Functional Micromorphology of the Echinoderm Skeleton

Functional Micromorphology of the Echinoderm Skeleton
Author: Przemyslaw Gorzelak
Publisher: Cambridge University Press
Total Pages: 66
Release: 2021-02-11
Genre: Science
ISBN: 110889898X

Echinoderms elaborate a calcite skeleton composed of numerous plates with a distinct microstructure (stereom) that can be modelled into different shapes thanks to the use of a transient amorphous calcium carbonate (ACC) precursor phase and the incorporation of an intraorganic matrix during biomineralization. A variety of different types of stereom microarchitecture have been distinguished, each of them optimized for a specific function. For instance, a regular, galleried stereom typically houses collagenous ligaments, whereas an irregular, fine labyrinthic stereom commonly bears muscles. Epithelial tissues, in turn, are usually associated with coarse and dense stereom microfabrics. Stereom can be preserved in fossil echinoderms and a wide array of investigating methods are available. As many case studies have shown, a great deal of important paleobiological and paleoecological information can be decoded by studying the stereom microstructure of extinct echinoderms.

Molecular Paleobiology of the Echinoderm Skeleton

Molecular Paleobiology of the Echinoderm Skeleton
Author: Jeffrey R. Thompson
Publisher: Cambridge University Press
Total Pages: 120
Release: 2022-12-01
Genre: Science
ISBN: 1009189190

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.

A Review and Evaluation of Homology Hypotheses in Echinoderm Paleobiology

A Review and Evaluation of Homology Hypotheses in Echinoderm Paleobiology
Author: Colin D. Sumrall
Publisher: Cambridge University Press
Total Pages: 91
Release: 2023-04-13
Genre: Science
ISBN: 1009397168

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.

Phylogenetic Comparative Methods: A User's Guide for Paleontologists

Phylogenetic Comparative Methods: A User's Guide for Paleontologists
Author: Laura C. Soul
Publisher: Cambridge University Press
Total Pages: 77
Release: 2021-05-27
Genre: Science
ISBN: 1108897355

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.

Follow the Fossils

Follow the Fossils
Author: Samantha B. Ocon
Publisher: Cambridge University Press
Total Pages: 51
Release: 2021-12-09
Genre: Science
ISBN: 1009177958

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.

Echinoderm Research 2010

Echinoderm Research 2010
Author: Mike Reich
Publisher: Universitätsverlag Göttingen
Total Pages: 147
Release: 2010
Genre:
ISBN: 394187568X

La 4ème de couverture porte : "Echinoderms are a vast group of spiny-skinned animals including starfish, brittle-stars, sea urchins, sand dollars, feather stars, sea lilies and sea cucumbers. These relatives of chordates and hemichordates have inhabited the world's oceans for more than 500 million years. Modern members of the Echinodermata are, with over 7 000 species, an integral part of marine communities from the intertidal to the deep sea. Echinoderms play a major ecological role in marine habitats and are of economic importance in fisheries, aqaculture and biomedicine.The present volume contains the abstracts of lectures and posters presented during the 7th European Conference on Echinoderms (ECE) as well as excursion guides.This year's conference was held at the northern campus of the Georg-August University in Göttingen, Germany, from October 2-9, 2010. More than 100 biologists, palaeontologists and other scientists from 25 countries participated."

Echinoderms Through Time

Echinoderms Through Time
Author: Bruno David
Publisher: CRC Press
Total Pages: 965
Release: 2020-12-17
Genre: Science
ISBN: 1000123677

Echinoderms are now considered as a biological and geological model that underlies researches of primary importance. The extent of the contributions made by the International Echinoderm Conferences to various fields of research is attested by the scope covered by presentation at the international conferences. These proceedings contain the complete papers or abstracts of all the presentations and posters presented at the eighth International Echinoderm Conference, held in Dijon, France in September, 1994. Coverage includes: general; extinct classes; crinoids; asteroids; ophiuroids; holothuroids; and echinoids.

Disarticulation and Preservation of Fossil Echinoderms: Recognition of Ecological-Time Information in the Echinoderm Fossil Record

Disarticulation and Preservation of Fossil Echinoderms: Recognition of Ecological-Time Information in the Echinoderm Fossil Record
Author: William I. Ausich
Publisher: Cambridge University Press
Total Pages: 79
Release: 2021-02-11
Genre: Reference
ISBN: 1108896472

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.

Echinoderm Phylogeny and Evolutionary Biology

Echinoderm Phylogeny and Evolutionary Biology
Author: Christopher R. C. Paul
Publisher: Oxford University Press, USA
Total Pages: 400
Release: 1988
Genre: Language Arts & Disciplines
ISBN:

This unique overview of current research on echinoderm evolution brings together a series of authoritative syntheses and reviews of this diverse marine invertebrate group which includes starfishes and sea urchins. Included in the 26 chapters are molecular biology, biochemistry, developmental biology, comparative anatomy, and palaeontology of the echinoderms.