A Review And Evaluation Of Homology Hypotheses In Echinoderm Paleobiology

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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.

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Genre : Science
Author : Colin D. Sumrall
Publisher : Cambridge University Press
Release : 2023-04-13
File : 91 Pages
ISBN-13 : 9781009397162


The Ecology Of Biotic Interactions In Echinoids

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This Element reviews the ecologies of skeletal trace-producing interactions on echinoids in Modern ecosystems and the recognition of those biogenic traces in the fossil record. This title is also available as Open Access on Cambridge Core.

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Genre : Reference
Author : Elizabeth Petsios
Publisher : Cambridge University Press
Release : 2023-10-31
File : 88 Pages
ISBN-13 : 9781108899840


The Origin Of Higher Taxa

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This text discusses whether the origin of radically new kinds of organisms - new higher taxa - are the result of normal Darwinian evolution proceeding, or whether unusual genetic processes and/or special environmental circumstances are necessary.

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Genre : Science
Author : T. S. Kemp
Publisher : University of Chicago Press
Release : 2016
File : 215 Pages
ISBN-13 : 9780226335957


Evolutionary Theory

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Genre : Evolution
Author :
Publisher :
Release :
File : 426 Pages
ISBN-13 : UCSD:31822006505341