Chewing function and feeding adaptations in triconodont mammals

三齿兽哺乳动物的咀嚼功能和摄食适应

• 批准号: 265535948
• 负责人: Professor Dr. Thomas Martin
• 金额: --
• 依托单位: Abteilung Paläontologie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2015
• 资助国家: 德国
• 起止时间: 2014-12-31 至 2017-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/265535948?language=en
• 关键词: Chewing; function; feeding; adaptations; triconodont

The plesiomorphic molariform pattern of stem-mammals (mammaliaforms) is the triconodont condition, with an anterior-posterior alignment of the three main cusps. This molariform pattern characterizes basal mammaliaforms such as the morganucodontids with a purported insectivorous nutrition. From these basal triconodonts on one hand the evolutionary lineage with a reversed triangle pattern of molar cusps emerged, leading to modern mammals with tribosphenic teeth. This cusp arrangement of alternating triangles was predisposition for the highly differentiated dentitions of modern mammals. On the other hand, the eutriconodont lineage maintained the triconodont pattern without triangulation and further refined it. Eutriconodonts were the first mammals to develop a carnivorous adaptation by a precise occlusion of upper and lower teeth. They were successful up to the Late Cretaceous and the largest Mesozoic mammals belonged to this group (Repenomamus with up to 15 kg body mass). With the innovative Occlusal Fingerprint Analyser software tool that has been developed by our DFG research unit 771 the chewing cycle of triconodonts can be modeled three dimensionally for the first time. By a quantification of tooth contact areas during mastication the efficiency of the various tooth and types can be estimated. The aim of the project is to analyse the functional transformation from the insectivorous dentition of basal triconodonts to the carnivorous adaptation of Eutriconodonta by high resolution 3D models and a striation- and microtexture-analysis of the occlusal surfaces. Using the Occlusal Fingerprint Analyser software the mastication cycle will be modelled for the first time. Hypotheses on insectivrous and carnivorous feeding adaptations will be tested by comparison with dentitions of extant mammals. The aim of the project is besides an in-depth understanding of evolution of mastication in mammals an insight in the role of triconodonts in Mesozoic vertebrate communities.

茎哺乳动物（形目）的近形臼齿形模式是三齿型，具有前后排列的三个主要尖齿。这种臼齿状的模式是基生类的特徴，例如具有食虫性营养的摩骨齿类。一方面，从这些基底三齿龙的演化谱系中，出现了臼齿尖的反三角形模式，导致了现代哺乳动物的楔齿。这种交替三角形的尖齿排列是现代哺乳动物高度分化的齿系的倾向。另一方面，真牙形石谱系保持了三牙形石的模式，没有三角形，并进一步完善了它。真牙形石是第一种通过上下牙齿的精确咬合而发展出食肉适应的哺乳动物。他们成功地到晚白垩世和最大的中生代哺乳动物属于这个组（Repenomamus高达15公斤体重）。随着创新的咬合指纹分析软件工具，已经开发了由我们的DFG研究单位771的咀嚼周期可以模拟三维第一次。通过对咀嚼过程中牙齿接触面积的量化，可以估计各种牙齿和类型的效率。该项目的目的是通过高分辨率3D模型和咬合面的条纹和微观纹理分析，分析从基生三齿类的食虫齿系到Eutriconodonta的食肉适应的功能转变。使用咬合指纹分析软件的咀嚼周期将首次建模。食虫性和食肉性摄食适应的假设将通过与现存哺乳动物的齿系进行比较来检验。该项目的目的除了深入了解哺乳动物咀嚼的进化外，还深入了解三齿类在中生代脊椎动物群落中的作用。