Proposal for practical multi-kingdom classification of eukaryotes based on monophyly and comparable divergence time criteria

Abstract

Much of the ecological, taxonomic and biodiversity research relies on understanding of phylogenetic relationships among organisms. There are multiple available classification systems that all suffer from differences in naming, incompleteness, presence of multiple non-monophyletic entities and poor correspondence of divergence times. These issues render taxonomic comparisons across the main groups of eukaryotes and all life in general difficult at best. By using the monophyly criterion, roughly comparable time of divergence and information from multiple phylogenetic reconstructions, I propose an alternative classification system for the domain Eukarya to improve hierarchical taxonomical comparability for animals, plants, fungi and multiple protist groups. Following this rationale, I propose 32 kingdoms of eukaryotes that are treated in 10 subdomains. These kingdoms are further separated into 43, 115, 140 and 353 taxa at the level of subkingdom, phylum, subphylum and class, respectively (http://dx.doi.org/10.15156/BIO/587483). Most of the names have been used previously or these were deduced from those of the type taxa to be able to unambiguously link genera to higher taxonomic levels. In the era of phylogenomics, understanding about the phylogenetic relationships among organisms is rapidly increasing. Classifications systems must keep pace with this race to serve the research community by consistent improvements in precision in terms of taxonomic resolution and maintaining monophyly of the ingredient taxa.