Protungulatum

Protungulatum
Temporal range: Late Cretaceous - Paleocene, Maastrichtian–Danian

Possible Campanian record

Jaw
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Infraclass: Eutheria
Genus: Protungulatum
Sloan and Van Valen, 1965
Species

Protungulatum ('first ungulate') is an extinct genus of mammal first found in the Bug Creek Anthills in northeastern Montana. The Bug Creek Anthills were initially believed to be Late Cretaceous (latest Maastrichtian) because of the presence of the remains of non-avian dinosaurs and common Cretaceous mammals, but these were later shown to have been reworked[1] from Late Cretaceous strata, and consequently the Bug Creek Anthills are currently believed to be Early Paleocene (Puercan) in age. Remains from the Ravenscrag Formation of Saskatchewan, Canada have been assigned to P. donnae. These remains may also be Cretaceous in age, but the age of the Ravenscrag Formation is not entirely certain. In 2011, remains of a new species of Protungulatum, P. coombsi, from the Hell Creek Formation, which is definitely Late Cretaceous (Maastrichtian) in age, proved that Protungulatum was present in both the Cretaceous and the Paleocene.[2] It was initially assigned to the order condylarthra, a group of archaic "ungulates", that is now known to be polyphyletic. According to Archibald et al. (2011), Protungulatum is not even definitely a placental mammal. Some studies have found it to be close to Cetartiodactyla,[3] but the most recent analysis helds it to be a non-placental eutherian.[4]

The date of divergence of Protungulatum and Placentalia is approximately 75 Ma.[5]

Phylogeny

Cladogram after Gelfo and Sigé, 2011:[6]

Protungulatum

Phenacodus


Kollpaniinae

Simoclaenus

Molinodus

Tiuclaenus

Andinodus

Pucanodus






Didolodontidae

Paulacoutoia

Lamegoia

Paulogervaisia

Didolodus

Ernestokokenia

Escribania chubutensis

Escribania talonicuspis

Raulvaccia

Umayodus








References

  1. ↑ A derived or reworked fossil is a fossil found in rock made significantly later than when the fossilized animal or plant died: it happens when a hard fossil is freed from a soft rock formation by erosion and redeposited in a currently forming sedimentary deposit.
  2. ↑ Archibald, J. David; Zhang, Yue; Harper, Tony; Cifelli, Richard L. (May 6, 2011). "Protungulatum, confirmed Cretaceous occurrence of an otherwise Paleocene eutherian (placental?) mammal" (PDF). Journal of Mammalian Evolution. doi:10.1007/s10914-011-9162-1. Retrieved April 28, 2013.
  3. ↑ J. R. Wible, G. W. Rougier, M. J. Novacek, R. J. Asher 2007. "Cretaceous eutherians and Laurasian origin for placental mammals near the K/T boundary" Nature volume 447: 1003-1006
  4. ↑ Resolving the relationships of Paleocene placental mammals
  5. ↑ Eutherians experienced elevated evolutionary rates in the immediate aftermath of the Cretaceous–Palaeogene mass extinction
  6. ↑ Javier N. Gelfo and Bernard Sigé (2011). "A new didolodontid mammal from the late Paleocene–earliest Eocene of Laguna Umayo, Peru" (PDF). Acta Palaeontologica Polonica. 56 (4): 665–678. doi:10.4202/app.2010.0067.


This article is issued from Wikipedia - version of the 7/10/2016. The text is available under the Creative Commons Attribution/Share Alike but additional terms may apply for the media files.