Elements of Paleontology – serie
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35 produkter
35 produkter
Expanded Sampling Across Ontogeny in Deltasuchus motherali (Neosuchia, Crocodyliformes)
Revealing Ecomorphological Niche Partitioning and Appalachian Endemism in Cenomanian Crocodyliforms
Häftad, Engelska, 2021
232 kr
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New material attributable to Deltasuchus motherali, a neosuchian from the Cenomanian of Texas, provides sampling across much of the ontogeny of this species. Detailed descriptions provide information about the paleobiology of this species, particularly with regards to how growth and development affected diet. Overall snout shape became progressively wider and more robust with age, suggesting that dietary shifts from juvenile to adult were not only a matter of size change, but of functional performance as well. These newly described elements provide additional characters upon which to base more robust phylogenetic analyses. The authors provide a revised diagnosis of this species, describing the new material and discussing incidents of apparent ontogenetic variation across the sampled population. The results of the ensuing phylogenetic analyses both situate Deltasuchus within an endemic clade of Appalachian crocodyliforms, separate and diagnosable from goniopholidids and pholidosaurs, herein referred to as Paluxysuchidae. This title is also available as Open Access on Cambridge Core.
Testing Character Evolution Models in Phylogenetic Paleobiology
A case study with Cambrian echinoderms
Häftad, Engelska, 2021
232 kr
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Macroevolutionary inference has historically been treated as a two-step process, involving the inference of a tree, and then inference of a macroevolutionary model using that tree. Newer models blend the two steps. These methods make more complete use of fossils than the previous generation of Bayesian phylogenetic models. They also involve many more parameters than prior models, including parameters about which empiricists may have little intuition. In this Element, we set forth a framework for fitting complex, hierarchical models. The authors ultimately fit and use a joint tree and diversification model to estimate a dated phylogeny of the Cincta (Echinodermata), a morphologically distinct group of Cambrian echinoderms that lack the fivefold radial symmetry characteristic of extant members of the phylum. Although the phylogeny of cinctans remains poorly supported in places, this Element shows how models of character change and diversification contribute to understanding patterns of phylogenetic relatedness and testing macroevolutionary hypotheses.
Follow the Fossils
Developing Metrics for Instagram as a Natural Science Communication Tool
Häftad, Engelska, 2021
232 kr
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The ability for people to connect, learn, and communicate about science has been enhanced through the Internet, specifically through social media platforms. Facebook and Twitter are well-studied, while Instagram is understudied. This Element provides insight into using Instagram as a science education platform by pioneering a set of calculated metrics, using a paleontology-focused account as a case study. Framed by the theory of affinity spaces, the authors conducted year-long analyses of 455 posts and 139 stories that were created as part of an informal science learning project. They found that team activity updates and posts outside of their other categories perform better than their defined categories. For Instagram stories, the data show that fewer slides per story hold viewers' attention longer, and stories using the poll tool garnered the most interaction. This Element provides a baseline to assess the success of Instagram content for science communicators and natural science institutions.
232 kr
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The echinoderms are an ideal group to understand evolution from a holistic, interdisciplinary framework. The genetic regulatory networks underpinning development in echinoderms are some of the best known for any model group. Additionally, the echinoderms have an excellent fossil record, elucidating in in detail the evolutionary changes underpinning morphological evolution. In this Element, the echinoderms are discussed as a model group for molecular palaeobiological studies, integrating what is known of their development, genomes, and fossil record. Together, these insights shed light on the molecular and morphological evolution underpinning the vast biodiversity of echinoderms, and the animal kingdom more generally.
215 kr
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The extraxial-axial theory (EAT) and universal elemental homology (UEH) are often portrayed as mutually exclusive hypotheses of homology within pentaradiate Echinodermata. EAT describes homology upon the echinoderm bauplan, interpreted through early post-metamorphic growth and growth zones, dividing it into axial regions generally associated with elements of the ambulacral system and extraxial regions that are not. UEH describes the detailed construction of the axial skeleton, dividing it into homologous plates and plate series based on symmetry, early growth, and function. These hypotheses are not in conflict; the latter is rooted in refinement of the former. Some interpretive differences arise because many of the morphologies described from eleutherozoan development are difficult to reconcile with Paleozoic forms. Conversely, many elements described for Paleozoic taxa by UEH, such as the peristomial border plates, are absent in eleutherozoans. This Element recommends these two hypotheses be used together to generate a better understanding of homology across Echinodermata.
