Taxonomic order

Taxonomic order works differently for plants and animals. The following rules apply:

Animals

Phyla and classes follow a fixed order. The order can be controlled through the management tool. From order downwards, taxa are ordered alphabetically within their parent's scope.

The order of taxon concepts is controlled from the taxon_concepts list page, where you can set the 'taxonomic_position' value; e.g. Animalia will have a value of '1', Chordata '1.1' and Mammalia '1.1.1', which means that when displaying animals the first class is mammals.

It is only possible to set the taxonomic position if the rank of the taxon concept has the fixed_order attribute set (that can be done in the ranks section). NB: ranks also have a taxonomic_position attribute, which is used to validate the taxon concept tree structure (so that it is not possible to create a parent - child link between a genus and a phylum).

All taxon concepts at ranks that do not follow a fixed order are calculated automatically.

Plants

Phyla and classes do not exist; for plants, orders are direct children of the Plantae kingdom. However, within the taxonomic view we display them ordered alphabetically by family (regardless of the order), and further down the tree alphabetically within parent scope. There is no way to control this behaviour from the management tool; in fact this requirement came late in the project, when the only time effective way of implementing this was by creating an alternative calculation routine for plants.

Implementation: the taxonomic positions are recalculated by the rebuild_taxonomy() plpgsql procedure.