Department of Earth and Environmental Science, Vanderbilt University, Nashville, Tennessee, United States of America.
Department of Anthropology, Vanderbilt University, Nashville, Tennessee, United States of America.
PLoS One. 2018 Aug 22;13(8):e0201962. doi: 10.1371/journal.pone.0201962. eCollection 2018.
Dental mesowear analysis can classify the diets of extant herbivores into general categories such as grazers, mixed-feeders, and browsers by using the gross wear patterns found on individual teeth. This wear presumably results from both abrasion (food-on-tooth wear) and attrition (tooth-on-tooth wear) of individual teeth. Mesowear analyses on extinct ungulates have helped generate hypotheses regarding the dietary ecology of mammals across space and time, and recent developments have expanded the use of dental mesowear analysis to herbivorous marsupial taxa including kangaroos, wombats, possums, koalas, and relatives. However, the diet of some of the most ubiquitous kangaroos (e.g., Macropus giganteus) along with numerous other species cannot be successfully classified by dental mesowear analysis. Further, it is not well understood whether climate variables (including precipitation, relative humidity, and temperature) are correlated with dental mesowear variables including various measures of shape and relief. Here, we examine the relationship between dental mesowear variables (including traditional methods scoring the sharpest cusp and a new potential assessment of multiple cusps) and climate variables in the grazers/mixed feeders Macropus giganteus and Macropus fuliginosus, and the obligate browser Phascolarctos cinereus. We find that dental mesowear of mandibular teeth is capable of differentiating the dietary habits of koalas and the kangaroo species. Furthermore, both Macropus giganteus and Phascolarctos cinereus exhibit mesowear correlated with mean minimum temperature, while Macropus fuliginosus dental mesowear is unaffected by temperature, despite significant differences in mean minimum and mean maximum temperature across their distribution (and in the specimens examined here). Contrary to expectations that individuals from drier regions would have blunter and lower relief teeth, dental mesowear is unrelated to proxies of relative aridity-including mean annual precipitation and relative humidity. Collectively, dental mesowear in these marsupials is related to feeding behavior with increased wear in cooler regions (in Macropus giganteus and Phascolarctos cinereus) potentially related to more or different food resources consumed.
牙齿微观磨损分析可以通过观察个体牙齿上的总磨损模式，将现存草食动物的饮食分为一般类别，如食草动物、杂食动物和食叶动物。这种磨损可能是由个体牙齿的磨损（食物与牙齿之间的磨损）和磨耗（牙齿与牙齿之间的磨损）共同造成的。对已灭绝的有蹄类动物的微观磨损分析有助于生成关于哺乳动物在空间和时间上的饮食生态学假说，最近的发展扩大了牙齿微观磨损分析在食草有袋类动物分类群中的应用，包括袋鼠、袋熊、负鼠、考拉和它们的亲属。然而，一些最常见的袋鼠（如巨型袋鼠）以及许多其他物种的饮食无法通过牙齿微观磨损分析进行成功分类。此外，气候变量（包括降水、相对湿度和温度）与牙齿微观磨损变量（包括各种形状和凸起的测量值）之间是否存在相关性尚不清楚。在这里，我们研究了食草动物/杂食动物巨型袋鼠和暗袋熊以及专性食叶动物袋熊的牙齿微观磨损变量（包括传统的方法评估最尖锐的牙尖和新的多牙尖评估方法）与气候变量之间的关系。我们发现，下颌牙齿的牙齿微观磨损能够区分考拉和袋鼠的饮食习惯。此外，巨型袋鼠和袋熊的牙齿微观磨损与平均最低温度相关，而暗袋熊的牙齿微观磨损不受温度影响，尽管它们在分布范围内的平均最低温度和平均最高温度存在显著差异（以及在此处检查的标本）。与预期的来自较干燥地区的个体牙齿更钝和凸起更低的情况相反，牙齿微观磨损与相对干旱度的指标无关，包括年平均降水量和相对湿度。与预期的来自较干燥地区的个体牙齿更钝和凸起更低的情况相反，牙齿微观磨损与相对干旱度的指标无关，包括年平均降水量和相对湿度。与预期的来自较干燥地区的个体牙齿更钝和凸起更低的情况相反，牙齿微观磨损与相对干旱度的指标无关，包括年平均降水量和相对湿度。
