Department of Zoology, Swedish Museum of Natural History, Stockholm, Sweden.
Department of Human Evolution, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany.
PLoS One. 2019 Jul 25;14(7):e0220188. doi: 10.1371/journal.pone.0220188. eCollection 2019.
Stereoscopic microwear and 3D surface texture analyses on the cheek teeth of ten Upper Triassic to Lower Cretaceous tritylodontid (Mammaliamorpha) taxa of small/medium to large body size suggest that all were generalist feeders and none was a dietary specialist adapted to herbivory. There was no correspondence between body size and food choice. Stereomicroscopic microwear analysis revealed predominantly fine wear features with numerous small pits and less abundant fine scratches as principal components. Almost all analyzed facets bear some coarser microwear features, such as coarse scratches, large pits, puncture pits and gouges pointing to episodic feeding on harder food items or exogenous effects (contamination of food with soil grit and/or dust), or both. 3D surface texture analysis indicates predominantly fine features with large void volume, low peak densities, and various stages of roundness of the peaks. We interpret these features to indicate consumption of food items with low to moderate intrinsic abrasiveness and can exclude regular rooting, digging or caching behavior. Possible food items include plant vegetative parts, plant reproductive structures (seeds and seed-bearing organs), and invertebrates (i.e., insects). Although the tritylodontid tooth morphology and auto-occlusion suggest plants as the primary food resource, our results imply a wider dietary range including animal matter.
对产自上三叠统至下白垩统的十种体型为中小到大型的三尖叉齿兽类(哺乳形类)颊齿的立体微观磨损和 3D 表面纹理分析表明,它们都是杂食性动物,没有一种是适应草食性的专门食草动物。体型大小与食物选择之间没有对应关系。立体显微镜微观磨损分析显示,主要有细小的凹坑和较少的细划痕等精细磨损特征。几乎所有分析的牙面都有一些粗糙的微观磨损特征,如粗划痕、大凹坑、刺穿凹坑和划痕,表明它们偶尔会吃更硬的食物或受到外来物(食物中混入土壤砂粒和/或灰尘)的影响,或者两者兼有。3D 表面纹理分析表明,主要有大的空隙体积、低的峰值密度和各种阶段的圆顶的精细特征。我们将这些特征解释为食用低到中等固有磨损性的食物,可排除有规律的挖掘或贮藏行为。可能的食物包括植物的营养部分、植物的繁殖结构(种子和种子器官)和无脊椎动物(如昆虫)。尽管三尖叉齿兽类的牙齿形态和自闭塞表明植物是主要的食物来源,但我们的研究结果表明,它们的饮食范围更广,包括动物物质。