Topic
Alcidedorbignya
About: Alcidedorbignya is a research topic. Over the lifetime, 2 publications have been published within this topic receiving 97 citations.
Papers
TL;DR: One of the major aims of this analysis is to test possible close phylogenetic relationships of Alcidedorbignya inopinata with the five orders of South American “ungulates”, and sheds light on the cranial anatomy of placentals from the earliest Paleocene.
Abstract: Alcidedorbignya inopinata Muizon & Marshall, 1987 is a basal pantodont (Placentalia, Mammalia) of small body size, from the early Palaeocene of the Santa Lucia Formation at Tiupampa, Bolivia. Tiupampa is the type locality for the Tiupampan, a South American Land Mammal age (SALMA), which is assigned an age equivalent to the basal Torrejonian 1 of North America (c. 65 Ma). Alcidedorbignya is known by exceptionally preserved specimens, which are described here. The two major specimens are an almost complete skeleton (MHNC 8372) and a partial skull (MHNC 8399), the former representing one of the best-preserved fossil placentals from the early Palaeocene and probably the oldest placental skeleton that is so completely known. These specimens are also the first eutherian skulls and skeleton ever discovered at Tiupampa, a locality which has yielded numerous metatherian skulls and partial skeletons. The remarkable preservation of the two skulls allows a detailed description of the cranial anatomy with we...
106 citations
1 Jan 1992
TL;DR: Alcidedorbignya inopinata as discussed by the authors is a primitive pantodont from the Early Paleocene of Tiupampa, Department of Cochabamba, in the “Cordillera Oriental” of south-central Bolivia.
Abstract: Alcidedorbignya inopinata Muizon and Marshall is a primitive pantodont from the Early Paleocene of Tiupampa, Department of Cochabamba, in the “Cordillera Oriental” of south-central Bolivia. It is known by almost complete upper and lower dentitions, which are described in detail. The occurrence of abundant juvenile specimens allows a study of tooth replacement. The molars of Alcidedorbignya inopinata are primitive for a pantodont but they show the characteristic synapomorphy of the group, which is the presence of a V-shaped ectoloph of P3-4. However, the paracone and the metacone of A. inopinata are separated at their bases, a feature absent in the Bemalambdidae and Harpyodus , which have connate to semi-connate paracone and metacone. Because of this character, A. inopinata , although the oldest, is not the most primitive pantodont. However, A. inopinata , as in bemalambdids and Harpyodus , does not have a mesostyle on M1-2/ or a strongly V-shaped centrocrista, which are found in all other pantodonts. For this reason, Alcidedorbignya inopinata is removed from the Pantolambdidae (which are too specialized) and referred to the new monotypic family Alcidedorbignyidae. The family Wangliidae Van Valen, 1988, is not accepted here and the genus Wanglia is regarded as a junior synonym of Harpyodus ; the latter includes the two species H. euros and H. decorus. Analysis of pantodont origins leads to the conclusion that didelphodontines constitute the best potential sister-group; however, no synapomorphy could be found to substantiate this hypothesis. Alcidedorbignya inopinata is the first pantodont known from a southern continent and, being the oldest, it raises a discussion on the paleobiogeographic history of the group.
32 citations
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Performance Metrics
| Year | Papers |
|---|---|
| 2015 | 1 |
| 1992 | 1 |