What Does Graptolite Origination and Extinction Reveal about the Cause of the Late Ordovician Mass Extinction?
Häftad, Engelska, 2026
232 kr
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Assesses the macroevolutionary turnover of paleotropical planktic graptolites during the Late Ordovician Mass Extinction (LOME) via automated sequencing and capture-mark-recapture modeling. Graptolites exhibited a succession of turnover pulses (sensu Elizabeth Vrba) that were coincident with the main phases of the Hirnantian glaciation and during which the Diplograptina experienced declining metapopulation size, elevated extinction, zero species originations, and ultimately, complete extermination. Concurrently, the Neograptina (latest Katian temperate zone immigrants) exhibit pulses of both extinction and adaptive radiation. Thus, the LOME involved intense species selection and the wholesale alteration of the clade diversity structure of a major element of the zooplankton. The LOME is unlikely to have been a direct effect of ocean anoxia or sampling bias but rather resulted from Hirnantian climate change, which altered nutrient supplies and plankton community compositions along with ecological displacement and loss of habitat that together drove the succession of turnover pulses. This title is also available as open access on Cambridge Core.
What Does Graptolite Origination and Extinction Reveal about the Cause of the Late Ordovician Mass Extinction?
Inbunden, Engelska, 2026
748 kr
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Assesses the macroevolutionary turnover of paleotropical planktic graptolites during the Late Ordovician Mass Extinction (LOME) via automated sequencing and capture-mark-recapture modeling. Graptolites exhibited a succession of turnover pulses (sensu Elizabeth Vrba) that were coincident with the main phases of the Hirnantian glaciation and during which the Diplograptina experienced declining metapopulation size, elevated extinction, zero species originations, and ultimately, complete extermination. Concurrently, the Neograptina (latest Katian temperate zone immigrants) exhibit pulses of both extinction and adaptive radiation. Thus, the LOME involved intense species selection and the wholesale alteration of the clade diversity structure of a major element of the zooplankton. The LOME is unlikely to have been a direct effect of ocean anoxia or sampling bias but rather resulted from Hirnantian climate change, which altered nutrient supplies and plankton community compositions along with ecological displacement and loss of habitat that together drove the succession of turnover pulses. This title is also available as open access on Cambridge Core.
748 kr
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The National Park System encompasses geological exposures that preserve globally significant paleobotanical resources. These paleobotanical resources represent a broad temporal, geographic, stratigraphic, and taxonomic distribution and pose a variety of management, research, and curation concerns. In this Element, the authors present a baseline inventory of the Cenozoic paleobotany of the National Park System as a first step in stimulating new research, curation, and outreach projects that utilize these resources. The authors describe the stratigraphic, taxonomic, spatial, and temporal distribution of Cenozoic paleobotanical resources in 74 National Park Units and show that these resources vary widely in their significance and management needs. Their baseline inventory elucidates what resources need intensified management protocols and celebrates the success stories of NPS paleontological resource management that make NPS lands an essential archive of North American paleobotanical history.
232 kr
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The National Park System encompasses geological exposures that preserve globally significant paleobotanical resources. These paleobotanical resources represent a broad temporal, geographic, stratigraphic, and taxonomic distribution and pose a variety of management, research, and curation concerns. In this Element, the authors present a baseline inventory of the Cenozoic paleobotany of the National Park System as a first step in stimulating new research, curation, and outreach projects that utilize these resources. The authors describe the stratigraphic, taxonomic, spatial, and temporal distribution of Cenozoic paleobotanical resources in 74 National Park Units and show that these resources vary widely in their significance and management needs. Their baseline inventory elucidates what resources need intensified management protocols and celebrates the success stories of NPS paleontological resource management that make NPS lands an essential archive of North American paleobotanical history.
