Palaeolama

Palaeolama species were relatives of modern Lamines that lived in the New World from the Pleistocene around 1.9 million years ago to potentially the Holocene epoch around 3,353–4,231 years cal. Before Present (BP).{{Cite journal |last1=Faria |first1=F. H. C. |last2=Carvalho |first2=I. S. |last3=Araújo-Júnior |first3=H. I. |last4=Ximenes |first4=C. L. |last5=Facincani |first5=E. M. |title=3,500 years BP: The last survival of the mammal megafauna in the Americas |year=2025 |journal=Journal of South American Earth Sciences |volume=153 |at=105367 |doi=10.1016/j.jsames.2025.105367 }} Fossil evidence suggests that it had a slender head, elongate snout, and stocky legs.{{Cite book|last=Dompierre|first= H.|title= Observations on the diets of six late Cenozoic North American camelids: Camelops, Hemiauchenia, Palaeolama, Procamelus, Alforjas, and Megatylopus|year= 1995|publisher= National Library of Canada|isbn= 0-612-02748-1|oclc=46500746}}{{Cite book|last1= Fariña|first1= R.A.|url= https://books.google.com/books?id=kUAKgNfiAvoC|jstor= j.ctt16gzd2q|title= Megafauna: Giant Beasts of Pleistocene South America|last2= Vizcaíno|first2= S.F.|last3=De Iuliis|first3= G.|date= 2013|publisher= Indiana University Press|isbn= 978-0-253-00230-3|oclc= 779244424}} They likely weighed around {{Convert|200|kg||abbr=}}Anthony J. Stuart, 2021, Vanished Giants: The Lost World of the Ice Age, "7.19 Llamas: Palaeolama and Hemiauchenia", p.136, University of Chicago Press or up to {{Convert|300|kg||abbr=}}, surpassing the weight of modern llamas. They were specialized forest browsers and are often found in association with early equids, tapirs, deer, and mammoth.{{cite journal|last1= Guérin|first1= C.|last2= Faure|first2= M.|title= Palaeolama (Hemiauchenia) niedae sp. nov. from Northeastern Brazil and its place among the South American Lamini|journal= Geobios|language= fr|volume= 32|issue= 4|year= 1999|pages= 629–659|doi= 10.1016/S0016-6995(99)80012-6}}{{Cite journal|last1= Salas|first1=R.|last2= Stucchi|first2=M.|last3= Devries|first3=T.J.|year= 2003|title=The presence of Plio-Pleistocene Palaeolama sp. (Artiodactyla: Camelidae) on the southern coast of Peru|journal= Bulletin de l'Institut français d'études andines|volume= 32|issue= 2|pages=347–359|doi=10.4000/bifea.6414|doi-access= free}}

Palaeolama had a long, slender skull with an elongated rostrum and robust jaw. This morphology more closely resembles the cranial morphology of Hemiauchenia than that of modern llamas.

The jaw and dental morphology of Palaeolama species distinguish them from other laminae. They tend to have a comparatively more dorsoventrally gracile mandible.{{Cite journal|last= Ruez|first= D.R.|date= 2005-09-30|title= Earliest record of Palaeolama (Mammalia, Camelidae) with comments on "Palaeolama" guanajuatensis|journal= Journal of Vertebrate Paleontology|volume= 25|issue= 3|pages= 741–744|doi= 10.1671/0272-4634(2005)025[0741:eropmc]2.0.co;2|s2cid= 86522528}} Like Hemiauchenia, Palaeolama species lack second deciduous premolars and can further be differentiated by the distinct size and shape of their third deciduous premolars. Their dentition has also been described as more brachyodont-like (short crowns, well-developed roots).

Analyses of their limb elements reveal that they had shorter, stockier metapodials, and longer epipodials, giving them a short, stocky appearance. Limbs such as these are typically associated with organisms adapted to walking on uneven and rugged terrains. This is also suggestive of being well-adapted to avoiding predators in forested areas.

