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\"Today, we know that a mammoth is an extinct type of elephant that was covered with long fur and lived in the north country during the ice ages. But how do you figure out what a mammoth is if you have no concept of extinction, ice ages, or fossils? Long after the last mammoth died and was no longer part of the human diet, it still played a role in human life. Cultures around the world interpreted the remains of mammoths through the lens of their own worldview and mythology. When the ancient Greeks saw deposits of giant fossils, they knew they had discovered the battle fields where the gods had vanquished the Titans. When the Chinese discovered buried ivory, they knew they had found dragons' teeth. But as the Age of Reason dawned, monsters and giants gave way to the scientific method. Yet the mystery of these mighty bones remained. How did Enlightenment thinkers overcome centuries of myth and misunderstanding to reconstruct an unknown animal? The journey to unravel that puzzle begins in the 1690s with the arrival of new type of ivory on the European market bearing the exotic name \"mammoth.\" It ends during the Napoleonic Wars with the first recovery of a frozen mammoth. The path to figuring out the mammoth was traveled by merchants, diplomats, missionaries, cranky doctors, collectors of natural wonders, Swedish POWs, Peter the Great, Ben Franklin, the inventor of hot chocolate, and even one pirate. McKay brings together dozens of original documents and illustrations, some ignored for centuries, to show how this odd assortment of characters solved the mystery of the mammoth and, in doing so, created the science of paleontology.\"-- Dust jacket.

A new species of mastodon from the Pleistocene of western North America, Mammut pacificus sp. nov. is herein recognized, with specimens identified throughout California and from two localities in southern Idaho. This new taxon differs from the contemporaneous M. americanum in having narrower teeth, most prominently in M3/m3, as well as six sacral vertebrae, femur with a proportionally greater mid-shaft diameter, and no mandibular tusks at any growth stage. All known Pleistocene Mammut remains from California are consistent with our diagnosis of M. pacificus , which indicates that M. americanum was not present in California.

Elephantids are the world’s most iconic megafaunal family, yet there is no comprehensive genomic assessment of their relationships. We report a total of 14 genomes, including 2 from the American mastodon, which is an extinct elephantid relative, and 12 spanning all three extant and three extinct elephantid species including an ∼120,000-y-old straight-tusked elephant, a Columbian mammoth, and woolly mammoths. Earlier genetic studies modeled elephantid evolution via simple bifurcating trees, but here we show that interspecies hybridization has been a recurrent feature of elephantid evolution. We found that the genetic makeup of the straight-tusked elephant, previously placed as a sister group to African forest elephants based on lower coverage data, in fact comprises three major components. Most of the straight-tusked elephant’s ancestry derives from a lineage related to the ancestor of African elephants while its remaining ancestry consists of a large contribution from a lineage related to forest elephants and another related to mammoths. Columbian and woolly mammoths also showed evidence of interbreeding, likely following a latitudinal cline across North America. While hybridization events have shaped elephantid history in profound ways, isolation also appears to have played an important role. Our data reveal nearly complete isolation between the ancestors of the African forest and savanna elephants for ∼500,000 y, providing compelling justification for the conservation of forest and savanna elephants as separate species.

The peopling of the Americas is a topic of ongoing scientific interest and rigorous debate1,2. Holen et al.3 add to these discussions with their recent report of a 130,000-year-old archaeological site in southern California, USA: the Cerutti Mastodon (CM) site, which includes the fragmentary remains of a single mastodon (Mammut americanum), spatially associated stone cobbles, and associated lithic debris that they claim indicates prehistoric hominin activity.

