A new dentition-based phylogeny of Litopterna (Mammalia: Placentalia) and ‘archaic’ South American ungulates
Year: 2024
Type: article
Abstract: Ever since the discovery of Macrauchenia patachonica by Charles Darwin in 1834, the affinities of litopterns—a group of extinct South American Native Ungulates (SANUs)—have been elusive. In particular, the interfamilial relationships and timing of the familial diversification within the order Litopterna have not been addressed with adequate taxon and character sampling, and modern phylogenetic methods. We address these issues using a new morphological matrix of 703 dental and mandibular characters, scored for the earliest litopterns alongside early SANUs of other orders (Astrapotheria, Notoungulata, Pyrotheria, and Xenungulata). We also included members of families that have been often included within Litopterna, such as Didolodontidae, Protolipternidae, Indaleciidae, and Notonychopidae, the last two sometimes grouped in the order Notopterna. We conducted maximum parsimony and undated and tip-dated Bayesian phylogenetic analyses. Our results indicate that (1) didolodontids, protolipternids, and kollpaniines should be considered early SANUs, but not particularly closely related to any order, (2) Indaleciidae and Notonychopidae usually form a monophyletic group (Notopterna), and (3) Litopterna is a monophyletic unit composed of four families [Adianthidae, Anisolambdidae (subfamilies Anisolambdinae and Sparnotheriodontinae), Macraucheniidae, Proterotheriidae], and tentatively the notoptern families Indaleciidae and Notonychopidae with a probable origin ~64.0 Mya in the Early Palaeocene.
Language: English
Subfield: Paleontology
Field: Earth and Planetary Sciences
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $3,604
Awards: Collaborative Research: testing the link between climate and mammalian faunal dynamics in the early Paleocene record of the San Juan Basin, New Mexico, Collaborative Research: A Phylogeny of Placental Mammals based on Paleocene Taxa: Determining the Impact of the K-Pg Extinction on Mammalian Evolutionary History, Collaborative Research: A Phylogeny of Placental Mammals based on Paleocene Taxa: Determining the Impact of the K-Pg Extinction on Mammalian Evolutionary History
OpenAlex ID: W4402332197