Camels and Llamas
after the flood

Camel and llama biogeography

Chad Arment (2023)

Vicuña in Chile (Allesandro Caproni, CC BY 2.0)

I should first note that, compared to some of the animal groups I’ve looked at over the last couple of years, camels and kin may be overdue for a detailed phylogenetic evaluation from the secular side. There have been a few papers in the last decade discussing specific subfamilies, but rarely anything more extensive. This means that certain genera may be placed in different relationships by different authors, or that some subfamilies will not necessarily be recognized by all authors. Here, I will stick primarily to the subfamilies noted in Honey et al. (1998).

The Family Camelidae belongs to the suborder Tylopoda, within the order Artiodactyla. These are even-toed ungulates. (Biblically, they are considered unclean animals because while they ‘chew the cud’ they do not have a cloven hoof.) Evolutionists believe that camelids evolved in North America, along with some other (but not all) tylopid families like the Oromerycidae (six Eocene genera), probably from an ancestral Asian immigration event (Janis et al. 1998). The ‘earliest’ artiodactyl is the very early Eocene Diacodexis, found in North America, Europe, and South Asia (Halliday et al. 2017).

The first camelids show up in Upper Eocene deposits of North America, with a few more appearing in the Oligocene, then extensive radiation during the Miocene (Honey et al. 1998). During the Late Miocene, camels emigrated across Beringia to Asia and into Africa and Europe. After the land bridge to South America opened up (the Great American Biotic Interchange), camelids began appearing there in the Late Pliocene (Gasparini et al. 2017).

Bactrian camel, China (David Stanley, CC BY 2.0)

The main subfamily to appear in North America is the Camelinae, from which two main tribes diverged, the Camelini and the Aucheniini (also known as the Lamini), probably during the early Miocene (Heintzman et al. 2015). Both groups eventually spread outside North America (and will be discussed further below). There were several other subfamilies, though, that appeared only in North America.

The Stenomylinae were small, gracile camelids that grazed the open grasslands. They have been called “gazelle camels,” roughly similar in size and appearance. Six genera are known from Oligocene and Miocene deposits (Frick and Taylor 1968; Constenius and Dawson 2008; Prothero and Lubar 2016). The Miolabinae are mostly found in Miocene deposits, but one specific genus, Capricamelus, was found in the Late Pliocene Tecopa Lake Basin south of Death Valley, California. It’s short-legged, mountain goat-like proportions inspired the name “goat camel” (Whistler and Webb 2005). Two genera, Nothokemas and Gentilicamelus, made up the Oligocene-Miocene Nothokemadinae, both showing distinctly downturned snouts (Marriott et al. 2022). The Floridatragulinae (Floridatragulus and Aguascalientia) were llama-like, with “unusually elongated snouts and unreduced dentitions,” from the Miocene (Rincon et al. 2012). Their fossils have been found from Texas and Florida south to Central America. The Miocene Protolabinae (Protolabis, Michenia, and Tanymykter) were once considered ancestral to other camels, but this has since been disputed and the subfamily simply placed within the Camelidae as a “very distinctive group” (Honey et al. 1998). This distinctiveness may have been what caused issues with their placement in Thompson and Wood’s (2018) baraminological analysis (more on that later).

Most camel fossils involve skeletal or dental fossils, but fossil camel tracks are also preserved. Some of the oldest known footprints are from Tezoatlán, Oaxaca, Mexico, with the sediments dated as Upper Eocene-Lower Oligocene. There are a few possible genera that might have made these distinctive tracks (Jiménez-Hidalgo and Guerrero-Arenas 2018).

North American Endemic Subfamilies

Dromedaries in an Egyptian camel market (Jerome Bon, CC BY 2.0)

Bactrian camels and Tien Shan mountains, Kyrgyzstan (Ninara, CC BY 2.0)

The Miocene-Pliocene Camelini are characterized by very large camels (where the Aucheniini only had a few very large llamas) (Harrison 1985). Some of these reached 12+ feet in height. Such large sizes are referenced in the names: Megatylopus, Titanotylopus, Megacamelus. Most of these fossils have been found in western states or the Central Great Plains, though a probable Megatylopus was found at the Gray Fossil Site in Tennessee (DeSantis and Wallace 2008).

