There are two genera, Mesitornis (2 species) and Monias (subdesert mesite).

Genus Monias Oustalet & Grandidier, 1903
Subdesert mesite Monias benschi Oustalet & Grandidier, 1903
Genus Mesitornis Bonaparte, 1855 [Mesites Geoffroy, 1838 non Schoenherr, 1838; Mesoenas Reichenbach, 1861]
White-breasted mesite, Mesitornis variegata (Saint-Hilaire, 1838)
Brown mesite, Mesitornis unicolor (Des Murs, 1845)
Historically, mesites have been allied with the doves and the dippers.
While the latter is certainly incorrect, there is some indication that they might indeed be closer (though not very close) to the Columbiformes.
The purported gruiforms kagu and sunbittern (and possibly the extinct adzebills too) might also be not-too-distant relatives.
These latter taxa, remarkably, were all only tentatively placed in the Gruiformes, and are apparently all of Gondwanan origin; like the mesites, the kagu and sunbittern are among the rather few birds possessing powder down.
Still, the data hinting at a possible relationship between the "odd gruiforms" (and possibly pigeons) is by no means robust enough to draw a firm conclusion. (
Fain & Houde 2004) Arguably, they might be considered an order of their own (Mesitornithiformes) as has on occasion been done in the past, but unlike with the hoatzin, little phylogenetic research has yet been conducted on mesites.

The DNA study of Hackett et al. (
2008) suggested that the mesites are a sister group of the doves, somewhat more distantly related to the sandgrouse, tropicbirds, grebes, and flamingos, within the proposed "Metaves" clade.
Other researchers have been unable to confirm the "Metaves".

Recent phylogenomic studies support the grouping of mesites, sandgrouse and pigeons forming the sister taxon to Mirandornithes.
There are two genera, Mesitornis (2 species) and Monias (subdesert mesite).
Genus Monias Oustalet & Grandidier, 1903
Subdesert mesite Monias benschi Oustalet & Grandidier, 1903
Genus Mesitornis Bonaparte, 1855 [Mesites Geoffroy, 1838 non Schoenherr, 1838; Mesoenas Reichenbach, 1861]
White-breasted mesite, Mesitornis variegata (Saint-Hilaire, 1838)
Brown mesite, Mesitornis unicolor (Des Murs, 1845)
Historically, mesites have been allied with the doves and the dippers. While the latter is certainly incorrect, there is some indication that they might indeed be closer (though not very close) to the Columbiformes. The purported gruiforms kagu and sunbittern (and possibly the extinct adzebills too) might also be not-too-distant relatives. These latter taxa, remarkably, were all only tentatively placed in the Gruiformes, and are apparently all of Gondwanan origin; like the mesites, the kagu and sunbittern are among the rather few birds possessing powder down. Still, the data hinting at a possible relationship between the "odd gruiforms" (and possibly pigeons) is by no means robust enough to draw a firm conclusion. (Fain & Houde 2004) Arguably, they might be considered an order of their own (Mesitornithiformes) as has on occasion been done in the past, but unlike with the hoatzin, little phylogenetic research has yet been conducted on mesites.
The DNA study of Hackett et al. (2008) suggested that the mesites are a sister group of the doves, somewhat more distantly related to the sandgrouse, tropicbirds, grebes, and flamingos, within the proposed "Metaves" clade. Other researchers have been unable to confirm the "Metaves".
Recent phylogenomic studies support the grouping of mesites, sandgrouse and pigeons forming the sister taxon to Mirandornithes.
Mesite