noun 下载 🔗分享 Dimetrodon属，二叠纪食肉动物 A carnivorous synapsid, of the genus Dimetrodon, from the Permian period Examples : "While dinosaurs roamed much later, dimetrodons were fierce predators of the Permian period, easily identified by the large sail on their backs. " 虽然恐龙出现的时间要晚得多，但二叠纪的异齿龙是凶猛的掠食者，它们背上巨大的帆状物很容易辨认。 animal biology geology history period science 与AI对话词汇游戏阅读练习
