Yahoo香港字典 搜尋

搜尋結果

1. Oxford Dictionary

   Burgess Shale

   • ph.
     a stratum of sedimentary rock exposed in the Rocky Mountains in British Columbia, Canada. The bed, dated to the Cambrian period (about 540 million years ago), is rich in well-preserved fossils of early marine invertebrates, many of which represent evolutionary lineages unknown in later times.