic. Clear examples of abrupt climate warming causing biodiversity crises are primarily found between the Permian and Paleogene periods. During these times, catastrophic events occurred, resembling the extreme climate scenarios projected for the near future. The paleobiologic literature around these events generally supports the hypothesis that abrupt climate change was a dominant trigger of extinction and/or ecological crisis. When climate change and climate history are considered, virtually all post-Paleozoic global biotic events can be confidently attributed to climatic change, with abrupt warming (hyperthermal events) leaving the most consistent fingerprint. The combined stress of deoxygenation and warming are sufficient to explain marine extinction patterns across most hyperthermal events. Although ocean acidification may have contributed, the direct role of pH on the extinction toll of organisms is not consistently demonstrated. Future research can enhance the correspondence between the magnitudes of climatic changes and their biological impacts, even though observed rates of change cannot currently be compared across different timescales. Mimicking multi-scale approaches in modern ecology, paleontological approaches to climate impact research will benefit from specifically targeting scaling relationships.

We present an overview of conservation paleobiology and the directions in which the field could progress in the next 50 years to aid conservation. To do so, we use elasmobranchs (sharks, rays, and skates), one of the mostly highly marine endangered groups today, as a model. The perspectives we share are guided by current conservation priorities and recent advances in elasmobranch paleobiology and are developed around four main topics. For each topic, we outline knowledge gaps, discuss the potential of near- and deep-time records to contribute relevant information, highlight examples, and suggest research directions. Ultimately, we aim at focusing conservation paleobiology research agendas, encouraging collaborations across timescales, and distilling lessons that could be transferred to other threatened but understudied taxa in conservation paleobiology.

Humans have dramatically transformed ecosystems over the previous millennia and are potentially causing a mass extinction event comparable to the others that shaped the history of life. However, only a fraction of these impacts has been directly recorded, limiting conservation actions. Conservation paleobiology leverages geohistorical records to offer a long-term perspective on biodiversity change in the face of anthropogenic stressors. Nevertheless, the field's on-the-ground contributions to conservation outcomes are still developing. Here, we present an overview of directions in which paleobiological research could progress to aid conservation in the coming decades using elasmobranchs (sharks, rays, and skates)—a highly threatened group with a rich fossil record—as a model. These research directions are guided by areas of overlap between an expert-led list of current elasmobranch conservation priorities and available fossil and historical records. Four research topics emerged for which paleobiological research could address open questions in elasmobranch science and conservation: (1) baselines, (2) ecological roles, (3) threats, and (4) conservation priorities. Increasingly rich datasets and novel analytical frameworks present exciting opportunities to apply the elasmobranch fossil record to conservation practice. A similar approach could be extended to other clades. Given the synthetic nature of these research topics, we encourage collaboration across timescales and with conservation practitioners to safeguard the future of our planet's rapidly disappearing species.

The first compilations of Proterozoic eukaryote diversity, published in the 1980s showed a dramatic peak in the Tonian Period (1000–720 Ma), interpreted as the initial radiation of eukaryotes in the marine realm. Over the decades, new discoveries filled in the older part of the record and the peak diminished, but the idea of a Tonian radiation of eukaryotes has remained strong, and is now widely accepted as fact. We present a new diversity compilation based on 181 species and 713 species occurrences from 145 formations ranging in age from 1890 Ma to 720 Ma and find a significant increase in diversity in the Tonian. However, we also find that the number of eukaryotic species through time is highly correlated with the number of formations in our dataset (i.e. eukaryote-bearing formations) through time. This correlation is robust to interpretations of eukaryote affinity, bin size, and bin boundaries. We also find that within-assemblage diversity—a measure thought to circumvent sampling bias—is related to the number of eukaryote-bearing formations through time. Biomarkers show a similar pattern to body fossils, where the rise of eukaryotic biosignatures correlates with increased sampling. We find no evidence that the proportion of eukaryote-bearing versus all fossiliferous formations changed through the Proterozoic, as might be expected if the correlation reflected an increase in eukaryote diversity driving an increase in the number of eukaryote-bearing formations. Although the correlation could reflect a common cause such as changes in sea level driving both diversification and an increase in sedimentary rock volume, we favor the explanation that the pattern of early eukaryote diversity is driven by variations in paleontological sampling.

