Welcome to the home page of PETRALGA (PErmian & TRiassic ALGAe). This site is still under construction. Consequently, for the moment the best way to explore it is to take a look at recent updates in What's New! and use the links there to navigate to other pages. We would welcome a message in our Guestbook or in a posting to the Newsgroup CALCALGA.

Would you like to find other sites dedicated to algae? Fossil and Modern Algae, a Webring, will help you; you can also visit the pages of the International "Fossil Algae" Association.

The Project was initiated late in 1990 in order to provide paleontological tools useful to both Scientific Institutions and Industry.

As the first main project, an exhaustive catalogue of Dasycladalean algae from the Permian and Triassic systems is in preparation, for these periods were the apogee of this Order with some 60 genera and more than 240 species known.

Dasycladalean algae have been thought to be poor stratigraphic markers. On the contrary, they have a great biostratigraphic value for they are always present on carbonate platforms where the classical markers (Ammonites, etc.) are absent.

But the use of this algal group in biostratigraphy has been limited due to a lack of syntheses. Although published work on these plants is most abundant, it is relatively inaccessible for it is in many languages (Russian, German, Japanese, etc.), in publications with limited distribution.

Assemblages of algae or sometimes even a single species can provide precise stratigraphic identification at the stage or even sub-stage level, as has been accomplished already for the Jurassic, Cretaceous and Tertiary period.

Several years ago a catalogue was compiled for Jurassic and Cretaceous algal species by the Société Nationale ELF-Aquitaine (Production). Although this work is copiously illustrated, it is merely a compilation of descriptions and diagnoses with no critical analyses (synonymy, etc.).

A special publication of Géobios [BASSOULLET et alii, 1978], "Les Algues Dasycladales du Jurassique et du Crétacé. Révision critique", provides the data omitted by the earlier compilation. But because it was published "for profit" it is not well illustrated; in addition, it does not include the species found subsequently.

Consequently, a key to the determination of species is not available in existing literature.

Therefore, the project aims to provide complete coverage of the following:

  • all of the parameters required for the scientific determination of each species (systematics, synonymy, stratigraphic range, paleogeographic distribution, etc.) will be provided;

  • internationally recognized specialists will be consulted for each of the critical areas (systematics, etc.). One or several contributors will be in charge of one or more taxa and will be mentioned as author(s) of their revision(s);

  • the first key to the determination of Permian and Triassic Dasycladalean algae will become available;

  • a biozonation of the Permian and Triassic periods through the identification of algae will become feasible.


What's New!

The following is a list of recent additions to and modifications of our web site. Whenever we add or change something, we shall note it here. The most recent changes are listed first, and each item in the list is linked to the updated page.

December 22, 2004

  • It took a little time (more than 3 years) but ... here we are again: a new start with a brand new format (based on CSS and Frames).
    [Special thanks are due to Miguel V. Pardo Alonso and Paleopolis for hosting facilities]

September 2000

August 2000

June 2000

March 2000

February 2000

January 2000

December 1999


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Launched Nov. 11, 1999
Last modified May 08, 2007
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