748 kr
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This Element argues for the benefits of integrating the perspectives of a new historiography of paleontology in the training of upcoming paleontologists and in the paleontological community's culture more broadly. Wrestling with the complex legacy of its past, the paleontological community is facing the need to reappreciate its history to address issues of accessibility and equity affecting the field, such as gender gap, parachute science, and specimen repatriation. The ability of the paleontological community to address these issues depends partly on the nature of its engagement with the past in which they find their source. This Element provides a conceptual toolkit to help with the interpretation of the unprecedented position in which the paleontological community finds itself regarding its past. It also introduces historiographical resources and provides some suggestions to foster collaboration between paleontology and the history of paleontology.
232 kr
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This Element argues for the benefits of integrating the perspectives of a new historiography of paleontology in the training of upcoming paleontologists and in the paleontological community's culture more broadly. Wrestling with the complex legacy of its past, the paleontological community is facing the need to reappreciate its history to address issues of accessibility and equity affecting the field, such as gender gap, parachute science, and specimen repatriation. The ability of the paleontological community to address these issues depends partly on the nature of its engagement with the past in which they find their source. This Element provides a conceptual toolkit to help with the interpretation of the unprecedented position in which the paleontological community finds itself regarding its past. It also introduces historiographical resources and provides some suggestions to foster collaboration between paleontology and the history of paleontology.
232 kr
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People hold a variety of prior conceptions that impact their learning. Prior conceptions that include erroneous or incomplete understandings represent a significant barrier to durable learning, as they are often difficult to change. While researchers have documented students' prior conceptions in many areas of geoscience, little is known about prior conceptions involving paleontology. In this Element, data on student prior conceptions from two introductory undergraduate paleontology courses are presented. In addition to more general misunderstandings about the nature of science, many students hold incorrect ideas about methods of historical geology, Earth history, ancient life, and evolution. Of special note are student perceptions of the limits of paleontology as scientific inquiry. By intentionally eliciting students' prior conceptions and implementing the pedagogical strategies described in other Elements in this series, lecturers can shape instruction to challenge this negative view of paleontology and improve student learning.
232 kr
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Lecturing has been a staple of university pedagogy, but a shift is ongoing because of evidence that active engagement with content helps strengthen learning and build more advanced skills. The flipped classroom, which delivers content to students outside of the class meeting, is one approach to maximize time for active learning. The fundamental benefit of a flipped class is that students learn more, but ensuring student preparation and engagement can be challenging. Evaluation policies can provide incentives to guide student effort. Flipping a class requires an initial time commitment, but the workload associated with evaluating student work during the course can be mitigated. The personal interactions from active learning are extremely rewarding for students and instructors, especially when class sizes are small and suitable room layouts are available. Overall, flipping a course doesn't require special training, just a willingness to experiment, reflect, and adjust.
232 kr
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New online resources are opening doors for education and outreach in the Earth sciences. One of the most innovative online earth science portals is Macrostrat and its mobile client Rockd - an interface that combines geolocated geological maps with stratigraphic information, lithological data, and crowd-sourced images and descriptions of outcrops. These tools provide a unique educational opportunity for students to interact with primary geological data, create connections between local outcrops and global patterns, and make new field observations. Rockd incorporates an aspect of social media to its platform, which creates a sense of community for users. This Element outlines these resources, gives instructions on how to use them, and provides examples of how to integrate these resources into a variety of paleontology and earth science courses.
232 kr
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Research on learning and cognition in geoscience education research and other discipline-based education communities suggests that effective instruction should include three key components: a) activation of students' prior knowledge on the subject, b) an active learning pedagogy that allows students to address any existing misconceptions and then build a new understanding of the concept, and c) metacognitive reflections that require students to evaluate their own learning processes during the lesson. This Element provides an overview of the research on student-centered pedagogy in introductory geoscience and paleontology courses and gives examples of these instructional approaches. Student-centered learning shifts the power and attention in a classroom from the instructor to the students. In a student-centered classroom, students are in control of their learning experience and the instructor functions primarily as a guide. Student-centered classrooms trade traditional lecture for conceptually-oriented tasks, collaborative learning activities, new technology, inquiry-based learning, and metacognitive reflection.
