Jump to ContentJump to Main Navigation
Animal EvolutionInterrelationships of the Living Phyla$
Users without a subscription are not able to see the full content.
Animal Evolution: Interrelationships of the Living Phyla

Claus Nielsen

Print publication date: 2011

Print ISBN-13: 9780199606023

Published to Oxford Scholarship Online: December 2013

DOI: 10.1093/acprof:oso/9780199606023.001.0001

Show Summary Details
Page of

PRINTED FROM OXFORD SCHOLARSHIP ONLINE (oxford.universitypressscholarship.com). (c) Copyright Oxford University Press, 2021. All Rights Reserved. An individual user may print out a PDF of a single chapter of a monograph in OSO for personal use. date: 15 January 2021

CHORDATA

CHORDATA

Chapter:
(p.348) 62 CHORDATA
Source:
Animal Evolution
Author(s):

Claus Nielsen

Publisher:
Oxford University Press
DOI:10.1093/acprof:oso/9780199606023.003.0062

The Chordata is a monophyletic group consisting of three living phyla: Cephalochordata, Urochordata, and Vertebrata. Morphology-based studies on the origin and evolution of the chordates suggested that the segmented and unsegmented urochordates were sister groups. However, most of the newer studies on molecular phylogeny indicate sister-group relationships between the urochordates and vertebrates within the segmented Chordata, implying that the segmentation disappeared in the urochordates. Recent evidence supports the idea that Urochordata and Vertebrata together form the clade Olfactores. The distinguishing feature of the chordates is the notochord, a cylinder of cells surrounded by a strengthened basal membrane.

Keywords:   chordates, Chordata, Cephalochordata, Urochordata, Vertebrata, evolution, urochordates, molecular phylogeny, vertebrates, notochord

Oxford Scholarship Online requires a subscription or purchase to access the full text of books within the service. Public users can however freely search the site and view the abstracts and keywords for each book and chapter.

Please, subscribe or login to access full text content.

If you think you should have access to this title, please contact your librarian.

To troubleshoot, please check our FAQs , and if you can't find the answer there, please contact us .