Pyrotheria

Taxobox
name = Pyrotheria


image_caption = "Pyrotherium romeroi" with the notoungulate "Rhynchippus equinus"
regnum = Animalia
phylum = Chordata
classis = Mammalia
subclassis = Theria
infraclassis = Eutheria
superordo = ?†Meridiungulata
ordo = †Pyrotheria
ordo_authority = Ameghino, 1895
subdivision_ranks = Families
subdivision = †Pyrotheriidae

Pyrotheria is an order of extinct meridiungulate mammals. These mastodon-like ungulates include the genera "Baguatherium", "Carolozittelia", "Colombitherium", "Gryphodon", "Propyrotherium", "Proticia", and "Pyrotherium".cite journal | author = Salas, R., Sánchez, J., and Chacaltana, C. | year = 2006 | title = A new pre-Deseadan pyrothere (Mammalia) from northern Peru and the wear facets of molariform teeth of Pyrotheria | journal = Journal of Vertebrate Paleontology | volume = 26 | issue = 3 | pages = 760–769 | doi = 10.1671/0272-4634(2006)26 [760:ANPPMF] 2.0.CO;2 | doilabel = 10.1671/0272-4634(2006)26[760:ANPPMF]2.0.CO;2]

They had the appearance of large, digitigrade, tapirlike mammals with relatively short, slender limbs and five-toed feet with broad, flat phalanges; restricted to the Paleocene through Oligocene deposits of Brazil and Argentina.

Xenungulata

Some experts place the clade Xenungulata, containing the monospecific genus "Carodnia" within Pyrotheria. The dentition is complete with strong, procumbent, chisel-shaped incisors, strong sharp-pointed canines, and low-crowned cheek teeth with bilophodont molars. The affinities of the Xenungulata remain uncertain. Affinities with the Dinocerata are strongly supported by the dental characteristics. Initial study of the structure of the tarsus suggested that the xenungulates had common ancestry with typical pyrotheres such as "Pyrotherium",cite journal | author = Cifelli, R.L. | year = 1983 | title = Eutherian tarsals from the late Paleocene of Brazil | journal = American Museum Novitates | volume = 2761 | issue = | pages = 1–31] but a more recent examination of the tarsus of "Pyrotherium" failed to support this, instead showing some traits shared by "Pyrotherium" and the Embrithopoda.cite journal | author = Shockey, B.J., and Anaya, F. | year = 2004 | title = "Pyrotherium macfaddeni", sp. nov. (late Oligocene, Bolivia) and the pedal morphology of pyrotheres | journal = Journal of Vertebrate Paleontology | volume = 24 | issue = 2 | pages = 481–488 | doi = 10.1671/2521] It remains to be seen which of these views will turn out to be right. This means that the Pyrotheria can be members of no less than three major cladistic branches of placential mammals: Meridiungulata (if xenungulates are the closest relatives), Laurasiatheria (if dinoceratans are the closest relatives) and Afrotheria (if embrithopods are the closest relatives, which is unlikely).

Classification (including Xenungulata)

*Carodniidae
**"Carodnia"
*Colombitheriidae
**"Proticia"
**"Colombitherium"
*Pyrotheriidae
**"Pyrotherium"
**"Griphodon"
**"Propyrotherium"
**"Carolozittelia"

References: