Litopterna

Mounted skeleton of Macrauchenia patachonica (larger mount) alongside Phenacodus primaevus, copyright Ryan Somma.

Belongs within: Panameriungulata.

The Litopterna are a group of more or less cursorial herbivores known from the late Palaeocene to the Pleistocene of South America. Distinguishing features of the group include fusion of the mandibular symphysis, and characters of the tarsal bones (Muizon & Cifelli 2000).

<==Litopterna
    |--Neocaliphrium recens FS15
    `--+--Xenorhinotherium bahiense FS15
       `--Macrauchenia Owen 1838 FS15, D07
            `--M. patachonica FS15

Litopterna incertae sedis:
  Miguelsoria parayirunhor (Paula Couto 1952) [=Ernestokokenia parayirunhor] MC00
  Proectocion argentinus MC00
  Requisia vidmari MC00
  Polymorphis MC00
  Cramauchenia MC00
  Proadiantus MC00
  Protolipterna [Protolipternidae] MC00
    `--P. ellipsodontoides Cifelli 1983 MC00
  Thoatherium Ameghino 1887 D07
    `--T. minisculum D07
  Asmithwoodwardia Paula Couto 1952 MC00
    |--A. scotti Paula Couto 1952 MC00
    `--A. subtrigona MC00
  Diadiaphorus Ameghino 1887 D07
    |--D. caniadensis D07
    |--D. majusculus D07
    `--D. zamius D07
  Theosodon Ameghino 1887 D07
    |--T. garretorum D07
    |--T. gracilis D07
    |--T. lydekkeri D07
    `--T. tontanus D07

*Type species of generic name indicated

REFERENCES

[D07] Dixon, D. 2007. The Complete Illustrated Encyclopedia of Dinosaurs & Prehistoric Creatures. Hermes House: London.

[FS15] Faurby, S., & J.-C. Svenning. 2015. A species-level phylogeny of all extant and late Quaternary extinct mammals using a novel heuristic-hierarchical Bayesian approach. Molecular Phylogenetics and Evolution 84: 14–26.

[MC00] Muizon, C. de, & R. L. Cifelli. 2000. The “condylarths” (archaic Ungulata, Mammalia) from the early Palaeocene of Tiupampa (Bolivia): Implications on the origin of the South American ungulates. Geodiversitas 22 (1): 47–150.