At the end of the 20th century, the halberd fern genus, Tectaria, and several related genera were split into a new family, Tectariaceae, containing 8 15 genera and some 230 species.
Some genera were split e.g. Prorocentrum, genus 1 was assigned to those barcodes showing closest similarity to P. levis and P. lima whereas genus 2 was used to denote those barcodes similar to P. micans, P. minimum and P. triestinum.
The converse is true when considering the split genera.
All this suggests that many of these regulatory features of the transcriptomes of Epsilonproteobacteria will have developed after genera have evolutionary split from a common ancestor, and are likely to be in constant flux depending on their ecological niches and its influence on genome reorganisation, mutation frequency and horizontal gene transfer.
More rarely, members of a given species were intermingled with other genera: Psudomonas fluorescens is split by other members of genus Pseudomonas but also the genera Rhodoferax, Polaromonas, Bordetella, and Dechloromonas.
However, in general where we observed well supported taxon splits within genera, these also corresponded to monophyletic species in a combined analysis of a seed-plant alignment of the four coding regions (see Results), suggesting that this source of bias, if it occurs here at all, may be minor.
Second, in order to date the splits within genera, a species-level phylogeny of the two sister genera Isolona (15 out of 20 species) and Monodora (13 out of 14 species) was generated (dataset B, see Additional file 1, treeBASE number SN3633).
Supporting data include details on seed suppliers (Additional file 1), composition of individual carotenoids and tocopherols splitted by genera (Additional file 2) and their percentage of change following domestication (Additional file 4), and ratios of fatty acids to seed dry mass and total oil content (Additional file 3).
Note: Myrica as treated in TJM (1993) split into 2 genera based on Wilbur 1994 Sida 16:93--107.
Bryum may well be the largest genus of mosses in the world with over a thousand described species, but it has been split into segregate genera by Spence (2005).