Significance New radiocarbon ( ¹⁴C) dates on American mastodon ( Mammut americanum ) fossils in Alaska and Yukon suggest this species suffered local extirpation before terminal Pleistocene climate changes or human colonization. Mastodons occupied high latitudes during the Last Interglacial (∼125,000–75,000 y ago) when forests were established. Ecological changes during the Wisconsinan glaciation (∼75,000 y ago) led to habitat loss and population collapse. Thereafter, mastodons were limited to areas south of the continental ice sheets, where they ultimately died out ∼10,000 ¹⁴C years B.P. Extirpation of mastodons and some other megafaunal species in high latitudes was thus independent of their later extinction south of the ice. Rigorous pretreatment was crucial to removing contamination from fossils that originally yielded erroneously “young” ¹⁴C dates. Existing radiocarbon ( ¹⁴C) dates on American mastodon ( Mammut americanum ) fossils from eastern Beringia (Alaska and Yukon) have been interpreted as evidence they inhabited the Arctic and Subarctic during Pleistocene full-glacial times (∼18,000 ¹⁴C years B.P.). However, this chronology is inconsistent with inferred habitat preferences of mastodons and correlative paleoecological evidence. To establish a last appearance date (LAD) for M. americanum regionally, we obtained 53 new ¹⁴C dates on 36 fossils, including specimens with previously published dates. Using collagen ultrafiltration and single amino acid (hydroxyproline) methods, these specimens consistently date to beyond or near the ∼50,000 y B.P. limit of ¹⁴C dating. Some erroneously “young” ¹⁴C dates are due to contamination by exogenous carbon from natural sources and conservation treatments used in museums. We suggest mastodons inhabited the high latitudes only during warm intervals, particularly the Last Interglacial [Marine Isotope Stage (MIS) 5] when boreal forests existed regionally. Our ¹⁴C dataset suggests that mastodons were extirpated from eastern Beringia during the MIS 4 glacial interval (∼75,000 y ago), following the ecological shift from boreal forest to steppe tundra. Mastodons thereafter became restricted to areas south of the continental ice sheets, where they suffered complete extinction ∼10,000 ¹⁴C years B.P. Mastodons were already absent from eastern Beringia several tens of millennia before the first humans crossed the Bering Isthmus or the onset of climate changes during the terminal Pleistocene. Local extirpations of mastodons and other megafaunal populations in eastern Beringia were asynchrononous and independent of their final extinction south of the continental ice sheets.

Fossilized bones from extinct taxa harbor the potential for obtaining protein or DNA sequences that could reveal evolutionary links to extant species. We used mass spectrometry to obtain protein sequences from bones of a 160,000- to 600,000-year-old extinct mastodon (Mammut americanum) and a 68-million-year-old dinosaur (Tyrannosaurus rex). The presence of T. rex sequences indicates that their peptide bonds were remarkably stable. Mass spectrometry can thus be used to determine unique sequences from ancient organisms from peptide fragmentation patterns, a valuable tool to study the evolution and adaptation of ancient taxa from which genomic sequences are unlikely to be obtained.

Mammut pacificus is a recently described species of mastodon from the Pleistocene of California and Idaho. We report the easternmost occurrence of this taxon based upon the palate with right and left M3 of an adult male from the Irvingtonian of eastern Montana. The undamaged right M3 exhibits the extreme narrowness that characterizes M . pacificus rather than M . americanum . The Montana specimen dates to an interglacial interval between pre-Illinoian and Illinoian glaciation, perhaps indicating that M . pacificus was extirpated in the region due to habitat shifts associated with glacial encroachment.