While earlier morphological studies (Baskin and Thomas 2016) suggested that the Pliocene-Pleistocene western camel, Camelops, was close to the llamas, paleogenomic data positions it as a sister group to the modern camels, Camelus (Heintzman et al. 2018; Buckley et al. 2019). The Miocene Alforjas has been considered a possible precursor to Camelops (Harrison 1979; Heintzman et al. 2018), but Lynch et al (2020) found Alforjas to be a basal cameline outside both the Camelini and Aucheniini, with Camelops a sister group to the rest of the Camelini. Camelops was one of the cameline lineages that occupied the Arctic for at least a brief period. Camelops hesternus, the western camel, was distributed “from the subtropics of Honduras to the high latitudes of central Alaska and Yukon” (Zazula et al. 2016). Its distribution pattern in northern latitudes suggests that, similar to other animals like ground sloths and giant beavers, its presence there was correlated to periods of interglacial woodlands (Zazula et al. 2011; Zazula et al. 2017).

Old World camels have their origin in a dispersal event of Paracamelus across the Beringian land bridge in the Late Miocene. Which North American genus is ancestral to Paracamelus is uncertain: suggestions include the llama-sized Procamelus, or the oversized Megacamelus, Megatylopus, or Titanotylopus (Van der Made et al. 2002; Caballero et al. 2021). (It is also possible that Procamelus gave rise to the giant camels, which then led to Paracamelus.) Paracamelus included some giant species, whatever the ancestor. Several giant camel finds that are likely Paracamelus are known from Yukon Pleistocene deposits, and giant camel bones from Pliocene deposits on Ellesmere Island, Nunavut, show a very close affinity to those Yukon bones biochemically (Rybczynski et al. 2013; Buckley et al. 2019). Paracamelus shows up in Latest Miocene sites in Asia, Europe, the Middle East, and North Africa, spreading further in the Pliocene (Pickford, et al. 1995; Colombero et al. 2017).

From Paracamelus came Camelus. Today, we have two domesticated species (the dromedary Camelus dromedarius and the Bactrian camel Camelus bactrianus) and one wild species (the wild Bactrian camel Camelus ferus). In Central Asia, Paracamelus appears to have transitioned into the Eurasian Bactrian-like camel Camelus knoblochi in the Middle Pleistocene, with Camelus ferus developing from that species by the Late Pleistocene (Klementiev et al. 2022). Camelus knoblochi appears to have gone extinct during the climatic aridization of the Late Pleistocene, replaced by the Bactrian camel which adapted to the more severe environment (Titov 2008). There are genetic distinctions between the wild and domesticated Bactrian camels, which has suggested to some researchers that further studies might elucidate the relationship of C. knoblochi to the domesticated lineage (Klementiev et al. 2022).

The dromedary is widespread as a domesticated animal in northern Africa, the Middle East, and southwest Asia, but its origins are not well understood due to a lack of fossils from those arid regions. Domestication occurred on the Arabian peninsula, with significant introgression from a now-extinct wild population (Almathen et al. 2016). Fossil Camelus species are known from these regions, but morphological differences suggest that many are not closely related. Pliocene-Pleistocene Camelus sivalensis of India is very similar to ‘advanced’ Paracamelus. The North African giant camel, Camelus thomasi, from the Pleistocene (Mohandesan et al. 2017) had been suggested as a possible distant ancestor of the dromedary, but Martini and Geraads (2018) argued that misidentifications had given the false impression that this had been a widespread species; rather it was limited to Algeria and Morocco. Camelus grattardi was a Pliocene-Pleistocene camel from Ethiopia (Geraads 2014), but its relationship to other fossil Camelus is unclear (Rowan et al. 2018). There are a number of fossil camels from the Middle East currently under study, so we may have a better understanding of the dromedary’s origins in the future. It should be noted that the extant Old World camels all display significant genetic adaptations to living in desert environments (Wu et al. 2014).

Camelinae: Camelini

Dromedary in India (ALMA (Amaury Laporte, CC BY 2.0)

Guanaco and penguins in Argentina (Christian Jiménez, CC BY 2.0)

The llama tribe diverged in North America in the mid-Miocene, with early genera like Pleiolama showing elongate limbs and necks that typify ‘high browsers’ (Webb and Meachen 2004). Aepycamelus, the giant ‘giraffe camel,’ is sometimes placed within this tribe, sometimes as a sister group. Hemiauchenia ranged from the Miocene to Pleistocene across southern and western North America, then crossed into South America in the Late Pliocene when the continents connected (Gasparini et al. 2017), being found in Brazil, Argentina, Chile, and Bolivia. Hemiauchenia is thought to have given rise to Palaeolama (Pliocene-Holocene) in North America, which also crossed into South America (Meachen 2005; Sherer et al. 2007; Rocha-dos-Santos et al. 2017). At least two genera developed within South America: Eulamaops appears in the Pleistocene, while Lama first appears in the Pliocene.

