''Promacrauchenia'' is an extinct genus of macraucheniids that lived during the Late Miocene to Late Pliocene epochs of what is now
Argentina
Argentina (), officially the Argentine Republic ( es, link=no, República Argentina), is a country in the southern half of South America. Argentina covers an area of , making it the second-largest country in South America after Brazil, th ...
and
Bolivia
, image_flag = Bandera de Bolivia (Estado).svg
, flag_alt = Horizontal tricolor (red, yellow, and green from top to bottom) with the coat of arms of Bolivia in the center
, flag_alt2 = 7 × 7 square p ...
. It belongs to the subfamily
Macraucheniinae
Macraucheniinae is a extinct subfamily of macraucheniids that lived from the Late Miocene and potentially the Early Holocene
The Holocene ( ) is the current geological epoch. It began approximately 11,650 cal years Before Present (), aft ...
, which also includes ''
Huayqueriana
''Huayqueriana'' is an extinct genus of South American litoptern, related to ''Macrauchenia'', and belonging to the same family, Macraucheniidae. It was formerly known as ''Macrauchenidia latidens'', described in 1939 by Cabrera, but redefined as ...
'', ''
Macrauchenia
''Macrauchenia'' ("long llama", based on the now-invalid llama genus, ''Auchenia'', from Greek "big neck") was a large, long-necked and long-limbed, three-toed native South American mammal in the order Litopterna. The genus gives its name to its ...
'', and ''
Xenorhinotherium
''Xenorhinotherium'' is an extinct genus of macraucheniine macraucheniids, closely related to '' Macrauchenia'' of Patagonia. The type species is ''X. bahiense''. Fossils of this genus have been found in the Ituzaingó, Andalhuala, and
Cerro Azul Formation
The Cerro Azul Formation ( es, Formación Cerro Azul), in the Buenos Aires Province also described as Epecuén Formation, is a geological formation of Late Miocene (Tortonian, or Huayquerian in the SALMA classification) age in the Colorado Basin ...
s of Argentina.
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''.
The following cladogram of the Macraucheniidae is based on McGrath ''et al''. 2018, showing the position of ''Promacrauchenia''.