The genus Paramblynotus is the most species-rich genus of the so-called macrocynipoids, the large cynipoid parasitoids of wood-boring and cone-boring insect larvae. The species range in size from some of the largest to the smallest macrocynipoids, comparable in size to microcynipoids. Paramblynotus members occur on all continents except Europe and Australia, with most species being tropical or subtropical. The biology is poorly known but a few observations indicate that the species are parasitoids of beetle larvae. In this monographic revision of the genus, we present a species-level cladistic analysis based on qualitative and quantitative features of the external morphology.

For analysis of quantitative features, we present for the first time a novel coding method, the method of Finite Mixture Coding (FMC) based on k-means clustering, or FMCK. The new method is similar to the FMC method proposed by previous authors in that they both generate codes (character states) for phylogenetic analysis as the direct output of a statistical procedure, thus avoiding the subdivision of quantitative data into discrete states on the basis of arbitrary criteria as with other coding methods. Through incorporating finite mixture analysis and likelihood estimation as used in FMC and k-mean cluster analysis for a priori statistical modeling of component distributions, FMCK is advantageous over FMC in that it can be implemented using readily available statistic programs with k-mean cluster analysis, such as STATISTICA, MINITAB or SYSTAT, available on both PC and Macintosh platforms. We were able to identify 8 quantitative characters among 23 as useful for cladistic analysis by using the new coding method. In total, our character matrix has 132 coded characters.

The phylogenetic analysis indicates that species of the previously recognized genus Decellea form a monophyletic group deeply nested within Paramblynotus. Decellea is therefore synonymized with Paramblynotus, which is separated into seven monophyletic species groups: the virginianus, scaber, yangambicolus, nigricornis, apeosus, ruficollis, and punctulatus groups.

Based on the phylogeny, we reconstruct the historical biogeography of the liopterid subfamily Mayrellinae, consisting of the genera Paramblynotus and Kiefferiella, using dispersal-vicariance analysis in combination with palaeoenvironmental data. The results suggest that the subfamily originated in the Northern Hemisphere and then expanded its distribution early by way of the Bering area. The divergence between Paramblynotus and Kiefferiella was apparently associated with the formation of the Rocky Mountains about 50 million years ago. An early Paramblynotus lineage dispersed to Africa from the eastern Palearctic by way of Arabia, and it subsequently diversified along with montane forests in Africa. The relatively high diversity of Paramblynotus in Southeast Asia is considered to be partly caused by the frequent sea level changes since late Oligocene (29 Ma), which drastically changed the land configuration of this area.

We end this paper with a taxonomic revision of the genus Paramblynotus, with a total of 92 species treated, including 72 described as new and 20 previously known, of which 18 are redescribed. Keys to the species groups as defined in this paper and to all known species of each species