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Dental wear patterns were recorded on 458 deciduous molar teeth, of 142 subadults from late medieval (AD 1086–1539) England, to explore the relationship between dental wear and burial status of children. A new ordinal method for scoring dental wear stages on the deciduous molar teeth was devised. It was postulated that if a discernible relationship between dental wear stage and burial location could be seen then this could reflect a difference in diet between those receiving higher or lower status burial. The dental wear stages recorded were statistically similar for the dentitions of subadults from different cemeteries, as well as from different burial locations, indicating a comparable diet for the children studied. Am J Phys Anthropol, 2013. © 2013 Wiley Periodicals, Inc. 相似文献
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中亚热带主要树种凋落叶在杉木人工林中分解及氮磷释放过程 总被引:2,自引:0,他引:2
采用分解网袋法研究了马尾松(Pinus massoniana)、桤木(Alnus cremastogyne)、木荷(Schima superba)、青冈(Cycloblanopsis glauca)等树种凋落叶在21年生杉木人工林内的分解速率和养分释放过程。经过13个月的分解实验,4种供试凋落叶以青冈分解最快,质量失重率为33.5%,其次为桤木和木荷,马尾松分解最慢,其质量失重率仅为29.9%。4种凋落叶分解50%和95%所需要的时间分别为21~26个月和94~112个月。在凋落叶分解过程中,除桤木凋落叶中氮含量下降外,其他3种凋落叶的氮含量均增加,但凋落叶的C/N均降低;在凋落叶分解的前3个月,凋落物中磷含量快速下降,此后变化很小,C/P呈增加趋势。在凋落叶分解过程中,马尾松凋落叶对氮素表现为固持作用,而其他3种凋落叶对氮素表现为净释放,4种凋落叶的磷素均表现为净释放。4种供试材料中桤木较适合与杉木混交种植。 相似文献
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Cory J. D. Matthews Fred J. Longstaffe Steven H. Ferguson 《Ecology and evolution》2016,6(14):4643-4653
Spatial variation in marine oxygen isotope ratios (δ18O) resulting from differential evaporation rates and precipitation inputs is potentially useful for characterizing marine mammal distributions and tracking movements across δ18O gradients. Dentine hydroxyapatite contains carbonate and phosphate that precipitate in oxygen isotopic equilibrium with body water, which in odontocetes closely tracks the isotopic composition of ambient water. To test whether dentine oxygen isotope composition reliably records that of ambient water and can therefore serve as a proxy for odontocete distribution and movement patterns, we measured δ18O values of dentine structural carbonate (δ18OSC) and phosphate (δ18OP) of seven odontocete species (n = 55 individuals) from regional marine water bodies spanning a surface water δ18O range of several per mil. Mean dentine δ18OSC (range +21.2 to +25.5‰ VSMOW) and δ18OP (+16.7 to +20.3‰) values were strongly correlated with marine surface water δ18O values, with lower dentine δ18OSC and δ18OP values in high‐latitude regions (Arctic and Eastern North Pacific) and higher values in the Gulf of California, Gulf of Mexico, and Mediterranean Sea. Correlations between dentine δ18OSC and δ18OP values with marine surface water δ18O values indicate that sequential δ18O measurements along dentine, which grows incrementally and archives intra‐ and interannual isotopic composition over the lifetime of the animal, would be useful for characterizing residency within and movements among water bodies with strong δ18O gradients, particularly between polar and lower latitudes, or between oceans and marginal basins. 相似文献
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Christopher W. Schmidt Ashley Remy Rebecca Van Sessen John Willman Kristin Krueger Rachel Scott Patrick Mahoney Jeremy Beach Jaqueline McKinley Ruggero D'Anastasio Laura Chiu Michele Buzon J. Rocco De Gregory Susan Sheridan Jacqueline Eng James Watson Haagen Klaus Pedro Da-Gloria Jeremy Wilson Abigail Stone Paul Sereno Jessica Droke Rose Perash Christopher Stojanowski Nicholas Herrmann 《American journal of physical anthropology》2019,169(2):207-226
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Sciulli PW 《American journal of physical anthropology》2001,116(2):140-153
