The pharyngeal jaws or maxillae of annelid worms (Annelida), commonly found in paired assemblages. They are usually black and chitinous and are known from most geologic systems.
科学参考收录了60776条科技类词条，基本涵盖了常见科技类参考文献及英语词汇的翻译，是科学学习和研究的有利工具。