Beyond Hands On
Incorporating Kinesthetic Learning in an Undergraduate Paleontology Class
Häftad, Engelska, 2018
232 kr
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Hands-on learning in paleontology, and geology in general, is fairly common practice. Students regularly use rocks, fossils, and data in the classroom throughout their undergraduate career, but they typically do it sitting in a chair in a lab. Kinesthetic learning is a teaching model that requires students to be physically active while learning. Students may be involved in a physical activity during class or might be using their own bodies to model some important concept. This Element briefly discusses the theory behind kinesthetic learning and how it fits into a student-centered, active-learning classroom. It then describes in detail methods for incorporating it into student exercises on biostratigraphy, assessment of sampling completeness, and modeling evolutionary processes. Assessment data demonstrates that these exercises have led to significantly improved student learning outcomes tied to these concepts.
232 kr
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Paleoecological data from the Quaternary Period (2.6 million years ago to present) provides an opportunity for educational outreach for the earth and biological sciences. Paleoecology data repositories serve as technical hubs and focal points within their disciplinary communities and so are uniquely situated to help produce teaching modules and engagement resources. The Neotoma Paleoecology Database provides support to educators from primary schools to graduate students. In collaboration with pedagogical experts, the Neotoma Paleoecology Database team has developed teaching modules and model workflows. Early education is centered on discovery; higher-level educational tools focus on illustrating best practices for technical tasks. Collaborations among pedagogic experts, technical experts and data stewards, centered around data resources such as Neotoma, provide an important role within research communities, and an important service to society, supporting best practices, translating current research advances to interested audiences, and communicating the importance of individual research disciplines.
Incorporating Research into Undergraduate Paleontology Courses
Or a Tale of 23,276 Mulinia
Häftad, Engelska, 2018
232 kr
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Research-led, research-oriented, and research-based teaching incorporate research into teaching to different degrees. Research-led teaching focuses on content and informs students about current research findings, while research-oriented teaching focuses on techniques and often occurs in research methods courses. In research-based teaching, students participate in research. Through this involvement, they benefit from improved content knowledge, research skills, and life skills, as well as enhanced personal development. Research-embedded courses can make such benefits available to a wide range of students. Best practices in experiential learning and the incorporation of research in teaching include intentionality, planning, authenticity, reflection, training, monitoring, assessment, and acknowledgment. In this Element, these principles of best practice are illustrated by courses with embedded student research. Guidelines are presented for how to plan and execute a semester-long course-embedded research project, as well as alternative and shorter-term approaches. Research-based teaching provides challenges for students and faculty, but the benefits for all stakeholders are strong.
Utilizing the Paleobiology Database to Provide Educational Opportunities for Undergraduates
Häftad, Engelska, 2018
232 kr
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Integration of research experiences into the undergraduate classroom can result in increased recruitment, retention, and motivation of science students. 'Big data' science initiatives, such as the Paleobiology Database (PBDB), can provide inexpensive and accessible research opportunities. This Element provides an introduction to what the PBDB is, how to use it, how it can be deployed in introductory and advanced courses, and examples of how it has been used in undergraduate research. The PBDB aims to provide information on all fossil organisms, across the tree of life, around the world, and through all of geologic time. The PBDB Resource Page contains a range of PBDB tutorials and activities for use in physical geology, historical geology, paleontology, sedimentology, and stratigraphy courses. As two-year colleges, universities, and distance-based learning initiatives seek research-based alternatives to traditional lab exercises, the PBDB can provide opportunities for hands-on science activities.
232 kr
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The educational benefits of replacing in-class lectures with hands-on activities are clear. Such active learning is a natural fit for paleontology, which can provide opportunities for examining fossils, analyzing data and writing. Additionally, there are a number of topics in the field that are exciting to geology majors and non-majors alike: very few can resist the lure of dinosaurs, huge meteor impacts, vicious Cretaceous sharks or a giant Pleistocene land mammal. However, it can seem difficult to introduce these techniques into a large general education class full of non-majors: paleontological specimens provide a natural starting point for hands-on classroom activities, but in a large class it is not always practical or possible to provide enough fossil material for all students. The Element introduces different types of active learning approaches, and then explains how they have been applied to a large introductory paleontology class for non-majors.
