of Haemoproteus tartakovskyi has been sequenced. Its genome (23.2 megabases) is similar in size to those of Plasmodium. Its GC-content is 25.4% which is closer to that of P. falciparum (19.3%) than to P. vivax (42.3%). Phylogenetic analyses place it as basal to Plasmodium species. Its inclusion in a phylogenetic tree suggests that the mammalian species are monophytic. A study of 114 mitochondrial genomes from species belonging to four genera - Haemoproteus, Hepatocystis, Leucocytozoon and Plasmodium - has shown that like Plasmodium, Leucocytozoon and Haemoproteus are not monophyletic taxa. The estimated times of the divergence of these genera was after the Cretaceous-Paleogene boundary (about ) and coincided with the evolution of the extant avian orders. The presence of Plasmodium dominicana and the related species Vetufebrus ovatus in Dominican amber suggests that this genus was present after the Cretaceous-Paleogene boundary (about ). Although Poinar has suggested a date of ~, the precise dating of Dominican amber is controversial so an exact date for these species cannot currently be safely assigned. Another study found that Haemoproteus consists of two taxa and that the genus Plasmodium is paraphyletic with respect to Hepatocystis. The same study also found that Plasmodium species of mammals form a well supported clade and this clade was associated with specialization to Anopheles mosquito vectors. The Plasmodium of birds and squamate reptiles all fall within a single clade with evidence for repeated switching between birds and squamate hosts. One study using Bayesian factors to identify the root of the phylogenetic tree has suggested that Plasmodium may be basal to Haemoproteus, Leucocytozoon, Paraheamoproteus and Polychromophilus. This tree also grouped Hepatocystis with Plasmodium. Rayella is thought to have originated from Hepatocystis. A study of the genera Hepatocystis, Nycteria, Plasmodium and Polychromophilus found that Polychromophilus was basal to the other genera and that Plasmodium and Hepatocystis were sister clades. Another study has shown that Parahaemaproteus and Haemoproteus appear to be distinct genera The same study also shown that Nycteria and Hepatocystis lay within the Plasmodium clade. Plasmodium odocoilei was most closely related to genus Polychromophilus. Haemocystidium appeared to be the genus most closely related to Plasmodium. A clade that infect ungulates has been identified. This clade includes species that infect water buffalo (Bubalus bubalis) and goats (Capra aegagrus hircus). The species infecting goats has been named Plasmodium caprae. This clade includes species that infect North American white-tailed deer (Odocoileus virginianus) and African antelopes