The discipline of Precambrian paleontology—the study of early life— is not much older than the journal Paleobiology. We focus on the early fossil record of eukaryotes, a group that early in its history was represented by single-celled organisms (i.e., protists), and review how our understanding of early eukaryote diversification has changed in the last half century. In addition, we present our own analysis of diversity patterns over the >1 billion year time interval preceding the snowball Earth glaciations circa 720 million years ago. Analyses from the 1980s found evidence for a dramatic peak in diversity in the mid- to late Tonian Period, inspiring the hypothesis that eukaryotes rose to dominance during this time. With additional discoveries, the contrast between Tonian diversity and that of earlier time intervals has diminished, calling into question the “Tonian radiation” hypothesis. Our new analysis shows that the number of eukaryotic species through time is strongly correlated with the number of eukaryote-bearing formations through time, suggesting that sampling may be the dominant driver of early eukaryote diversity patterns. We also find no evidence that the proportion of eukaryote-bearing versus all fossiliferous formations (including only prokaryote-bearing formations) changed through this time, as might be expected if the radiation of eukaryotes drove an increase in the number of eukaryote-bearing formations. (The one exception is the late Tonian chert window, when vase-shaped microfossils appeared in these otherwise eukaryote-poor, restricted, organic-rich, and often hypersaline environments.) Biomarkers show a similar pattern to body fossils, wherein the rise of eukaryotic biosignatures correlates with increased sampling. These results raise the prospect that the Tonian radiation is an artifact of sampling and suggest that 50 years on, we still do not know the broad pattern of early eukaryote diversity.

Animals first evolved more than 570 million years ago, during the Ediacaran time period, but it was not until well into the Cambrian time period, around 520 million years ago, that animal evolution really took off and most modern animal groups diversified. It is over this Ediacaran to Cambrian transition that we not only see animals first appear, but also the evolution of movement, the ability to burrow and to swim, and the very first reefs and macroscopic predators. There are likely many different factors that shaped this radiation of animal life, so in this review paper we discuss the ecology underlying this Ediacaran to Cambrian transition and place the individual specimens and taxa in the context of the environment in which they lived. After all, it is the interactions that organisms experienced in their daily lives with one another and their environment that led to the diversification of animal body plans, and the evolutionary patterns we observe over these crucial 75 million years. As early animals evolved, we see diversification in feeding and biological and environmental interactions. These ecological interactions started off relatively weak, with few interactions between organisms, but then increased throughout the Ediacaran and into the Cambrian. By 500 million years ago, the ecosystem structure was similar to that of marine systems today. However, there are time delays between the origins of structuring processes and the time when they have an observed impact on other organisms and their ecosystem. As such, while the key building blocks of ecosystem structure were in place by the end of the Cambrian, it takes evolutionary timescales for the impact of these innovationsto be realized.

The Ediacaran/Cambrian transition (ECT; ∼575–500 Ma) captures the early diversification of animals, including the oldest crown-group taxa of most major animal phyla alive today. Key to understanding the drivers underneath the ECT macroevolutionary patterns are the interactions of animals with one another and their environment, and how these interactions scale up to global diversity patterns. Understanding the ecology of ECT organisms is enabled by the abundance of Lagerstätten over this time period, with a relatively large proportion of soft-bodied organisms preserved, often within the communities in which they lived. Here, we review our understanding of organismal, community, and macroecology of the ECT, and how these different scales of ecological analyses relate to the macroevolutionary diversification patterns we see over this 75 Myr time period. Across all ecological scales, we find clear trends, starting with stochastic ecosystem dynamics dominated by generalist taxa in the first Ediacaran communities, to more structured, niche-driven specialist dynamics by Cambrian Epoch 2. These trends are reflected in organism functional morphology, the complexity and strength of organisms' interactions within their communities, and large-scale metacommunity, biogeographic, and biodiversity patterns. Yet there is often a time delay between the origination of a new type of ecological interaction and when it is observed to impact the ecosystem as a whole. As such, while many modern ecological innovations were in place by the end of the Cambrian, the knock-on effects and complexity of these interactions continued to build up throughout the Phanerozoic, leading to the complex biosphere we have today.

