Macraucheniidae is a family in the extinct South American ungulate

order Order, ORDER or Orders may refer to: * A socio-political or established or existing order, e.g. World order, Ancien Regime, Pax Britannica * Categorization, the process in which ideas and objects are recognized, differentiated, and understood ...

Litopterna Litopterna (from "smooth heel") is an extinction, extinct order of South American native ungulates that lived from the Paleocene to the Pleistocene-Holocene around 62.5 million to 12,000 years ago (or possibly as late as 3,500 years ago), and we ...

, that resembled

camelid Camelids are members of the biological family (biology), family Camelidae, the only currently living family in the suborder Tylopoda. The seven extant taxon, extant members of this group are: dromedary, dromedary camels, Bactrian camels, wild Bac ...

s. They had three functional digits on the fore and hind feet, as well as elongate necks. The family is generally divided up into two subfamilies, Cramaucheniinae (which may be paraphyletic) and Macraucheniinae. The family shows retraction of the nasal region, most extremely to the top of the skull in derived macraucheniine taxa like ''

Macrauchenia ''Macrauchenia'' ("long llama", based on the now-invalid llama genus, ''Auchenia'', from Greek "big neck") is an extinct genus of large ungulate native to South America from the Pliocene or Middle Pleistocene to the end of the Late Pleistocene. I ...

.'' which has been interpreted to have supported a probsocis, perhaps like that of a

saiga antelope The saiga antelope (, ''Saiga tatarica''), or saiga, is a species of antelope which during antiquity inhabited a vast area of the Eurasian steppe, spanning the foothills of the Carpathian Mountains in the northwest and Caucasus in the southwes ...

to filter dust, or a moose-like prehensile lip. The earliest unambiguous members of the family date to the late

Oligocene The Oligocene ( ) is a geologic epoch (geology), epoch of the Paleogene Geologic time scale, Period that extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that defin ...

around 30 million years ago. '' Polymorphis'' from the Eocene has historically been placed as a macraucheniid, but this has been doubted. Most early representatives had a body masses in the range of , though some like ''

Llullataruca ''Llullataruca'' is an extinct genus of macraucheniid litoptern. It lived during the Middle Miocene of what is now Bolivia. Etymology The genus name, ''Llullataruca,'' is derived from the Quechua words ''llulla'' meaning "false", "lie" or "d ...

'' were as small as , and the last representatives of the family from the Pleistocene like ''Macrauchenia'' were over . The family reached its apex of diversity during the late Miocene around 10-6 million years ago, before declining to only a few species belong to the genera ''Macrauchenia'' and ''

Xenorhinotherium ''Xenorhinotherium'' is an extinct genus of macraucheniine macraucheniids, native to northern South America during the Pleistocene and Holocene epoch, closely related to ''Macrauchenia'' of Patagonia. The type species is ''X. bahiense''.

'' by the Late Pleistocene. Below is a phylogenetic tree of the Macraucheniidae, after McGrath ''et al''. 2018:. Cladogram of Macraucheniidae after Lobo, Gelfo & Azevedo (2024):

References

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Phylogeny of Macraucheniidae
{{Taxonbar, from=Q134960 Litopterns Prehistoric mammal families Quaternary mammals of South America Neogene mammals of South America Paleogene mammals of South America Ypresian first appearances Holocene extinctions