That accounts for the disappearing ichnotaxa: the creatures that made them did not survive the holocaust.
ECONOMIST: The rise of the dinosaurs
Five of the ichnotaxa disappear before the end of the Triassic, and four march confidently across the boundary into the Jurassic.
The surprise is how rapidly the new ichnotaxa appear.
英汉双解词典包含3185865条英汉词条，基本涵盖了全部常用单词的翻译及用法，是英语学习的有利工具。