232 kr
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University dinosaur courses provide an influential venue for developing aptitude beyond knowledge of terrestrial Mesozoic reptiles. Passion for dinosaurs, when properly directed, can trigger interest in science and be used to develop critical thinking skills. Examination of dinosaur paleontology can develop competence in information analysis, perception of flawed arguments, recognition of persuasion techniques, and application of disciplined thought processes. Three methods for developing critical thought are outlined in this Element. The first uses dinosaur paleontology to illustrate logical fallacies and flawed arguments. The second is a method for evaluating primary dinosaur literature by students of any major. The final example entails critique of dinosaur documentaries based on the appearance of dinosaurs and the disconnect between scientific fact and storytelling techniques. Students are owed more than dinosaur facts; lecturers should foster a set of skills that equips students with the tools necessary to be perceptive citizens and science advocates.
Equity, Culture, and Place in Teaching Paleontology
Student-Centered Pedagogy for Broadening Participation
Häftad, Engelska, 2020
232 kr
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The diversity crisis in paleontology refers not to modern biota or the fossil record, but rather how our discipline lacks significant representation of individuals varying in race, ethnicity, and other aspects of identity. This Element is a call to action for broadening participation through improved classroom approaches as described in four sections. First, a brief review of the crisis and key concepts are presented. Next, culturally responsive pedagogy and related practices are introduced. Third, specific applications are offered for drawing cultural connections to studying the fossil record. Finally, recommendations including self-reflection are provided for fostering your own cultural competency. Our discipline offers much for understanding earth history and contributing new knowledge to a world impacted by humans. However, we must first more effectively welcome, support, and inspire all students to embrace meaning and value in paleontology; it is critical for securing the future of our field.
Disarticulation and Preservation of Fossil Echinoderms: Recognition of Ecological-Time Information in the Echinoderm Fossil Record
Häftad, Engelska, 2021
232 kr
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The history of life on earth is largely reconstructed from time-averaged accumulations of fossils. A glimpse at ecologic-time attributes and processes is relatively rare. However, the time-sensitive and predictability of echinoderm disarticulation makes them model organisms to determine post-mortem transportation and allows recognition of ecological-time data within paleocommunity accumulations. Unlike many other fossil groups, this has allowed research on many aspects of echinoderms and their paleocommunities, such as the distribution of soft tissues, assessment of the amount of fossil transportation prior to burial, determination of intraspecific variation, paleocommunity composition, estimation of relative abundance of taxa in paleocommunities, determination of attributes of niche differentiation, etc. Crinoids and echinoids have received the most amount of taphonomic research, and the patterns present in these two groups can be used to develop a more thorough understanding of all echinoderm clades.
232 kr
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Recent advances in statistical approaches called phylogenetic comparative methods (PCMs) have provided paleontologists with a powerful set of analytical tools for investigating evolutionary tempo and mode in fossil lineages. However, attempts to integrate PCMs with fossil data often present workers with practical challenges or unfamiliar literature. This Element presents guides to the theory behind and the application of PCMs with fossil taxa. Based on an empirical dataset of Paleozoic crinoids, example analyses are presented to illustrate common applications of PCMs to fossil data, including investigating patterns of correlated trait evolution and macroevolutionary models of morphological change. The authors emphasize the importance of accounting for sources of uncertainty and discuss how to evaluate model fit and adequacy. Finally, the authors discuss several promising methods for modeling heterogeneous evolutionary dynamics with fossil phylogenies. Integrating phylogeny-based approaches with the fossil record provides a rigorous, quantitative perspective on understanding key patterns in the history of life.
232 kr
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Echinoderms have evolved diverse and disparate morphologies throughout the Phanerozoic. Among them, blastozoans, an extinct group of echinoderms that were an important component of Paleozoic marine ecosystems, are primarily subdivided into groups based on the morphology of respiratory structures. However, systematic and phylogenetic research from the past few decades have shown that respiratory structures in blastozoans are not group-defining and they have re-evolved throughout echinoderm evolution. This Element provides a review of the research involving blastozoan respiratory structures, along with research concerning the morphology, paleoecology, and ontogeny of each of the major groupings of blastozoans as it relates to their corresponding respiratory structures. Areas of future research in these groups are also highlighted.