Lama includes four extant species: the (wild) guanaco Lama guanicoe, (wild) vicuña Lama vicugna, (domesticated) llama Lama glama, and (domesticated) alpaca Lama pacos. Some classify the vicuña and alpaca in the genus Vicugna. Genetic research has suggested the guanaco as ancestral to the llama, and the vicuña as ancestral to the alpaca (Kadwell et al. 2001; Marín et al. 2017), though alpacas may have a greater percent of llama admixture (Barreta et al. 2013). There has been a great deal of hybridization between llamas and alpacas, which has caused some genetic confusion (Kadwell et al. 2001). Diaz-Maroto et al. (2021) suggested that alpacas were domesticated through a complicated hybridization history that included a wild guanaco population that no longer exists. Not all domesticated varieties have survived to the present day, either (Mengoni Goñalons and Yacobaccio 2006). Today, the guanaco ranges from the north central Andes to Patagonia, while the vicuña is found only in the high altitude grasslands of the central Andes. Fossil evidence determined that the vicuña was once more widespread, ranging into southern Patagonia during the Pleistocene (Weinstock et al. 2009).

Camelinae: Aucheniini (Lamini)

Vicuña cria, Chile (ALMA (ESO/NAOJ/NRAO)/René Durán, CC BY 2.0)

A Creationist Evaluation of Camelids

For creationists, artiodactyls likely do not form a single baraminic lineage. So many different artiodactyls groups show up in Eocene layers around the world that a more probable explanation is that this is a very early and rapid dispersion event from the Ark involving multiple baraminic lineages. The Camelidae can be treated as a distinct lineage, but we cannot necessarily rule out the possibility that it is part of a multifamilial baraminic lineage. Of course, we also cannot automatically rule out the possibility that the Camelidae is polybaraminic. Wise (2009) suggested the Camelidae could represent an Ark Kind, while Thompson and Wood (2018) suggested that the Camelidae (excluding some ‘basal camelids’) was a holobaramin. One issue with the latter paper is that of the four ‘basal camelids’ those authors noted, only one (Poebrotherium) is truly basal, and it is usually separated into its own subfamily. The others were part of the larger Miocene radiation. I suspect a greater pool of genera and characters from all subfamilies could elucidate further.

For living camelids, hybridization records demonstrate that the tribes Camelini and Aucheniini are in the same baraminic lineage. Llamas and alpacas have a long history of intentional domestic hybridization, with vicuñas and guanacos occasionally being bred into domestic lines (Wheeler et al. 1995). Similarly, dromedaries and Bactrian camels have been hybridized since ancient times to create better pack animals (Dioli 2020), and wild and domestic Bactrian camels interbreed to the detriment of wild camel conservation efforts (Burger 2016). Artificial insemination efforts crossed a dromedary with a guanaco, producing a hybrid (Skidmore et al. 1999).

camels and the flood boundary debate

In regard to the Flood Boundary debate, we can point out a couple of things in regard to camelid evidence. First, despite an extensive Miocene radiation, only the subfamily Camelinae made it to the Pliocene. But within the Camelinae, eight genera cross the Pliocene-Pleistocene boundary: Lama, Hemiauchenia, Palaeolama, Blancocamelus, Camelus, Camelops, Paracamelus, and Titanotylops. Two of those genera are still alive today. This means that creationists who hold to an Upper Cenozoic Flood Boundary must accept a minimum of eight genera of closely-related camelids on the Ark. Of course, those would just be the survivors for which we have post-Flood evidence. Technically, this would mean that each pre-Flood genus should have been on the Ark.

Another issue involving camels relates to the fossils at Ashfall Fossil Beds, the ‘Prairie Pompeii,’ in Nebraska. Numerous large fossil mammals are preserved in “a deposit of light gray vitric ash 2 to 3 meters thick, entirely composed of the walls of microscopic broken bubbles of volcanic rhyolite glass” (Grew 2022). These include the camelids Aepycamelus, Procamelus, and Protolabis. This ash deposit is within the Miocene Ash Hollow Formation of the Ogallala Group, and the ashfall correlates to supervolcanic eruptions originating from Idaho’s Bruneau-Jarbidge caldera (Smith et al. 2018). This is clearly not a Flood deposit. In fact, the mammals at this site show that they had been breathing in the fine, glassy ash for weeks: their bones show patches of rough, frothy pathological growth indicating hypertrophic osteopathy, also known as Bamberger-Marie Disease, that develops from significant lung damage (Grew 2022; UNSM 2023).

