Promacrauchenia

Promacrauchenia is an extinct genus of macraucheniids that lived during the Late Miocene to Late Pliocene epochs of what is now Argentina and Bolivia. It belongs to the subfamily Macraucheniinae, which also includes Huayqueriana, Macrauchenia, and Xenorhinotherium.^[1][2][3] Fossils of this genus have been found in the Ituzaingó, Andalhuala, and Cerro Azul Formations of Argentina.

Promacrauchenia Temporal range: Late Miocene-Pliocene (Huayquerian-Uquian) ~6.8–3.0 Ma PreꞒ Ꞓ O S D C P T J K Pg N ↓
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	†Litopterna
Family:	†Macraucheniidae
Subfamily:	†Macraucheniinae
Genus:	†Promacrauchenia Ameghino, 1904
Type species
†Promacrauchenia antiqua Ameghino, (1889)
Other species
†P. calchaquiorum Rovereto, 1914
Synonyms
Macrauchenia antiqua Ameghino 1889

Classification

The genus Promacrauchenia was first described by Florentino Ameghino in 1904, on the basis of fossils found in Patagonia in lower Pliocene deposits and which Ameghino himself, years earlier, had described as a species of Macrauchenia, as M. antiqua . In addition to the type species, Promacrauchenia antiqua, other species have been assigned to this genus: P. calchaquiorum, P. chapadmalense, P. ensenadense, P. kraglievichi and P. yepesi.

Promacrauchenia was a member of the Macraucheniidae, a group of litopterns whose evolution led to the development of camel-like forms with strange nasal bones. Promacrauchenia, in particular, was a specialized macraucheniid, perhaps directly ancestral to genera such as Macrauchenia and Windhausenia.^[3]

The following cladogram of the Macraucheniidae is based on McGrath et al. 2018, showing the position of Promacrauchenia.^[4]

Proadiantus excavatus Tricoelodus spp. Macraucheniidae  Polymorphis lechei Pternoconius spp. Cramauchenia normalis Coniopternium Llullataruca shockeyi Theosodon spp. Theosodon arozquetai Macraucheniinae  Scalabrinitherium bravardi Huayqueriana cristata Huayqueriana cf. cristata Oxyodontherium zeballosi Paranauchenia hystata Paranauchenia denticulata Cullinia levis Promacrauchenia calchaquiorum Promacrauchenia antiqua Windhausenia delacroixi Xenorhinotherium bahiense Macraucheniopsis ensenadensis Macrauchenia patachonica

References

1. "Fossilworks: Promacrauchenia". www.fossilworks.org. Retrieved 2022-04-29.
2. Schmidt, Gabriela I.; Ferrero, Brenda S. (2014-07-29). "Taxonomic reinterpretation of Theosodon hystatus Cabrera and Kraglievich, 1931 (Litopterna, Macraucheniidae ) and phylogenetic relationships of the family". Journal of Vertebrate Paleontology. 34 (5): 1231–1238. Bibcode:2014JVPal..34.1231S. doi:10.1080/02724634.2014.837393. hdl:11336/18953. ISSN 0272-4634. S2CID 86091386.
3. Analía M. Forasiepi; Ross D. E. MacPhee; Santiago Hernández del Pino; Gabriela I. Schmidt; Eli Amson; Camille Grohé (2016). "Exceptional skull of Huayqueriana (Mammalia, Litopterna, Macraucheniidae) from the late Miocene of Argentina: anatomy, systematics, and paleobiological implications" (PDF). Bulletin of the American Museum of Natural History. 404: 1–76. doi:10.1206/0003-0090-404.1.1. hdl:2246/6659. S2CID 89219979.
4. Andrew J. McGrath; Federico Anaya; Darin A. Croft (2018). "Two new macraucheniids (Mammalia: Litopterna) from the late middle Miocene (Laventan South American Land Mammal Age) of Quebrada Honda, Bolivia". Journal of Vertebrate Paleontology. 38 (3): e1461632. Bibcode:2018JVPal..38E1632M. doi:10.1080/02724634.2018.1461632. S2CID 89881990.