232 kr
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The principles of stratigraphic paleobiology can be readily applied to the nonmarine fossil record. Consistent spatial and temporal patterns of accommodation and sedimentation in sedimentary basins are an important control on stratigraphic architecture. Temperature and precipitation covary with elevation, causing significant variation in community composition, and changes in base level cause elevation to undergo predictable changes. These principles lead to eight sets of hypotheses about the nonmarine fossil record. Three relate to long-term and cyclical patterns in the preservation of major fossil groups and their taphonomy, as well as the occurrence of fossil concentrations. The remaining hypotheses relate to the widespread occurrence of elevation-correlated gradients in community composition, long-term and cyclical trends in these communities, and the stratigraphic position of abrupt changes in community composition. Testing of these hypotheses makes the stratigraphic paleobiology of nonmarine systems a promising area of investigation.
232 kr
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The quantification of morphology through time is a vital tool in elucidating macroevolutionary patterns. Studies of disparity require intense effort but can provide insights beyond those gained using other methodologies. Over the last several decades, studies of disparity have proliferated, often using echinoderms as a model organism. Echinoderms have been used to study the methodology of disparity analyses and potential biases as well as documenting the morphological patterns observed in clades through time. Combining morphological studies with phylogenetic analyses or other disparate data sets allows for the testing of detailed and far-reaching evolutionary hypotheses.
232 kr
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Imaging and visualizing fossils in three dimensions with tomography is a powerful approach in paleontology. Here, the authors introduce select destructive and non-destructive tomographic techniques that are routinely applied to fossils and review how this work has improved our understanding of the anatomy, function, taphonomy, and phylogeny of fossil echinoderms. Building on this, this Element discusses how new imaging and computational methods have great promise for addressing long-standing paleobiological questions. Future efforts to improve the accessibility of the data underlying this work will be key for realizing the potential of this virtual world of paleontology.
The Taphonomy of Echinoids
Skeletal Morphologies, Environmental Factors, and Preservation Pathways
Häftad, Engelska, 2021
232 kr
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The study of echinoid evolution, diversity, and ecology has always suffered from the fact that they are represented by taxa showing widely differing architectural designs of their multi-plated skeletons, inhabiting a large range of marine paleoenvironments, which result in highly varying taphonomic biases dictating their presence and recognition. This Element addresses the taphonomy of echinoids and includes: a general introduction to the morphological features of echinoids that play a role in their preservation; a review of processes which play an important role in the differential preservation of both regular and irregular echinoids including predation and transport; a summary of taphonomic pathways included in actualistic studies for recent sea urchins and then reconstructed for fossil taxa; and finally, a case study of the variation of echinoid taphonomy across a shelf gradient using the rich Miocene echinoid fauna of Sardinia.
Niche Evolution and Phylogenetic Community Paleoecology of Late Ordovician Crinoids
Häftad, Engelska, 2022
232 kr
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Fossil crinoids are exceptionally suited to deep-time studies of community paleoecology and niche partitioning. By merging ecomorphological trait and phylogenetic data, this Element summarizes niche occupation and community paleoecology of crinoids from the Bromide fauna of Oklahoma (Sandbian, Upper Ordovician). Patterns of community structure and niche evolution are evaluated over a ~5 million-year period through comparison with the Brechin Lagerstätte (Katian, Upper Ordovician). The authors establish filtration fan density, food size selectivity, and body size as major axes defining niche differentiation, and niche occupation is strongly controlled by phylogeny. Ecological strategies were relatively static over the study interval at high taxonomic scales, but niche differentiation and specialization increased in most subclades. Changes in disparity and species richness indicate the transition between the early-middle Paleozoic Crinoid Evolutionary Faunas was already underway by the Katian due to ecological drivers and was not triggered by the Late Ordovician mass extinction.