A “Recent” Fossil Camel Debate

One last camel fossil to note involves the partial skull of a camel identified as Camelops hesternus, that was found in a lava cave in Tabernacle Crater southwest of Filmore, Utah, in the 1920s. This is a Late Pleistocene lava flow, and the skull was a couple hundred feet back and covered in several feet of dry aeolian deposition, ‘easy to excavate’ by a couple of high school students (Romer 1928). Dr. Alfred Romer was able to determine it was not a recent camel, so not one of the U.S. Army dromedaries released into the southwest in the 1870s. Romer concluded, based on the ‘freshness’ of the skull, which included ligament tissue, that it was very recent, whether hundreds or several thousands of years old. Dr. Oliver Hay (1929) wasn’t happy that this would require revisions to his Pleistocene history, and suggested that the buried skull was protected from decay by the thick dust, possibly for hundreds of thousands of years. (Remind anyone of another soft tissue controversy?)

I can recall first reading about this account in one of William Corliss’s Fortean volumes, as one of those pieces that ‘confounded’ modern science. As it happens, while the camel skull was misplaced for a while, it turned up in the University of Utah Geology Museum and was then re-examined and radiocarbon dated. Nelson and Madsen (1979) noted that the skull dates to latest Pleistocene in age (approx.. 11,000 years before present), and “confirms Romer’s allegation that camels existed in the Great Basin until relatively recent times.” Not, of course, surprising from a creationist perspective, though we’d mark the end of the Pleistocene at a few thousand years B.C.

Alpacas (Phil Long, CC BY 2.0)


Almathen, F., et al. 2016. Ancient and modern DNA reveal dynamics of domestication and cross-continental dispersal of the dromedary. PNAS 113(24): 6707-6712.

Barreta, J., et al. 2013. Analysis of mitochondrial DNA in Bolivian llama, alpaca and vicuna populations: A contribution to the phylogeny of the South American camelids. Animal Genetics 44(2): 158-168.

Baskin, J., and R. Thomas. 2016. A review of Camelops (Mammalia, Artiodactyla, Camelidae), a giant llama from the Middle and Late Pleistocene (Irvingtonian and Rancholabrean) of North America. Historical Biology 28(1-2): 119-126.

Buckley, M., C. Lawless, and N. Rybczynski. 2019. Collagen sequence analysis of fossil camels, Camelops and c.f. Paracamelus, from the Arctic and sub-Arctic of Plio-Pleistocene North America. Journal of Proteomics 194: 218-225.

Burger, P. A. 2016. The history of Old World camelids in the light of molecular genetics. Tropical Animal Health Production 48: 905-913.

Caballero, Ó., et al. 2021. The autopodial skeleton of Paracamelus aguirrei (Morales 1984) (Tylopoda, Mammalia) from the late Miocene site of Venta del Moro (Valencia, Spain). Journal of Iberian Geology 47: 483-500.

Colombero, S., et al. 2017. Paracamelus (Mammalia, Camelidae) remains from the late Messinian of Italy: Insights into the last camels of western Europe. Historical Biology 29(4): 509-518.

Constenius, K. N., and M. R. Dawson. 2008. Blickomylus (Artiodactyla, Camelidae, Stenomylinae) and the age of the Moroni Formation, Central Utah. Journal of Vertebrate Paleontology 28(4): 1228-1231.

DeSantis, L. R. G., and S. C. Wallace. 2008. Neogene forests from the Appalachians of Tennessee, USA: Geochemical evidence from fossil mammal teeth. Palaeogeography, Palaeoclimatology, Palaeoecology 266: 59-68.

Diaz-Maroto, P., et al. 2021. Ancient DNA reveals the lost domestication history of South American camelids in Northern Chile and across the Andes. eLife 10: e63390.

Dioli, M. 2020. Dromedary (Camelus dromedarius) and Bactrian camel (Camelus bactrianus) crossbreeding husbandry practices in Turkey and Kazakhstan: An in-depth review. Pastoralism: Research, Policy and Practice 10(6): 1-20.

Frick, C., and B. E. Taylor. 1968. A generic review of Stenomyline camels. American Museum Novitates (2353): 1-51.

Gasparini, G. M., et al. 2017. The oldest record of Hemiauchenia Gervais and Ameghino (Mammalia, Cetartiodactyla) in South America: Comments about its paleobiogeographic and stratigraphic implications. Geobios 50: 141-153.

