Department of Biological Sciences, University of Alberta, Edmonton, Alberta, T6G 2E9, Canada.
St. Joseph's College, University of Alberta, Edmonton, Alberta, T6G 2J5, Canada.
Sci Rep. 2017 Nov 17;7(1):15787. doi: 10.1038/s41598-017-16056-3.
The first histological study of an entire hadrosaurid dental battery provides a comprehensive look at tooth movement within this complex structure. Previous studies have focused on isolated teeth, or in-situ batteries, but this is the first study to examine an entire dental battery of any dinosaur. The absence of direct tooth-to-tooth contact across the entire battery and a unique arrangement of the dental tissues in hadrosaurids led us to compare their teeth with the ever-growing incisors of mammals. The similarity in the distributions of tissues along the incisor, coupled with continuous eruption, make for helpful comparisons to hadrosaurid teeth. The mammalian ever-growing incisor can be used as a model to extrapolate the soft tissue connections and eruptive mechanisms within the hadrosaurid dental battery. Serial sections across the adult dental battery reveal signs of gradual ontogenetic tooth migration. Extensive remodeling of the alveolar septa and the anteroposterior displacement of successive generations of teeth highlight the gradual migration of tooth generations within the battery. These eruptive and ontogenetic tooth movements would not be possible without a ligamentous connection between successive teeth and the jaws, underscoring the dynamic nature of one of the most unique and complex dental systems in vertebrate history.
对整个鸭嘴龙类牙齿电池的首次组织学研究提供了对这种复杂结构内牙齿运动的全面观察。以前的研究集中在孤立的牙齿或原位电池上，但这是首次研究任何恐龙的整个牙齿电池。整个电池中没有直接的牙齿对牙齿接触，以及鸭嘴龙类牙齿组织的独特排列，使我们将它们的牙齿与哺乳动物不断生长的门齿进行了比较。组织沿门齿分布的相似性，加上连续的出牙，为鸭嘴龙类牙齿提供了有帮助的比较。哺乳动物不断生长的门齿可以作为模型，推断出鸭嘴龙类牙齿内的软组织连接和出牙机制。穿过成年牙齿电池的连续切片显示出逐渐发生的个体发育牙齿迁移的迹象。牙槽间隔的广泛重塑和连续几代牙齿的前后移位突出了电池内牙齿代的逐渐迁移。如果没有连续牙齿和颌骨之间的韧带连接，这些出牙和个体发育牙齿运动是不可能的，这强调了在脊椎动物历史上最独特和复杂的牙齿系统之一中具有动态性质。
