Lakukullus
Temporal range: Middle Miocene (Laventan)
~13.8–11.8 Ma
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Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Pilosa
Family: †Nothrotheriidae
Subfamily: †Nothrotheriinae
Genus: †Lakukullus
Pujos et al., 2014
Species:
†L. anatisrostratus
Binomial name
†Lakukullus anatisrostratus
Pujos et al., 2014

Lakukullus is an extinct genus of nothrotheriid ground sloths that lived during the Middle Miocene around 13.8 to 11.8 million years ago of what is now Bolivia.[1]

Etymology

The genus name, Lakukullus, is composed of "Laku’kullu", which means "wild animal of heights" in Aymara, a native Bolivian language, which refers to the locality the specimen was found. The specific name is derived from the Latin word "anatisrostratum", which means "duck beak" in reference to the aspect of the snout appearing physically similar to the bill of an aquatic bird.[1]

Classification

Lakukullus is a genus from the now extinct family of Nothrotheriidae. The Nothrotheriidae are represented by rather medium-sized members of the suborder of sloths, Folivora. Their phylogenetically younger members possessed a dentition reduced by the anterior-most tooth per mandibular arch, diverging from other sloth groups.[2] The Nothrotheriidae, together with the Megatheriidae and with the Megalonychidae, form a more closely related group within the sloths, the superfamily of Megatherioidea. According to the classical view, determined by skeletal anatomy investigations, the Megatherioidea can be considered one of the two major sloth lineages, the second being represented by the Mylodontoidea. With the inclusion of molecular genetic and protein-based studies, a third lineage, the Megalocnoidea, is added. According to the latter studies, the Megatherioidea also include one of the two present-day sloth genera, the three-toed sloths of the genus Bradypus.[3] Thereby, within the Megatherioidea, the Megatheriidae and the Nothrotheriidae are in a sister group relationship,[4] but in part a closer relationship of the Nothrotheriidae with the Megalonychidae is also discussed.[5] Overall, the Nothrotheriidae comprise only about a dozen genera, with their earliest record dating to the Middle Miocene.[1][6] Two subfamilies can be distinguished within the family. Thalassocnus is generally assigned to Thalassocninae as its sole member. The other subfamily is represented by the Nothrotheriinae, which includes, among others, the better known forms of the Pleistocene such as Nothrotherium from South America and Nothrotheriops from North America.[5][7] In addition, Lakukullus is also one of the most basal known members of the subfamily Nothrotheriinae.[8]

Below is a phylogenetic tree of the Nothrotheriinae based on Varela et al. 2019.[8]

Nothrotheriidae 

References

  1. ^ a b c Pujos, François; Iuliis, Gerardo De; Quispe, Bernardino Mamani; Flores, Ruben Andrade (2014). "Lakukullus anatisrostratus , gen. et sp. nov., a new massive nothrotheriid sloth (Xenarthra, Pilosa) from the middle Miocene of Bolivia". Journal of Vertebrate Paleontology. 34 (5): 1243–1248. Bibcode:2014JVPal..34.1243P. doi:10.1080/02724634.2014.849716. hdl:11336/32146. ISSN 0272-4634. S2CID 86724719.
  2. ^ H. Gregory McDonald und Gerardo de Iuliis: Fossil history of sloths. In: Sergio F. Vizcaíno und W. J. Loughry (Hrsg.): The Biology of the Xenarthra. University Press of Florida, 2008, S. 39–55.
  3. ^ Frédéric Delsuc, Melanie Kuch, Gillian C. Gibb, Emil Karpinski, Dirk Hackenberger, Paul Szpak, Jorge G. Martínez, Jim I. Mead, H. Gregory McDonald, Ross D.E. MacPhee, Guillaume Billet, Lionel Hautier und Hendrik N. Poinar: Ancient mitogenomes reveal the evolutionary history and biogeography of sloths. Current Biology 29 (12), 2019, S. 2031–2042, doi:10.1016/j.cub.2019.05.043
  4. ^ Gaudin, Timothy J. (2004). "Phylogenetic relationships among sloths (Mammalia, Xenarthra, Tardigrada): the craniodental evidence". Zoological Journal of the Linnean Society. 140 (2): 255–305. doi:10.1111/j.1096-3642.2003.00100.x. ISSN 1096-3642. S2CID 38722942.
  5. ^ a b de Muizon, C.; McDonald, H. G.; Salas-Gismondi, R.; Schmitt, M. U. (2004). "The youngest species of the aquatic sloth Thalassocnus and a reassessment of the relationships of the nothrothere sloths (Mammalia: Xenarthra)". Journal of Vertebrate Paleontology. 24 (2): 387–397. Bibcode:2004JVPal..24..387D. doi:10.1671/2429a. S2CID 83732878. Archived from the original on 12 October 2018.
  6. ^ Gaudin, Timothy J.; Boscaini, Alberto; Mamani Quispe, Bernardino; Andrade Flores, Rubén; Fernández-Monescillo, Marcos; Marivaux, Laurent; Antoine, Pierre-Olivier; Münch, Philippe; Pujos, François (2022-05-24). "Recognition of a new nothrotheriid genus (Mammalia, Folivora) from the early late Miocene of Achiri (Bolivia) and the taxonomic status of the genus Xyophorus". Historical Biology. 35 (6): 1041–1051. doi:10.1080/08912963.2022.2075744. ISSN 0891-2963. S2CID 258688117.
  7. ^ De Iuliis, Gerardo; Gaudin, Timothy J.; Vicars, Matthew J. (January 2011). "A new genus and species of nothrotheriid sloth (Xenarthra, Tardigrada, Nothrotheriidae) from the Late Miocene (Huayquerian) of Peru: NEW LATE MIOCENE NOTHROTHERIID SLOTH FROM PERU". Palaeontology. 54 (1): 171–205. Bibcode:2011Palgy..54..171D. doi:10.1111/j.1475-4983.2010.01001.x. S2CID 55321577.
  8. ^ a b Varela, Luciano; Tambusso, P Sebastián; McDonald, H Gregory; Fariña, Richard A (2019-03-01). "Phylogeny, Macroevolutionary Trends and Historical Biogeography of Sloths: Insights From a Bayesian Morphological Clock Analysis". Systematic Biology. 68 (2): 204–218. doi:10.1093/sysbio/syy058. ISSN 1063-5157. PMID 30239971.
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