The Paleozoic evolution of a complex terrestrial biota has been among the most important events in Earth history. Here, we synthesize paleontological and neontological information across the different threads of the biota—including microbial life, fungi, animals, and plants—addressing discrepancies between the fossil record and time-calibrated molecular phylogenies. Four fundamental patterns are emphasized: (1) Most terrestrial animal lineages consist of diminutive inhabitants of soil and litter, with the soil fauna exhibiting remarkable continuity between the Paleozoic and present. (2) Faunal evolution tracks the ecological opportunities afforded by the evolution of the land flora. Flora and fauna alike were initially confined to the thin interface between soil and air, but animals explored both flight and burrowing as vascular plant size increased to encompass tree stature and deep rooting. (3) Skewed nutrient ratios of land plants present a fundamental challenge for animals that are accommodated through contrasting size-based dietary strategies. Detritivory and cell-by-cell herbivory are the diets most readily available for primary consumers but impose limits on the largest possible body sizes; only with subsequent evolution of herbivory in insects and then vertebrates could the dramatic increases in size in the Permian and Mesozoic have been achieved. (4) A second pulse of animal terrestrializations is apparent in the Cretaceous and Cenozoic that might be attributed to increased terrestrial productivity associated with angiosperm evolution. However, environmental changes to nutrient availability earlier in the Mesozoic prevent an unambiguous causal attribution, and the pulse may just be an artifact of our modern vantage point.

The Paleozoic evolution of a complex terrestrial biota has been among the most important events in Earth history. Here, we address how to integrate information from fossil and extant life highlighting four fundamental patterns: (1) The soil fauna shows remarkable continuity over 400 million years through to the present. (2) The evolution of animal ecologies closely tracks the opportunities provided by plant evolution via flight and burrowing as plants evolved the canopy stature and rooting depth of trees. (3) The skewed nutrient ratios of plants are a challenge that can be avoided by means of small body size, but that then places limits on the maximum body sizes seen before the evolution of insect and vertebrate herbivores. (4) The most recent 150 million years suggest a second pulse of animal terrestrializations, perhaps related to the evolution of flowering plants, but this linkage is questionable.

Organismal morphology was at the core of study of biodiversity for millennia before the formalization of the concept of evolution. In the early to mid-twentieth century, a strong theoretical framework was developed for understanding both pattern and process of morphological evolution, and the 50 years since the founding of this journal capture a transformational period in the quantification of morphology and in analytical tools for estimating how morphological diversity changes through time. We are now at another inflection point in the study of morphological evolution, with the availability of vast amounts of high-resolution data sampling extant and extinct diversity allowing “omics”-scale analysis. Artificial intelligence is accelerating the pace of phenomic data acquisition even further. This new reality, in which the ability to obtain data is quickly outpacing the ability to analyze it with robust, realistic evolutionary models, brings a new set of challenges. Phylogenetic comparative methods have provided new insights into the processes generating morphological diversity, but the reliance on molecular data and resultant exclusion of fossil data from most large phylogenetic trees has well-established negative impacts on evolutionary analyses, as we demonstrate with examples of standard single-rate evolutionary models, mode- and rate-shift models, and a recently described Ornstein-Uhlenbeck climate model. Further development of methods for phylogenetic comparative analysis of high-dimensional data is needed, but existing tools can refine our understanding and expectations of morphological evolution and the generation of morphological diversity under different scenarios, as we demonstrate with analyses of placental skull evolution through the Cenozoic. Fully transitioning the study of morphological evolution into the omics era will involve the development of tools to automate the extraction of meaningful, comparable morphometric data from images, integrate fossil data into large phylogenetic trees and downstream evolutionary analyses, and generate robust models that accurately reflect the complexity of evolutionary processes and are well-suited for high-dimensional data. Combined, these advancements will solidify the emerging field of evolutionary phenomics and appropriately center it around the analysis of deep-time data.

Organismal morphology was at the core of study of biodiversity for millennia before the formalization of the concept of evolution. In the early to mid-twentieth century, a strong theoretical framework was developed for understanding both pattern and process of morphological evolution. The 50 years since the founding of this journal capture a transformational period for the study of evolutionary morphology, in both how it is measured and how changes through time are reconstructed. We are now at another key transition point in the study of morphological evolution, with the availability of vast amounts of high-resolution data sampling living and extinct species allowing “omics”-scale analysis. Artificial intelligence is accelerating the pace of phenomic (high-dimensional, organism-wide) data collection. This new reality, in which the ability to obtain data is quickly outpacing the ability to analyze it with robust, realistic evolutionary models, brings a new set of challenges. Fully transitioning the study of morphological evolution into the omics era will involve the development of tools to automate the extraction of meaningful, comparable morphometric data from images, integrate fossil data into large phylogenetic trees and downstream evolutionary analyses, and generate models that accurately reflect the complexity of evolutionary processes and are well-suited for high-dimensional data. Combined, these advancements will solidify the emerging field of evolutionary phenomics and appropriately center it around the analysis of deep-time data.