Various dietary analyses have concluded that Palaeolama was a specialized forest browser that relied almost exclusively on plants high in C₃ for subsistence.{{Cite journal |last1=Eltink |first1=Estevan |last2=Castro |first2=Mariela |last3=Montefeltro |first3=Felipe Chinaglia |last4=Dantas |first4=Mario André Trindade |last5=Scherer |first5=Carolina Saldanha |last6=de Oliveira |first6=Paulo Victor |last7=Langer |first7=Max Cardoso |date=March 2020 |title=Mammalian fossils from Gruta do Ioiô cave and past of the Chapada Diamantina, northeastern Brazil, using taphonomy, radiocarbon dating and paleoecology |url=https://linkinghub.elsevier.com/retrieve/pii/S0895981119302354 |journal=Journal of South American Earth Sciences |language=en |volume=98 |pages=102379 |doi=10.1016/j.jsames.2019.102379 |bibcode=2020JSAES..9802379E |access-date=19 April 2024 |via=Elsevier Science Direct|url-access=subscription |hdl=11449/196635 |hdl-access=free }} Additionally, its shallow jaw and brachydont "cheek teeth" are highly suggestive of a mixed or intermediate seasonal diet consisting of primarily leaves and fruits, with some grass.{{Cite journal|last1= Marcolino|first1= C.P.|last2= Isaias|first2= R.M. dos S.|last3= Cozzuol|first3= M.A.|last4= Cartelle|first4= C.|last5= Dantas|first5= M.A.T.|date= 2012|title=Diet of Palaeolama major (Camelidae) of Bahia, Brazil, inferred from coprolites |journal= Quaternary International |volume= 278|pages= 81–86|doi= 10.1016/j.quaint.2012.04.002|bibcode= 2012QuInt.278...81M}}{{Cite journal|last= MacFadden|first= B.J.|date= 2000|title= Cenozoic Mammalian Herbivores From the Americas: Reconstructing Ancient Diets and Terrestrial Communities|journal= Annual Review of Ecology and Systematics |volume= 31|issue= 1|pages= 33–59|doi= 10.1146/annurev.ecolsys.31.1.33|bibcode= 2000AnRES..31...33M}} Microwear analyses further validate this dietary interpretation. Analysis of δ¹³C values from P. major remains in northeastern Brazil confirm it was primarily a consumer of C₃ plant matter.

File:Smilodon stalking Palaeolama.jpg stalking a Palaeolama major group in Brazil]]

As inferred from observations of modern llama, Palaeolama probably organized into bands (consisting of a single male and multiple females) and troops (consisting exclusively of young males sometimes described as "bachelors"). Typically, band territories are defended by resident males, while troops remain more or less free-roaming until they form bands of their own.

File:Pleistocene mammals of Chile.jpg

Fossil evidence suggests Palaeolama was primarily adapted to low-temperate, arid climates and preferred open, forested, and high-altitude mountainous regions.{{Cite journal|last= Scherer|first= C.S.|s2cid= 207195863|year= 2013|title=The Camelidae (Mammalia, Artiodactyla) from the Quaternary of South America: Cladistic and Biogeographic Hypotheses |journal= Journal of Mammalian Evolution |volume= 20|issue= 1|pages= 45–56|doi= 10.1007/s10914-012-9203-4}} The distribution of fossil evidence suggests that they had an altitudinal range limited exclusively by their dietary (vegetation) requirements. Population density is shown to be highly dependent upon access and availability of subsistence resources.{{cite journal |last1=Ruez Jr. |first1=Dennis |title=Earliest Record of Palaeolama (Mammalia, Camelidae) with Comments on "Palaeolama" guanajuatensis |journal=Journal of Vertebrate Paleontology |date=September 30, 2005 |volume=25 |issue=3 |pages=741–744 |doi=10.1671/0272-4634(2005)025[0741:EROPMC]2.0.CO;2 |jstor=4524496 |s2cid=86522528 |url=https://www.jstor.org/stable/4524496 |access-date=22 February 2021|url-access=subscription }}

