Dietary Ecology of Pleistocene Quaternary Camels

Dietary ecology of Pleistocene camelids: Influences of climate, environment, and sympatric taxa

Authors:

Yann et al

Abstract:

Wild members of Camelidae live in some of the most arid environments, including North Africa, Arabia, the Gobi Desert of China and Mongolia and high elevation environments in the Andes Mountains. A better understanding of the paleoecology of the three most abundant Pleistocene camelids (Camelops, Hemiauchenia, and Palaeolama) may clarify modern adaptations to arid environments. Mammalian tooth enamel δ13C values were used to compare diets of co-occurring species in California, Texas, and Florida and δ18O values were used to investigate climate. Carbon isotope analysis suggests Camelops was likely an opportunistic browser that consumed both C3 and C4 browse/CAM plants, potentially consuming C4 browse (e.g., saltbush). Hemiauchenia had an opportunistic and highly generalized diet, while Palaeolama was a specialized forest browser. Stable oxygen isotopes and aridity index values suggest that Ingleside was warmer than McKittrick Brea, but there are no significant differences in aridity between the two sites. Co-occurrence data from the Paleobiology Database suggest that Palaeolama was restricted to forested environments as it occurred with two browsers, Tapirus and Odocoileus, at 90.5% of all sites. Camelops and Hemiauchenia both co-occurred with a broader range of taxa, further suggesting these camelids lived in diverse habitats. The generalized diet of Hemiauchenia, the likely ancestor of modern South American camelids, allowed for the adaptations of extant Lama and Vicugna to survive in the arid environments of the Andes Mountains. Collectively, these data clarify the dietary ecology of extinct camelids and provide insight into the potential importance of generalist diets for increased resilience to changing environments and/or climates.

Camels Originally Domesticated in Southern Arabia

Burger and her team succeeded in answering this question. The group of researchers analysed up to 7,000-year-old DNA from bones of wild and early-domesticated dromedaries and compared the samples with the genetic profiles of modern dromedary populations from around the world. For the first time, it was possible to identify the Southeast Arabian Peninsula as the region of first domestication. "Our results appear to confirm that the first domestication of wild dromedaries occurred on the southeast coast. This was followed by repeated breeding of wild dromedaries with the early-domesticated populations," Burger explains. The wild ancestor of today's dromedary had a geographically limited range and went extinct around 2,000 years after the first domestication.

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15 Sites are Considered Undisputed Examples of Clovis Era Human Predation of Megafauna

Revisiting Paleoindian Exploitation of Extinct North American Mammals

Authors:

Grayson et al

Abstract:

In 2002, we assessed all sites known to us that had been suggested to provide evidence for the association of Clovis-era archaeological material with the remains of extinct Pleistocene mammals in North America. We concluded that, of the 76 sites we assessed, 14 provided compelling evidence for human involvement in the death and/or dismemberment of such mammals. Of these sites, 12 involved mammoth (Mammuthus), the remaining two mastodon (Mammut). Here, we update that assessment. We examine Clovis-era, and earlier, sites reported since 2002, as well as sites examined previously but for which additional information has become available. Our assessment leads us to exclude Hebior (Wisconsin) from the list of accepted sites, and to add El Fin del Mundo (Sonora) and Wally’s Beach (Alberta). There are now 15 sites on our list, providing what we find to be compelling evidence for human involvement in the death and/or dismemberment of five genera of now-extinct late Pleistocene mammals: Equus, Camelops, Cuvieronius, Mammut, and Mammuthus. As in 2002, however, we note this is a small fraction of the 37 genera that disappeared at the end of the Pleistocene, and for this and other reasons we remain highly skeptical that human overkill was responsible for their extinction.