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Rountrey A.N.,University of Michigan | Fisher D.C.,University of Michigan | Tikhonov A.N.,Russian Academy of Sciences | Kosintsev P.A.,Russian Academy of Sciences | And 3 more authors.
Quaternary International | Year: 2012

The Yamal mammoth calf " Lyuba" and the Oimyakon mammoth calf are two recently collected, mummified woolly mammoth calves both dating to around 41 ka. They offer opportunities to study the earliest parts of mammoth life history through microstructural and compositional analyses of tooth dentin. Understanding mammoth paleobiology is critical for assessing how populations might have responded to ecological changes in the late Pleistocene, and such assessment will aid in determining the likely cause(s) of extinction.The state of tooth eruption and wear in Lyuba suggests that she died quite young. Prominent constrictions in the roots of the dP2s and dP 3 correspond to neonatal lines in the dentin of each tooth, marking the time of birth. The neonatal line in dP 2 allowed us to estimate the duration of prenatal development, determine Lyuba's age at death, and place birth in the context of variation in isotopic and elemental composition of the dentin.Growth increments and seasonal variation in δ 15N indicate that Lyuba's dP 2 records over a year of prenatal development, suggesting duration of gestation was similar to that observed in elephants. Death occurred at about 30-35 days, and birth appears to have occurred in spring.The Oimyakon specimen represents an individual older (biologically) than Lyuba. The dP2s have been lost, and most plates of the dP3s are in wear. An unerupted permanent tusk is present, but no deciduous tusk is present in the single recovered premaxilla. The tusk exhibits a circumferential ridge at mid-length that represents the surface expression of a prominent growth line in the dentin. Based on its prominence and elevated dentin Zn/Ca in its vicinity, this is interpreted as a neonatal line. Its occurrence in the tusk is of interest because this implies initiation of permanent tusk mineralization months before birth- yet permanent tusks are not present in Lyuba. Differences in timing of tusk development may result from individual, population, or sexual variation.Growth increments in the tusk indicate death at an age of about 7 months with both δ 15N and δ 13C generally declining postnatally. The increment-based age at death is less than an estimate based on the state of cheek tooth eruption and wear (using extant elephants as references), implying that ages based on comparisons to elephants may be inaccurate. Counts of dentin growth increments combined with identification of seasonally varying aspects of dentin composition could be used to calibrate the cheek tooth aging system for Mammuthus primigenius. © 2011 Elsevier Ltd and INQUA. Source


Mashchenko E.N.,Russian Academy of Sciences | Protopopov A.V.,Academy of science of the Republic of Sakha Yakutia | Plotnikov V.V.,Institute of Applied Ecology of the North | Pavlov I.S.,Yroslavskii Yakutian United Museum of History and Culture of Peoples of the North
Biology Bulletin | Year: 2013

The exterior, skeletal morphology, and teeth of a 4- to 5-month-old woolly mammoth calf, Mammuthus primigenius Proboscidea, Elephantidae from the Khroma River (Yakutia, Russia) are described. This is the third and best preserved frozen carcass of the mammoth calves from Yakutia. The calf is male (penis available). The individual age as determined by the degree of wearing of DP2 and the beginning of wear of DP3 corresponds to the stage of transition to combined feeding (milk and vegetal forage). At the same time, formation of the cranial sutures (sutura sagittalis, fronto-temporalis, squamo-temporalis, and the suture between os occipitale superior and os occipitale inferior) testifies to an older juvenile stage. The proximal and distal epiphyses of the humerus and the distal epiphysis of the femur are represented by paired centers of ossification. A comparison of the dimensions of the head, body, and legs with the corresponding parameters of other M. primigenius calves of the same age shows the individual variability (10-15%) of these features. Although of medium size characteristic of M. primigenius calves, the described individual lacks subcutaneous fat deposits in the withers and subdermal areas of the body flanks. Death was caused by a rupture of the body and vertebral column at the level of the pectoral vertebrae 11-12. The deformation of the legs and longitudinal stretching of the soft tissues of the body caused no bone fractures (except for three ribs in the zone of the rupture). The long bones are not dislocated either in the shoulder and pelvic girdles or relative to each other. Possible causes and the timing of the death of the mammoth calves preserved in the permafrost are discussed. © 2013 Pleiades Publishing, Inc. Source


Gavril'eva L.D.,Institute of Applied Ecology of the North
Contemporary Problems of Ecology | Year: 2011

In this paper, we characterize communities of the class Artemisietea jacuticae Gogoleva et al. 1987 in alas meadows of the Lena-Amga interfluve in Central Yakutia. Comparison of vegetation syntaxa identified during the study with previously published data shows that some communities identified in the alases have previously been found only in human settlements. © 2011 Pleiades Publishing, Ltd. Source


Boeskorov G.G.,Russian Academy of Sciences | Lazarev P.A.,Institute of Applied Ecology of the North | Sher A.V.,RAS A.N. Severtsov Institute of Ecology and Evolution | Davydov S.P.,Russian Academy of Sciences | And 6 more authors.
Quaternary Science Reviews | Year: 2011

A nearly complete frozen mummy of a woolly rhinoceros (Coelodonta antiquitatis Blum., 1799) was discovered in a gold mine on the lower reaches of the Kolyma River, north-eastern Siberia. This is the first find of the whole body of woolly rhino in permafrost. A large part of the mummified body was preserved, including the left part of the body, covered by skin, including skin of the head and ear, fore and hind legs. The skull with 2 horns and the lower jaw were also preserved. Most of the internal organs were lost, except the intestines, stomach, and their contents. A rib fragment from this individual was dated by AMS-radiocarbon method to 39,140 ± 390 years BP (OxA-18755). Spore and pollen analyses of the stomach contents indicate that grasses and sagebrushes formed the main part of the diet of C. antiquitatis in this region of Arctic Siberia. © 2011 Elsevier Ltd. Source


Ivanova T.I.,Russian Academy of Sciences | Kuz'mina N.P.,Russian Academy of Sciences | Savvinov D.D.,Institute of Applied Ecology of the North
Eurasian Soil Science | Year: 2013

The specific features of the microbial population in the soils of alases (thermokarst depressions) of Central Yakutia were revealed: a high number of microorganisms of all the groups (1. 1 × 103-3. 9 × 108 cell/g), which is compatible with the microbial density in the steppe soils of Transbaikalia; a particular distribution of the microorganisms along their profiles without decreasing of their number with the depth; and insignificant fluctuations of their population density in some soil horizons. The enrichment of these soils with microorganisms depends on the hydrothermal conditions. The microbial number gradually increases from the elevated peripheral parts of the alases to their centers and drastically decreases towards the lower lakeside areas of the alases. At the same time, the composition of the microorganisms changes, and nitrogen-fixing bacteria appear. © 2013 Pleiades Publishing, Ltd. Source

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