IANIGLA   20881
INSTITUTO ARGENTINO DE NIVOLOGIA, GLACIOLOGIA Y CIENCIAS AMBIENTALES
Unidad Ejecutora - UE
artículos
Título:
Systematic revision of Hegetotherium and Pachyrukhos (Hegetotheriidae, Notoungulata) and a new phylogenetic analysis of Hegetotheriidae
Autor/es:
CERDEÑO, E; SEOANE, F.
Revista:
JOURNAL OF SYSTEMATIC PALAEONTOLOGY
Editorial:
CAMBRIDGE UNIV PRESS
Referencias:
Lugar: Cambridge; Año: 2019 vol. 17 p. 1415 - 1443
ISSN:
1477-2019
Resumen:
Hegetotheriidae are one of the most derived familiesof the South American notoungulates, which are known from late Oligocene toPliocene. Several genera of hegetotheriids were described throughout years;most of them have been recently re-examined, but Miocene taxa Hegetotherium and Pachyrukhos were not revised for more than a century. Numerousspecies of both genera were described mainly from the Santa Cruz Formation,Santa Cruz Province, but also from the Colhuehuapian beds in Chubut Province,and the Colloncuran beds in Neuquén and Río Negro provinces, Argentina.Recently, Hegetotherium was recorded inBolivia and Chile. Sinclair was the first reviewer to postulate some synonymiesin the first decade of the XX century. The present contribution provides a revaluationof these genera, including the study of unpublished materials. We conclude thatHegetotherium mirabile and Pachyrukhos moyani are the only hegetotheresin the Santa Cruz Formation (Santacrucian SALMA), and Hegetotherium novum and Pachyrukhospolitus in the Colhuehuapian SALMA. Additionally, H. convexum, H. anceps, H. minum and H. andinum are proposed as synonyms of H. mirabile; H. novum isremoved from Prohegetotherium; and Hegetotherium arctum is excluded fromHegetotheriidae. The taxonomic revision led to perform a new phylogeneticanalysis of Hegetotheriidae, based on a previous data matrix, but enlarged andcorrected, as some taxonomic issues concerning other genera were revealed. The analysissupports the monophyly of the family Hegetotheriidae and the subfamily Pachyrukhinae,as well as the monophyly of genera Hemihegetotheriumand Paedotherium, if the proposed removalof Pd. kakai from the latter is admitted.In contrast, Hegetotheriinae and Hegetotheriumappear paraphyletic. The position of H.novum supports its removal from the genus Prohegetotherium, in which it was recently included.