科学家在南非发现一个胚胎化石, 表明产卵哺乳动物的祖先生活了2亿年前. Scientists found an embryo fossil in South Africa, suggesting egg-laying mammal ancestors lived 200 million years ago.

科学家在南非发现一个胚胎化石, 据信这是最古老的证据表明哺乳动物祖先放蛋. Scientists have discovered an embryo fossil in South Africa, believed to be the oldest evidence that mammal ancestors laid eggs. 这一发现可以追溯到大约2亿年前, 表明早期的哺乳动物类爬行动物是卵性. This finding, dating back approximately 200 million years, suggests that early mammal-like reptiles were oviparous.