Geraads, D. 2014. Camelus grattardi, sp. nov., a new camel from the Shungara Formation, Omo Valley, Ethiopia, and the relationships of African fossil Camelidae (Mammalia). Journal of Vertebrate Paleontology 34(6): 1481-1485.

Grew, P. C. 2022. Ashfall Fossil Beds: A national natural landmark. ProGEO News (2): 4-7.

Halliday, T. J. D., P. Upchurch, and A. Goswami. 2017. Resolving the relationships of Paleocene placental mammals. Biological Reviews 92: 521-550.

Harrison, J. A. 1979. Revision of the Camelinae (Artiodactyla, Tylopoda) and description of the new genus Alforjas. University of Kansas Paleontological Contributions (95): 1-20, 7 plates.

Harrison, J. A. 1985. Giant camels from the Cenozoic of North America. Smithsonian Contributions to Paleobiology (57): 1-29.

Hay, O. P. 1928. An extinct camel from Utah. Science 68(1761): 299-300.

Heintzman, P. D., et al. 2015. Genomic data from extinct North American Camelops revise camel evolutionary history. Molecular Biology and Evolution 32(9): 2433-2440.

Honey, J. G., et al. 1998. Camelidae. in: Evolution of Tertiary Mammals of North America, eds. C. M. Janis, K. M. Scott, and L. L. Jacobs, pp. 439-462. Cambridge: Cambridge University Press.

Janis, C. M., et al. 1998. Artiodactyla. in: Evolution of Tertiary Mammals of North America, eds. C. M. Janis, K. M. Scott, and L. L. Jacobs, pp. 337-357. Cambridge: Cambridge University Press.

Jiménez-Hidalgo, E., and R. Guerrero-Arenas. 2018. The oldest camel footprints from Mexico. Boletín de la Sociedad Geológica Mexicana 70(2): 351-359.

Kadwell, M., et al. 2001. Genetic analysis reveals the wild ancestors of the llama and the alpaca. Proceedings of the Royal Society, London B 268: 2575-2584.

Klementiev, A. M., et al. 2022. First documented Camelus knoblochi Nehring (1901) and fossil Camelus ferus Przewalski (1878) from Late Pleistocene archaeological contexts in Mongolia. Frontiers in Earth Science 10: 861163.

Lynch, S., M. R. Sánchez-Villagra, and A. Balcarcel. 2020. Description of a fossil camelid from the Pleistocene of Argentina, and a cladistic analysis of the Camelinae. Swiss Journal of Palaeontology 139(8): 109-125.

Marín, J. C., et al. 2017. Y-chromosome and mtDNA variation confirms independent domestications and directional hybridization in South American camelids. Animal Genetics 48(5): 591-595.

Marriott, K., D. R. Prothero, and B. L. Beatty. 2022. Systematics of the Nothokemadine camels (Artiodactyla: Camelidae). in: Fossil Record 8, eds. S. G. Lucas et al, 295-302. Bulletin 89. Albuquerque, New Mexico: New Mexico Museum of Natural History & Science.

Martini, P., and D. Geraads. 2018. Camelus thomasi Pomel, 1893 from the Pleistocene type-locality Tighennif (Algeria). Comparisons with modern Camelus. Geodiversitas 40(1): 115-134.

Meachen, J. A. 2005. A new species of Hemiauchenia (Artiodactyla, Camelidae) from the Late Blancan of Florida. Bulletin of the Florida Museum of Natural History 45(4): 435-447.

Mengoni Goñalons, G. L., and H. D. Yacobaccio. 2006. The domestication of South American Camelids. in: Documenting Domestication, eds. M. A. Zeder et al., 228-244. Berkeley, California: University of California Press.

Mohandesan, E., et al. 2017. Combined hybridization capture and shotgun sequencing for ancient DNA analysis of extinct wild and domestic dromedary camel. Molecular Ecology Resources 17: 300-313.

Nelson, M. E., and J. H. Madsen, Jr. 1979. The Hay-Romer camel debate: Fifty years later. Contributions to Geology, University of Wyoming 18(1): 47-50.

Pickford, M., J. Morales, and D. Soria. 1995. Fossil camels from the Upper Miocene of Europe: Implications for biogeography and faunal change. Geobios 28(5): 641-650.