The origins of this genus are a topic of much debate, as some of the earliest fossils occur during both the Irvingtonian in Florida and the Ensenadan in Uruguay. Despite this, agreement exists amongst paleobiologists on the dispersal of Palaeolama during the Great American Biotic Interchange.{{cite book|chapter= Genetic Analysis of the Origins of Domestic South American Camelids|title= Documenting Domestication: New Genetic and Archaeological Paradigms |jstor= 10.1525/j.ctt1pnvs1.28 |pages= 329–341|author1= Wheeler, J.C.|author2= Chikhi, L.|author3= Bruford, M.W.|year= 2006|publisher= University of California Press|isbn= 9780520246386|citeseerx= 10.1.1.603.88|editor1= Zeder, M.A.|editor2= Bradley, D.G.|editor3= Emshwiller, E.|editor4= Smith, B.D.}} Also, some evidence suggests a move to northern South America during the second of two Pleistocene Camilidae migration events. Fossil evidence ranges from the southern extent of North America (including California, Florida, and Mexico) south through Central America, and terminates in South America (Argentina and Uruguay).

Palaeolama mirifica, the "stout-legged llama", is known from southern California and the Southeastern U.S., with the highest concentration of fossil specimens found in Florida (specifically the counties of Alachua, Citrus, Hillsborough, Manatee, Polk, Brevard, Orange, Sumter, and Levy). Other fossil occurrences have been discovered in Mexico, Central America (El Salvador) and South America (Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador, Paraguay, Peru, Venezuela and Uruguay).{{Cite web|url=https://paleobiodb.org/classic/checkTaxonInfo?taxon_no=52043|title=Fossilworks: Palaeolama mirifica|website=fossilworks.org}}{{Cite web|url=https://www.theguardian.com/science/2020/nov/29/sistine-chapel-of-the-ancients-rock-art-discovered-in-remote-amazon-forest|title = 'Sistine Chapel of the ancients' rock art discovered in remote Amazon forest| website=TheGuardian.com |date = 29 November 2020}}

Palaeolama major, identified by Liais in 1872, lived during the Late Pleistocene and was identified in fossil assemblages from northeastern and northern Brazil, the Pampean region of Argentina and Uruguay, northern Venezuela, and the coastal regions of Ecuador and northern Peru.

Palaeolama wedelli, identified by Gervais in 1855, lived during the Mid- to Late Pleistocene, with fossil specimens found in southern Bolivia and the Andean region of Ecuador.

Climate change, changes and reductions in the types of vegetation on which they relied, and human predation are all hypothesized to have contributed to the extinction of Palaeolama during the Late Pleistocene or Early Holocene. Evidence from both the paleoecological and fossil records suggest that Palaeolama, among other extinct camelids, weathered a number of glacial and interglacial episodes throughout their existence in North and South America. Their disappearance in some regions has been shown to coincide with a change in climate (to warmer, humid conditions) occurring at the end of the Pleistocene (also known as the Late Quaternary warming) suggesting an inability to persevere.{{Cite journal|last1= Barnosky|first1= .D.|last2= Lindsey|first2= E.L.|last3= Villavicencio|first3= N.A.|last4= Bostelmann|first4= E.|last5= Hadly|first5= E.A.|last6= Wanket|first6= J.|last7 =Marshall|first7= C.R.|date=26 October 2015 |title= Variable impact of late-Quaternary megafaunal extinction in causing ecological state shifts in North and South America|journal= Proceedings of the National Academy of Sciences of the United States of America |volume= 113|issue= 4|pages= 856–861|doi= 10.1073/pnas.1505295112|pmid= 26504219|pmc= 4739530|doi-access= free}} This hypothesis is further supported by paleoecological evidence suggesting post-megafaunal extinction shifts in vegetation and whole ecosystems.

{{portal|Paleontology}}

• List of North American animals extinct in the Holocene
• List of South American animals extinct in the Holocene

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Category:Prehistoric camelids

Category:Pleistocene mammals of South America

Category:Prehistoric mammals of North America

Category:Pleistocene Artiodactyla

Category:Prehistoric Artiodactyla genera

Category:Fossil taxa described in 1869

Category:Pliocene Argentina