Under Construction

Pituriaspidagroup is extinct

Philippe Janvier
Click on an image to view larger version & data in a new window
Click on an image to view larger version & data in a new window
Containing group: Vertebrata

Introduction

The Pituriaspida are a small group of fossil, armored jawless vertebrates, only known by two genera, Pituriaspis and Neeyambaspis, from the late Early Devonian or early Middle Devonian (about 390 million years) of Queensland, Australia. The best documented form, however, is only Pituriaspis, which resembles the Osteostraci, although devoid of any median dorsal nasohypophysial opening. The nasal or nasohypophysial opening is supposed to lie ventrally, anteriorly to the mouth. The headshield of Pituriaspis shows a ventral oralobranchial chamber, as in the Osteostraci and Galeaspida, a long anterior rostral process, and two lateral cornual processes which bound anteriorly the area for the attachment of the paired fins. The headshield extends posteriorly to form a long abdominal division which probably reached the anal region.

Pituriaspids lived in a marine, deltaic environment, along with various placoderms.

Characteristics

The only unique characteristic of the Pituriaspida is a peculiar pit, of unknown function, ventrally to the orbits.

References

Janvier, P. (1996). Early vertebrates. Oxford Monographs in Geology and Geophysics, 33, Oxford University Press, Oxford.

Young, G. C. (1991). The first armoured agnathan vertebrates from the Devonian of Australia. In Early vertebrates and related problems of evolutionary biology (ed. M. M.Chang, Y. H. Liu, and G. R. Zhang), pp. 67-85. Science Press, Beijing.

Title Illustrations
Click on an image to view larger version & data in a new window
Click on an image to view larger version & data in a new window
Scientific Name Pituriaspis
Location Australia
Comments Pituriaspids are mainly known by Pituriaspis, from the Devonian of Australia. As a whole, their headshield is quite similar to that of osteostracans, though devoid of a naso-hypophysial opening. The mouth, gill openings and presumably the nasal aperture were all situated on the ventral side of the head. Well-developed paired fins attached on either sides of the headshield. The only diagnostic feature of pituriaspids is an enigmatic pit adjacent to the eyes.
Reference based on Young, G. C. (1991). The first armoured agnathan vertebrates from the Devonian of Australia. In Early vertebrates and related problems of evolutionary biology (ed. M. M. Chang, Y. H. Liu, and G. R. Zhang), pp. 67-85. Science Press, Beijing.
Specimen Condition Fossil -- Period: Devonian
Image Use creative commons This media file is licensed under the Creative Commons Attribution License - Version 3.0.
Copyright © 1997
About This Page


Muséum National d'Histoire Naturelle Paris, France

Page: Tree of Life Pituriaspida. Authored by Philippe Janvier. The TEXT of this page is licensed under the Creative Commons Attribution License - Version 3.0. Note that images and other media featured on this page are each governed by their own license, and they may or may not be available for reuse. Click on an image or a media link to access the media data window, which provides the relevant licensing information. For the general terms and conditions of ToL material reuse and redistribution, please see the Tree of Life Copyright Policies.

Citing this page:

Janvier, Philippe. 1997. Pituriaspida. Version 01 January 1997 (under construction). http://tolweb.org/Pituriaspida/14841/1997.01.01 in The Tree of Life Web Project, http://tolweb.org/

edit this page
close box

This page is a Tree of Life Branch Page.

Each ToL branch page provides a synopsis of the characteristics of a group of organisms representing a branch of the Tree of Life. The major distinction between a branch and a leaf of the Tree of Life is that each branch can be further subdivided into descendent branches, that is, subgroups representing distinct genetic lineages.

For a more detailed explanation of the different ToL page types, have a look at the Structure of the Tree of Life page.

close box

Pituriaspida

Page Content

articles & notes

collections

people

Explore Other Groups

random page

  go to the Tree of Life home page
top