Alosztálya

Alosztálya is a term used in biological classification to denote a rank below class and above order. It is employed to group related organisms within a class that share characteristic features. The use and naming of the rank vary among taxonomic systems: some classifications recognize alosztálya as a standard level, while others omit it or substitute alternative intermediate ranks such as infraclass or superorder. In practice, the criteria for defining a subclass can be based on morphology, development, or genetic data, and the rank may be applied differently across animal, plant, and fungal groups.

Etymology and usage: The word alosztálya derives from Hungarian usage of the Latin term subclassis, reflecting its role as a subdivision within a class. As with many taxonomic ranks, the exact application of alosztálya is not universal and can differ between lineages and historical periods.

Example: A commonly cited historical example is the class Mammalia, which has been divided into subclasses such as Prototheria (egg-laying mammals) and Theria (live-bearing mammals). In some taxonomic schemes, Theria has further subdivisions, like infraclasses Metatheria and Eutheria. These examples illustrate how the rank can help organize evolutionary diversity, even though modern phylogenetic approaches may emphasize clades over fixed hierarchical levels.

In modern taxonomy, the use of alosztálya is less uniform, with many classifications favoring ranks defined by phylogenetic relationships or opting to use higher or lower levels depending on the group. See also taxonomy, classification, phylogeny, and infraclass.