Proboscidean limb bones discovered in Yukon during the 1960s and 1970s exhibit fracture patterns, notches, and bone flakes that are characteristic of percussion. Because of the unique properties of thick cortical proboscidean bone (probably woolly mammoth Mammuthus primigenius or less likely American mastodon Mammut americanum), some researchers hypothesized that these fracture patterns represent intentional hammerstone modification by humans for marrow extraction and bone tool production. As such, these fracture patterns represent evidence of early human dispersal into Eastern Beringia. Radiocarbon dating in the late 1980s indicated that the bone breakage occurred between about 25 000 and 40 000 radiocarbon years before present (14C yr BP). We report 11 new radiocarbon ages using ultra-filtration methods on a different sample of similarly fractured and flaked bones from Yukon. Only two of the radiocarbon ages fall within the expected range of 25 000 to 40 000 14C yr BP. Six other ages are non-finite, with five being more than 49 100 14C yr BP. Three finite ages range between 46 500 and 50 500 14C yr BP with large standard deviations, and these ages may also be non-finite. Two testable hypotheses to explain the observed breakage patterns were developed, the first being that humans broke the bones and the second that some presently unknown geological process broke the bones. Further research is needed to test these two hypotheses. Des ossements de membres de proboscidiens découverts au Yukon dans les années 1960 et 1970 présentent des structures de fractures, des encoches et des traces d'enlèvements d'éclats caractéristiques de la percussion. En raison des propriétés uniques de l'os cortical proboscidien (provenant probablement d'un mammouth laineux Mammuthus primigenius ou, ce qui est moins probable, d'un mastodonte américain Mammut americanum), certains chercheurs ont avancé une hypothèse selon laquelle ces structures représentent des modifications intentionnelles faites au marteau en pierre par des humains, à des fins d'extraction de la moelle et de production d'outils en os. En tant que telles, ces structures de fractures témoignent de la présence ancienne d'humains dans l'est de la Béringie. Vers la fin des années 1980, la datation au radiocarbone a permis de déterminer que les fractures auraient été faites il y a environ 25 000 à 40 000 années radiocarbones avant le présent (14C ans BP). Nous faisons état de 11 nouveaux âges au radiocarbone établis au moyen de méthodes d'ultrafiltration sur un échantillon différent d'os provenant également du Yukon et présentant de semblables fractures et traces d'enlèvements d'éclats. Seulement deux des âges au radiocarbone font partie de la gamme attendue variant entre 25 000 et 40 000 14C ans BP. Six autres âges sont non finis, dont cinq ayant plus de 49 100 14C ans BP. Trois âges finis varient entre 46 500 et 50 500 14C ans BP et ont d'importants écarts-types, et ces âges pourraient également être non finis. Deux hypothèses testables ont été émises afin d'expliquer les structures de fractures observées, la première étant que les fractures ont été causées par des humains et la seconde étant que les fractures sont le résultat d'un processus géologique inconnu à ce jour. Des recherches plus approfondies s'imposent afin de mettre ces deux hypothèses à l'épreuve.

Characteristics of social structure, mating strategies, and parental investment can be inferred for mammalian species based on degree of sexual dimorphism, especially when males are substantially larger than females. American mastodons ( Mammut americanum ) and extant African elephants ( Loxodonta africana , Loxodonta cyclotis ) both exhibit marked dimorphism in tusk size. To evaluate the hypothesis that this dimorphism might be indicative of similar, and possibly conserved, behavioral patterns in each lineage, we undertook a detailed evaluation of the pattern of tusk growth in these two genera. Separate discriminant function analyses (DFA) of 21 adult mastodon tusks of inferred sex and 48 adult elephant tusks of known sex show that patterns of ontogenetic change in tusk circumference, regardless of genus, effectively discriminate between sexes. Canonical variates analysis (CVA) of tusks from male and female mastodons and male and female elephants shows that male tusks in both genera are larger than female tusks across all measurements, especially for maximum tusk circumference and pulp cavity depth. CVA’s emphasis of inter-group differences in tusk morphology also shows that mastodon tusks are more robust than elephant tusks. Overall, this study illustrates that there is a characteristic male and a characteristic female tusk form shared by elephants and mastodons. This shows that elephants and mastodons display a shared syndrome of traits beyond sex-linked differences in tusk size, supporting the hypothesis that mastodons exhibited behaviors similar to those we observe today in African elephants.

Documenting sexual dimorphism for structures that exhibit indeterminate growth can be more difficult than for structures exhibiting determinate growth. Most proboscidean tusks are ever-growing structures that change size and shape throughout life. Sexual dimorphism is pronounced in tusks of mature individuals, but the external form of tusks offers no clear evidence of maturation, and it is difficult to distinguish a young male's tusk from that of an older female. Thus, with previous approaches, knowledge of age was often required to assess sex from tusk measurements. This study examines sexual dimorphism of American mastodon (Mammut americanum) tusks through principal components analysis to determine which aspects of tusk form contribute most strongly to the variance among measurements and to explore the relationship between tusk form and individual age and sex. Twenty-one mastodon tusks from the Great Lakes region were evaluated in two analyses, the first focusing on geometrically distinct aspects of tusk form and the second adding measurements that reflect ontogenetic changes in a single aspect of morphology (circumference). Both analyses separated mastodons by sex (PC-I) and sorted them by age (PC-II). The distribution of tusks on the PC-II versus PC-I plane provides better discrimination of sex than univariate or bivariate methods because tusks of similar size and opposite sex appear near opposite ends of an age spectrum. The second analysis enhances sorting by age, thereby clarifying assessment of sex. This work contributes to studies of mastodon paleobiology by presenting a reliable method for assessing the sex of an individual from tusk measurements without requiring independent knowledge of age.