Evolutionary history of marine mollusks in warm periods

根据软体动物化石标本(特别是菊形类和鹦鹉螺类)，分析了它们的多样性和幼体大小的演化史。在白垩纪末期大灭绝期间，鹦鹉螺类幼体的大小没有变化。对古生代和中生代幼体大小的分析表明，从古生代到中生代，幼体大小逐渐增加，表明同域物种形成是其宏观演化的一个可能的主导过程。

Based on fossil specimens of mollusks(especially ammonoids and nautiloids), their evolutionary history of diversity and hatchling sizes was analyzed. The hatchling sizes in nautiloids show no change across the end-Cretaceous mass extinction. The analyses of hatchling sizes during Paleozoic and Mesozoic demonstrated that the hatchling sizes increased from Paleozoic toward Mesozoic, suggesting that sympatric speciation was a plausible dominant process of their macroevolution.