Deciduous tooth size in Native Americans of the Ohio Valley area is fairly stable from the terminal Late Archaic (3200 BP) through the Late Prehistoric (350 BP) periods. Some fluctuation in average size did occur during this time. These fluctuations most likely reflect random changes due to gene drift. However, no difference in the pattern of interactions among the sizes of teeth (covariance structures) can be demonstrated during this period. Principal components analysis of the buccolingual and mesiodistal dimensions in the total sample indicate that the major axis of deciduous tooth size in the Ohio Valley population shows an allometric relationship, with the dimensions of the anterior teeth increasing (or decreasing) as the 1.33 power of the dimension of m1(1) and as the 2.0 power of the dimension of m2(2). Comparison of the Ohio Valley samples with other samples from the Eastern Woodlands suggests that geography may have played a minor role in structuring deciduous tooth size variation. For the most part, however, widely separated Eastern Woodlands populations appear to have been evolving independently with respect to deciduous tooth size. 相似文献
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PATRICIA W. FREEMAN 《Biological journal of the Linnean Society. Linnean Society of London》1992,45(2):97-115
Upper canines in microchiropteran bats show a variety of cross-sectional shapes. A consistent feature of all species studied here is that the tooth is edged and not simply round or oval. Prominent sharp edges are positioned in several directions but particularly antero-medially toward the incisors and posteriorly toward the premolars. These edges appear to direct the cracks made in food items to the incisors or to the premolars. A continuous cutting edge is apparent in the occlusal view of the palate running from tip of canine to the ectoloph of the molars. Size and shape analysis indicates that larger bats have slender, rather than stouter, canines for their height, a condition that may be attributable to the nature of the prey. Most bats take prey that have little hard substance imbedded within. The compromises in tooth shape may vary between that of a terrestrial predator with short, conical canines for processing endoskeletal prey to that of a small flying predator with long, slender, edged canines for capturing and processing exoskeletal prey. Unicuspid teeth and how they might function in food break-up have been overlooked to the literature; such a study could lead to an understanding of how more complex teeth function. 相似文献
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Morse DE Holm-Pedersen P Holm-Pedersen J Katz RV Viitanen M von Strauss E Winblad B 《Gerodontology》2002,19(2):73-79
Objectives: The Kungsholmen Elders Oral Health Study (KEOHS) evaluated the oral health status of generally healthy, community‐dwelling persons over the age of 80 living in Kungsholmen, Sweden. This paper explored possible clinical risk indicators of coronal and root caries among the KEOHS subjects. Design: In this cross‐sectional study, dentate KEOHS subjects received a caries assessment using defined visual, tactile criteria. Setting: Examinations were carried out in two local clinics by standardized examiners. Subjects: One hundred twenty‐nine dentate persons were examined. Main Outcome Measures: The examination identified decayed and filled surfaces, prosthetic crowns, and missing teeth. Results: More root than coronal surfaces had untreated decay, and secondary root caries contributed the greatest number of decayed surfaces. Ninety percent of the examined dentate subjects had at least one prosthetic crown. Root surfaces exposed to crown margins were more likely to have caries than root surfaces not so exposed, particularly among women. The presence of untreated coronal caries (yes/no) was positively associated with having untreated root caries and an intermediate number (14–20) of teeth, but inversely associated with having 4+ prosthetic crowns. Active root caries (yes/no) was positively associated with having untreated coronal caries, 14–20 teeth, and 4+ prosthetic crowns. Nearly 20% of identified root lesions were present at or below the gingival margin, and most (88%) were secondary caries associated with crown margins (65%) or other restorations (23%). Conclusions: Our findings suggest that some dental characteristics, including the presence of prosthetic crowns, are risk indicators for the presence of untreated coronal and root caries. 相似文献