Prothero, D. R., and C. A. Lubar. 2016. Fossil camels from the Late Oligocene Eastlake Local Fauna, Otay Formation, San Diego County, California. in: Fossil Record 5, eds. R. M. Sullivan and S. G. Lucas, 213-221. Bulletin 74. Albuquerque, New Mexico: New Mexico Museum of Natural History & Science.

Rincon, A. F., et al. 2012. New Floridatragulines (Mammalia, Camelidae) from the Early Miocene Las Cascadas Formation, Panama. Journal of Vertebrate Paleontology 32(2): 456-475.

Rocha-dos-Santos, B. C. de A., et al. 2017. The fossil Camelidae (Mammalia: Cetartiodactyla) from the Gruta do Urso cave, northern Brazil. Quaternary International 436A: 181-191.

Romer, A. S. 1928. A “fossil” camel recently living in Utah. Science 68(1749): 19-20.

Rowan, J., et al. 2018. New Pliocene remains of Camelus grattardi (Mammalia, Camelidae) from the Shungara Formation, Lower Omo Valley, Ethiopia, and the evolution of African camels. Historical Biology 31(9): 1123-1134.

Rybczynski, N., et al. 2013. Mid-Pliocene warm-period deposits in the High Arctic yield insight into camel evolution. Nature Communications (1550):1-9.

Scherer, C. S., J. Ferigolo, and A. M. Ribeiro. 2007. Contribution to the knowledge of Hemiauchenia paradoxa (Artiodactyla, Camelidae) from the Pleistocene of Southern Brazil. Revista Brasileira de Paleontologia 10(1): 35-52.

Skidmore, J. A., et al. 1999. Hybridizing Old and New World camelids: Camelus dromedarius x Lama guanicoe. Proceedings of the Royal Society, London B 266: 649-656.

Smith, J. J., et al. 2018. First U-Pb zircon ages for late Miocene Ashfall Konservat-Lagerstätte and Grove Lake ashes from eastern Great Plains, USA. PLoS ONE 13(11): e0207103.

Thompson, C., and T. C. Wood. 2018. A survey of Cenozoic mammal baramins. in: Proceedings of the Eighth International Conference on Creationism, ed. John H. Whitmore, 217-221. Pittsburgh, Pennsylvania: Creation Science Fellowship.

Titov, V. V. 2008. Habitat conditions for Camelus knoblochi and factors in its extinction. Quaternary International 179: 120-125. University of Nebraska State Museum. 2023. Ashfall Fossil Beds.

Van der Made, J., et al. 2002. The first camel from the Upper Miocene of Turkey and the dispersal of the camels into the Old World. Comptes Rendus Palevol 1: 117-122.

Webb, S. D., and J. Meachen. 2004. On the origin of the lamine Camelidae including a new genus from the Late Miocene of the High Plains. Bulletin of Carnegie Museum of Natural History (36): 349-362.

Weinstock, J., et al. 2009. The Late Pleistocene distribution of vicuñas (Vicugna vicugna) and the “extinction” of the gracile llama (“Lama gracilis”): New molecular data. Quaternary Science Reviews 28: 1369-1373.

Wheeler, J. C., A. J. F. Russel, and H. Redden. 1995. Llamas and alpacas: Pre-conquest breeds and post-conquest hybrids. Journal of Archaeological Science 22: 833-840.

Whistler, D. P., and S. D. Webb. 2005. New goatlike camelid from the Late Pliocene of Tecopa Lake Basin, California. Contributions in Science (Natural History Museum of Los Angeles County) (503): 1-40.

Wise, K. P. 2009. Mammal kinds: How many were on the Ark? in: Genesis Kinds: Creationism and the Origin of Species, eds. T. C. Wood and P. A. Garner, 129-161. Center for Origins Research Issues in Creation, No. 5. Eugene, Oregon: Wipf and Stock.

Wu, H., et al. 2014. Camelid genomes reveal evolution and adaptation to desert environments. Nature Communications (5188): 1-9.

Zazula, G. D., et al. 2011. Last interglacial western camel (Camelops hesternus) from eastern Beringia. Quaternary Science Reviews 30: 2355-2360.

Zazula, G. D., et al. 2016. Osteological assessment of Pleistocene Camelops hesternus (Camelide: Camelinae: Camelini) from Alaska and Yukon. American Museum Novitates (3866): 1-45.

Zazula, G. D., et al. 2017. A case of early Wisconsinan ‘over-chill’: New radiocarbon evidence for early extirpation of western camel (Camelops hesternus) in eastern Beringia. Quaternary Science Reviews 171: 48-57.

Llama (Phil Whitehouse, CC BY 2.0)