Department of Geosciences and Geography, University of Helsinki, Helsinki, Finland.
Proc Biol Sci. 2012 Jul 22;279(1739):2793-9. doi: 10.1098/rspb.2012.0211. Epub 2012 Mar 28.
We have recently shown that rainfall, one of the main climatic determinants of terrestrial net primary productivity (NPP), can be robustly estimated from mean molar tooth crown height (hypsodonty) of mammalian herbivores. Here, we show that another functional trait of herbivore molar surfaces, longitudinal loph count, can be similarly used to extract reasonable estimates of rainfall but also of temperature, the other main climatic determinant of terrestrial NPP. Together, molar height and the number of longitudinal lophs explain 73 per cent of the global variation in terrestrial NPP today and resolve the main terrestrial biomes in bivariate space. We explain the functional interpretation of the relationships between dental function and climate variables in terms of long- and short-term demands. We also show how the spatially and temporally dense fossil record of terrestrial mammals can be used to investigate the relationship between biodiversity and productivity under changing climates in geological time. The placement of the fossil chronofaunas in biome space suggests that they most probably represent multiple palaeobiomes, at least some of which do not correspond directly to any biomes of today's world.
我们最近表明，降雨是陆地净初级生产力（NPP）的主要气候决定因素之一，可以从哺乳动物食草动物的平均摩尔牙冠高度（高冠齿）中可靠地估算出来。在这里，我们表明食草动物臼齿表面的另一个功能特征，即纵向脊计数，也可以类似地用于提取降雨的合理估计值，以及温度的合理估计值，温度是陆地 NPP 的另一个主要气候决定因素。总的来说，摩尔高度和纵向脊的数量解释了当今全球陆地 NPP 变化的 73%，并在双变量空间中解析了主要陆地生物群系。我们根据长期和短期需求来解释牙齿功能与气候变量之间关系的功能解释。我们还展示了如何利用陆地哺乳动物时空密集的化石记录来研究地质时间内气候变化下生物多样性和生产力之间的关系。化石chronofaunas 在生物群系空间中的位置表明，它们很可能代表多个古生物群系，其中至少有一些与当今世界的任何生物群系都不直接对应。
