Welcome to the home page for PETRALGA (PErmian & TRiassic ALGAe). This Project was initiated at the end of 1990 in order to provide useful paleontologic tools for both scientific institutions and industry. A website was launched on November 11th, 1999, and this Wiki on January 28th, 2009.
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 about 60 genera and more than 240 species.
Dasycladalean algae have often been consider poor stratigraphic markers. On the contrary, the biostratigraphic value of these calcareous algae is great for they are always present on carbonate platforms where classical markers (Ammonites, etc.) are for the most part absent.
Nevertheless use of this algal group in biostratigraphy had been limited due to a lack of syntheses that collate the information available. On the one hand published work dealing with this Order is exceedingly abundant, but on the other hand it is published in many languages - Russian, German, Japanese, etc. - in journals some of which do not have a wide dissemination.
Assemblages of algae or even some species alone could provide accurate stratigraphic data at the stage or perhaps even the sub-stage level, as has been the case for the Jurassic and Cretaceous systems and the Cenozoic Era.
The specific aims of our sub-project are to set up the mechanism to attain these four fundamental objectives:
- all the parameters (systematics, synonymy, stratigraphic range, palaeogeographic distribution, bibliographic references, etc.);
- international specialists to participate in each of the critical areas (systematics, etc.). One or several contributors are to be in charge of one or more taxa and will be listed as author(s) of their own revision(s);
- provide the first published key for the determination of Permian and Triassic Dasycladalean algae;
- provide a biozonation of the Permian and Triassic periods through the use of these algae.