从一篇英文文章中提取关键词，并将它们列成一个带有逗号分隔的列表。


"Scientists have discovered a new species of beetle in the Amazon rainforest. The beetle, named Xylotrechus Amazonicus, has a bright orange shell and is about the size of a thumbnail. It is believed to play an important role in pollinating the region's native plants."
Scientists, discovered, new species, beetle, Amazon rainforest, Xylotrechus Amazonicus, bright orange shell, size, thumbnail, important role, pollinating, region, native plants.