Gondwanatheria

Gondwanatheria Temporal range: Campanian-Miocene, 70.6–17.5 Ma PreЄ Є O S D C P T J K Pg N
Mandible of Sudamerica
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Clade:	Synapsida
Class:	Mammalia
Subclass:	Theriiformes
Infraclass:	†Allotheria
Suborder:	†Gondwanatheria Mones, 1987
Subgroups
Family Sudamericidae Bharattherium Gondwanatherium Lavanify Patagonia[1] Sudamerica Vintana Family Ferugliotheriidae Ferugliotherium Trapalcotherium (?) Argentodites Family unknown Greniodon[2] Groeberia[3]

Gondwanatheria is an extinct group of mammals that lived during the Upper Cretaceous through the Miocene in the Southern Hemisphere, including Antarctica. They are known only from isolated teeth, a few lower jaws, two partial skulls and one complete cranium.^[4] Because of this fragmentary knowledge their placement is not clear.

Classification

The affinities of the group are not clear, but gondwanatherians were first interpreted as early xenarthrans, or "toothless" mammals similar to the modern anteater. They were also treated as members of the Multituberculata. The latest thinking is apparently returning towards the xenarthran affinities, or something else entirely. However, a few specimens of gondwanatherians are reclassified as multituberculates.^[5] Recent studies have confirmed their position as allotheres related to multituberculates, possibly even true multituberculates, closer to cimolodonts than "plagiaulacidans" are.^[6][7][8][9]

There are two known families within Gondwanatheria. The family Sudamericidae was named by Scillato-Yané and Pascual in 1984, and includes the genera Sudamerica, Gondwanatherium and Lavanify. The family Ferugliotheriidae was named by José Bonaparte in 1986, and includes one genus, Ferugliotherium.

Further fossils have come from India and Antarctica, where gondwanatherians once lived in the lush forests of the Eocene. Some South American genera, previously considered to be metatherians, are reassigned to Gondwanatheria: the Eocene genus Groeberia and the Miocene (Colhuehuapian) genus Patagonia.^[10]

Taxonomy

Order †Gondwanatheria^[11][12] McKenna 1971 [Gondwanatheroidea Krause & Bonaparte 1993]

• Family †Groeberiidae Patterson, 1952
  • †Groeberia minoprioi Patterson, 1952
  • †Groeberia pattersoni Patterson, 1952
• Family †Ferugliotheriidae Bonaparte 1986
  • †Ferugliotherium windhauseni Bonaparte 1986a [Vucetichia Bonaparte 1990; Vucetichia gracilis Bonaparte 1990]
  • †Trapalcotherium matuastensis Rougier et al. 2008
• Family †Sudamericidae Scillato-Yané & Pascual 1984 [Gondwanatheridae Bonaparte 1986]
  • †Greniodon sylvanicus Goin et al. 2012
  • †Vintana sertichi Krause et al. 2014
  • †Dakshina jederi Wilson, Das Sarama & Anantharaman 2007
  • †Gondwanatherium patagonicum Bonaparte 1986
  • †Sudamerica ameghinoi Scillato-Yané & Pascual 1984
  • †Lavanify miolaka Krause et al. 1997
  • †Bharattherium bonapartei Prasad et al. 2007
  • †Patagonia peregrina Pascual & Carlini 1987

Antarctica

The fact that gondwanatherians were present in Antarctica during the Eocene, while the South American varieties became extinct, indicates that the factors that caused their extinction did not affect Antarctica.^[13] Fossils of gondwanatherians found on Seymour Island (Sudamericidae) show adaptations for a semi-aquatic and perhaps a burrowing way of life, similar to that of living beavers. This suggests an important paleoecological constraint related to dietary preference of this group.^[13] By the end of the Eocene the climate became unsuitable and most of the flora and fauna of Antarctica became extinct. This includes small, arboreal, fruit and insect-eating possums, 10 kg (22 lb) sloths, middle-to-large sized grazers (sparnotheriodontids and Trigonostylops), falcons and ratites.

