Kosketellida

Kosketellida is a proposed clade within the eukaryotes that has emerged from recent phylogenomic analyses. It is defined mainly by molecular data, with limited distinguishing morphological traits, and its precise position in the tree of life remains debated.

Taxonomic status and composition are unsettled. Some researchers treat Kosketellida as an independent lineage, while others place it as a subgroup within a larger clade. Because many kosketellids lack clear diagnostic morphology, researchers rely on ribosomal RNA sequences and multi-gene data to delimit membership.

Morphology and biology. Members are typically small and unicellular or colonial, showing diverse cell shapes. They often lack unique, easily recognizable features, making genetic markers essential for identification. Life cycles and ecological roles are not well characterized for most members.

Habitat and distribution. Kosketellida has been reported from marine and freshwater habitats, as well as soils and sediments. The geographic distribution appears broad, but knowledge is incomplete and sampling bias may influence perceived diversity.

Research and significance. The grouping is important for understanding early eukaryotic diversification and the relationships among major lineages. Ongoing genomic, transcriptomic, and ultrastructural studies aim to clarify Kosketellida's position and to illuminate the biology of its constituent organisms.