NDLI: An Evolutionary Scenario For The Origin Of Pentaradial Echinoderms—Implications From The Hydraulic Principles Of Form Determination

Please wait, while we are loading the content...

An Evolutionary Scenario For The Origin Of Pentaradial Echinoderms—Implications From The Hydraulic Principles Of Form Determination

Content Provider	Springer Nature Link
Author	Gudo, Michael
Copyright Year	2005
Abstract	The early evolutionary history of echinoderms was reconstructed on the basis of structural-functional considerations and application of the quasi-engineering approach of ‘Konstruktions-Morphologie’. According to the presented evolutionary scenario, a bilaterally symmetrical ancestor, such as an enteropneust-like organism, became gradually modified into a pentaradial echinoderm by passing through an intermediate pterobranch-like stage. The arms of a pentaradial echinoderm are identified as hydraulic outgrowths from the central coelomic cavity of the bilateral ancestor which developed due to a shortening of the body in length but widening in the diameter. The resulting pentaradial symmetry is a consequence of mechanical laws that dictate minimal contact surface areas among hydraulic pneumatic entities. These developed in the coelomic cavity (metacoel) in the bilaterally symmetrical ancestor, when from the already U-shaped mesentery with the intestinal tract two additional U-shaped bows developed directly or subsequently. During the subsequent development tensile chords of the mesentery ‘sewed’ the gut with the body wall first in three and secondly in five ‘seams’. During the direct development five ‘seams’ between tensile chords and body wall developed straightly. These internal tensile chords subdivide the body coelom into five hydraulic subsystems (‘pneus’), which eventually arrange in a pentaradial pattern. The body could then enlarge only between the tensile chords, which means that five hydraulic bulges developed. These bulges initially supported the tentacles and finally each of them enclosed the tentacle until only the feather-like appendages of the tentacles projected over the surface. The tentacles with their feathers were transformedinto the ambulacral system, and the bulges become the arms. These morphological transformations were accompanied and partly determined by specific histological modifications, such as the development of mutable connective tissues and skeletal elements that fused to ossicles and provided shape stabilization in form of a calcareous skeleton in the body wall. The organism resulted was an ancestral echinoderm (‘Ur-Echinoderm’) with an enlarged metacoel, stabilized by hydraulic pressure working againsta capsule of mutable connective tissue, skeletal elements and longitudinal muscles. In regard to these reconstructions, the body structure of echinoderms can be understood as a hydraulic skeletal capsule.
Starting Page	191
Ending Page	216
Page Count	26
File Format	PDF
ISSN	00015342
Journal	Acta Biotheoretica
Volume Number	53
Issue Number	3
e-ISSN	15728358
Language	English
Publisher	Kluwer Academic Publishers
Publisher Date	2005-01-01
Publisher Place	Dordrecht
Access Restriction	One Nation One Subscription (ONOS)
Subject Keyword	hydraulic principle pentaradial echinoderms engineering morphology body construction Echinodermata Hemichordata Bauplan invertebrate evolution Philosophy of Biology Evolutionary Biology
Content Type	Text
Resource Type	Article
Subject	Philosophy Applied Mathematics Medicine Biochemistry, Genetics and Molecular Biology Environmental Science Agricultural and Biological Sciences

Sl.	Authority	Responsibilities	Communication Details
1	Ministry of Education (GoI), Department of Higher Education	Sanctioning Authority	https://www.education.gov.in/ict-initiatives
2	Indian Institute of Technology Kharagpur	Host Institute of the Project: The host institute of the project is responsible for providing infrastructure support and hosting the project	https://www.iitkgp.ac.in
3	National Digital Library of India Office, Indian Institute of Technology Kharagpur	The administrative and infrastructural headquarters of the project	Dr. B. Sutradhar bsutra@ndl.gov.in
4	Project PI / Joint PI	Principal Investigator and Joint Principal Investigators of the project	Dr. B. Sutradhar bsutra@ndl.gov.in Prof. Saswat Chakrabarti will be added soon
5	Website/Portal (Helpdesk)	Queries regarding NDLI and its services	support@ndl.gov.in
6	Contents and Copyright Issues	Queries related to content curation and copyright issues	content@ndl.gov.in
7	National Digital Library of India Club (NDLI Club)	Queries related to NDLI Club formation, support, user awareness program, seminar/symposium, collaboration, social media, promotion, and outreach	clubsupport@ndl.gov.in
8	Digital Preservation Centre (DPC)	Assistance with digitizing and archiving copyright-free printed books	dpc@ndl.gov.in
9	IDR Setup or Support	Queries related to establishment and support of Institutional Digital Repository (IDR) and IDR workshops	idr@ndl.gov.in

Hydromechanical considerations on the origin of the pentaradial body structure of echinoderms

Cambrian spiral-plated echinoderms from Gondwana reveal the earliest pentaradial body plan

Hydromechanical considerations on the origin of the pentaradial body structure of echinoderms

A hexamer origin of the echinoderms' five rays.

A Fundamental Principle Governing Populations

Data from: Cambrian cinctan echinoderms shed light on feeding in the ancestral deuterostome (Dataset)

Social niche construction and evolutionary transitions in individuality

Kostas Kampourakis: Understanding Evolution

Reproductive cycle of Antedon mediterranea (Crinoidea, Echinodermata): correlation between morphology and physiology

An Evolutionary Scenario For The Origin Of Pentaradial Echinoderms—Implications From The Hydraulic Principles Of Form Determination

Similar Documents

Hydromechanical considerations on the origin of the pentaradial body structure of echinoderms

Cambrian spiral-plated echinoderms from Gondwana reveal the earliest pentaradial body plan

Hydromechanical considerations on the origin of the pentaradial body structure of echinoderms

A hexamer origin of the echinoderms' five rays.

A Fundamental Principle Governing Populations

Data from: Cambrian cinctan echinoderms shed light on feeding in the ancestral deuterostome (Dataset)

Social niche construction and evolutionary transitions in individuality

Kostas Kampourakis: Understanding Evolution

Reproductive cycle of Antedon mediterranea (Crinoidea, Echinodermata): correlation between morphology and physiology

An Evolutionary Scenario For The Origin Of Pentaradial Echinoderms—Implications From The Hydraulic Principles Of Form Determination