References

1. Nicolás R. Chimento, Federico L. Agnolin and Fernando E. Novas (2015). "The bizarre ‘metatherians’ Groeberia and Patagonia, late surviving members of gondwanatherian mammals". Historical Biology: An International Journal of Paleobiology 27 (5): 603–623. doi:10.1080/08912963.2014.903945.
2. Francisco J. Goin, Marcelo F. Tejedor, Laura Chornogubsky, Guillermo M. López, Javier N. Gelfo, Mariano Bond, Michael O. Woodburne, Yamila Gurovich, Marcelo Reguero (2012). "Persistence of a Mesozoic, non-therian mammalian lineage (Gondwanatheria) in the mid-Paleogene of Patagonia". Naturwissenschaften 99 (6): 449–463. doi:10.1007/s00114-012-0919-z.
3. Nicolás R. Chimento, Federico L. Agnolin and Fernando E. Novas (2015). "The bizarre ‘metatherians’ Groeberia and Patagonia, late surviving members of gondwanatherian mammals". Historical Biology: An International Journal of Paleobiology 27 (5): 603–623. doi:10.1080/08912963.2014.903945.
4. Kraus, David W. (2014). Vintana Sertichi (Mammalia, Gondwanatheria) from the Late Cretaceous of Madagascar. [Lincoln, NE]: Society of Vertebrate Paleontology. pp. 1–2.
5. Kielan-Jaworowska & Hurum (2001). "Phylogeny and Systematics of multituberculate mammals". Paleontology 44: 389–429. doi:10.1111/1475-4983.00185.
6. Krause, David W.; Hoffmann, Simone; Wible, John R.; Kirk, E. Christopher; Schultz, Julia A.; von Koenigswald, Wighart; Groenke, Joseph R.; Rossie, James B. (2014-11-05). O'Connor, Patrick M., Seiffert, Erik R., Dumont, Elizabeth R., Holloway, Waymon L., Rogers, Raymond R., Rahantarisoa, Lydia J., Kemp, Addison D., Andriamialison, Haingoson. "First cranial remains of a gondwanatherian mammal reveal remarkable mosaicism". Nature (Nature Publishing Group, a division of Macmillan Publishers Limited). online: 512–517. doi:10.1038/nature13922. ISSN 1476-4687.
7. Drake, Nadia (November 5, 2014). "Fossil From Dinosaur Era Reveals Big Mammal With Super Senses". nationalgeographic.com. National Geographic Society. Retrieved November 5, 2014.
8. Wilford, John Noble (November 5, 2014). "Fossil’s Unusual Size and Location Offer Clues in Evolution of Mammals". New York Times. Retrieved November 6, 2014.
9. Nicolás R. Chimento, Federico L. Agnolin and Fernando E. Novas (2015). "The bizarre ‘metatherians’ Groeberia and Patagonia, late surviving members of gondwanatherian mammals". Historical Biology: An International Journal of Paleobiology 27 (5): 603–623. doi:10.1080/08912963.2014.903945.
10. Nicolás R. Chimento, Federico L. Agnolin and Fernando E. Novas (2015). "The bizarre ‘metatherians’ Groeberia and Patagonia, late surviving members of gondwanatherian mammals". Historical Biology: An International Journal of Paleobiology 27 (5): 603–623. doi:10.1080/08912963.2014.903945.
11. Mikko's Phylogeny Archive Haaramo, Mikko (2007). "†Gondwanatheria – gondwanatheres". Retrieved 30 December 2015.
12. Paleofile.com (net, info) . "Taxonomic lists- Mammals". Retrieved 30 December 2015.
13. Reguero, M.A.; Sergio, A.M.; Santillana, S.N. (2002). "Antarctic Peninsula and South America (Patagonia) Paleogene terrestrial faunas and environments: biogeographic relationships". Palaeogeography-Palaeoclimatology-Palaeoecolog 179: 189–210. doi:10.1016/s0031-0182(01)00417-5.

External links

• Mesozoic Mammals - Gondwanatheria