Abstract：
The upper and lower jaws of some wrasses (Eupercaria: Labridae) possess teeth that have been coalesced into a strong durable beak that they use to graze on hard coral skeletons, hard-shelled prey, and algae, allowing many of these species to function as important ecosystem engineers in their respective marine habitats. While the ecological impact of the beak is well understood, questions remain about its evolutionary history and the effects of this innovation on the downstream patterns of morphological evolution. Here we analyze 3D cranial shape data in a phylogenetic comparative framework and use paleoclimate modeling to reconstruct the evolution of the labrid beak across 205 species. We find that wrasses evolved beaks three times independently, once within odacines and twice within parrotfishes in the Pacific and Atlantic Oceans. We find an increase in the rate of shape evolution in the Scarus+Chlorurus+Hipposcarus (SCH) clade of parrotfishes likely driven by the evolution of the intramandibular joint. Paleoclimate modeling shows that the SCH clade of parrotfishes rapidly morphologically diversified during the middle Miocene. We hypothesize that possession of a beak in the SCH clade coupled with favorable environmental conditions allowed these species to rapidly morphologically diversify.
摘要：
一些香肠（Eupercaria：Labridae）的上颚和下颚的牙齿已合并成坚固耐用的喙，用于在坚硬的珊瑚骨骼上放牧，硬壳猎物,和藻类，允许其中许多物种在各自的海洋栖息地中充当重要的生态系统工程师。虽然喙的生态影响是众所周知的，关于其进化历史以及这种创新对形态进化下游模式的影响仍然存在疑问。在这里，我们在系统发育比较框架中分析了3D颅骨形状数据，并使用古气候模型重建了205个物种的唇喙的进化。我们发现鱼叉独立进化了三次喙，一旦在odacines中，在太平洋和大西洋的鹦鹉鱼中两次。我们发现鹦鹉的ScarusChlorurusHipposcarus（SCH）进化枝的形状演变速率增加，这可能是由下颌关节的进化驱动的。古气候模型表明，在上世纪中期，鹦鹉鱼的SCH进化枝在形态上迅速多样化。我们假设在SCH进化枝中拥有喙，再加上有利的环境条件，可以使这些物种在形态上迅速多样化。