Incorporating paleontological data into phylogenetic inference can greatly enrich our understanding of evolutionary relationships by providing insights into the diversity and morphological evolution of a clade over geological timescales. Phylogenetic analysis of fossil data has been significantly aided by the introduction of the fossilized birth–death (FBD) process, a model that accounts for fossil sampling through time. A decade on from the first implementation of the FBD model, we explore its use in more than 170 empirical studies, summarizing insights gained through its application. We identify a number of challenges in applying the model in practice: it requires a working knowledge of paleontological data and their complex properties, Bayesian phylogenetics, and the mechanics of evolutionary models. To address some of these difficulties, we provide an introduction to the Bayesian phylogenetic framework, discuss important aspects of paleontological data, and finally describe the assumptions of the models used in paleobiology. We also present a number of exemplar empirical studies that have used the FBD model in different ways. Through this review, we aim to provide clarity on how paleontological data can best be used in phylogenetic inference. We hope to encourage communication between model developers and empirical researchers, with the ultimate goal of developing models that better reflect the data we have and the processes that generated them.

Reconstructing evolutionary relationships among organisms provides important insight into the history of life on Earth. Evolutionary (phylogenetic) trees can be used to show the relationships between extinct and extant organisms. By incorporating fossils, we can then estimate the timing of significant events such as a speciation event. The models used to generate trees in paleobiology combine different data sources, including molecular sequences from living organisms, the ages of fossils, and morphological information from both. Using this framework, we can learn about the rate of evolutionary dynamics of organisms, for example, the rate of speciation or diversification, or geographic movements through time. In this review article, we describe details of the statistical modeling framework used to integrate observations from living and fossil taxa. In particular, we focus on the use of the fossilized birth–death process, which is the only available model that allows us to include knowledge about the structure of the paleontological record into phylogenetic analyses. Because not all organisms and environments are equally well preserved, a flexible framework for working with fossils is essential for obtaining reliably dated phylogenies. In the decade since the model first became available in phylogenetic software, it has been used in more than 170 studies. We celebrate different applications of the model and highlight practical challenges. An important point that emerges from our discussion is that both the complexity of fossil data and details of the assumptions made by different models are crucial to consider. We hope to stimulate the exchange of ideas between researchers collecting and curating paleontological data and those developing models and software, with a view to further improving approaches to studying evolution in deep time.

In the last 50 years, the field of paleobiology has undergone a computational revolution that opened multiple new avenues for recording, storing, and analyzing vital data on the history of life on Earth. With these advances, the amount of data available for research has grown, but so too has our responsibility to ensure that our data tools and infrastructures continue to innovate in order to best serve our diverse community. This review focuses on data equity in paleobiology, an aspirational goal, wherein data in all forms are collected, stored, shared and analyzed in a responsible, equitable, and sustainable manner. While there have been many advancements across the last five decades, inequities persist. Our most significant challenges relate to several interconnected factors, including ethical data collection, sustainable infrastructure, socioeconomic biases, and global inequalities. We highlight the ways in which data equity is critical for paleobiology and stress the need for collaborative efforts across the paleobiological community to urgently address these data equity challenges. We also provide recommendations for actions from individuals, teams, academic publishers, and academic societies in order to continue enhancing data equity and ensuring an equitable and sustainable future for our field.

The study of the history of life (paleobiology) relies heavily on data preserved in various forms. Over the past 50 years, there has been a big shift toward using computers and other technology to store and analyze these data, opening up new possibilities for research. As a result, the amount of data available has increased dramatically. However, with this growth comes the responsibility to make sure everyone in the paleobiological community can collect, store, share, analyze, and use data in a fair and sustainable way. This review looks at how well we have done in this regard over the past five decades and what challenges still lie ahead. While progress has been made in creating tools for sharing digital data, there are still many issues we must address. These include the process of how fossil data are collected and biases based on social and economic factors (e.g., wealth and access to resources). To address these challenges, everyone in the paleobiological community needs to work together. We provide suggestions for actions that individuals, their teams, academic journals, and societies can take to promote equity in the field now and into the future.