A new method for reconstructing brain morphology: applying the brain-neurocranial spatial relationship in an extant lungfish to a fossil endocast

Lungfish first appeared in the geological record over 410 million years ago and are the closest living group of fish to the tetrapods. Palaeoneurological investigations into the group show that unlike numerous other fishes—but more similar to those in tetrapods—lungfish appear to have had a close fit between the brain and the cranial cavity that housed it. As such, researchers can use the endocast of fossil taxa (an internal cast of the cranial cavity) both as a source of morphological data but also to aid in developing functional and phylogenetic implications about the group. Using fossil endocast data from a three-dimensional-preserved Late Devonian lungfish from the Gogo Formation, Rhinodipterus, and the brain-neurocranial relationship in the extant Australian lungfish, Neoceratodus, we herein present the first virtually reconstructed brain of a fossil lungfish. Computed tomographic data and a newly developed ‘brain-warping’ method are used in conjunction with our own distance map so...肺鱼（lungfish）的地质记录首次出现距今已超4.1亿年，是现生鱼类中与四足动物（tetrapods）亲缘关系最近的类群。针对该类群的古神经学（palaeoneurological）研究显示，与多数其他鱼类不同，但更接近四足动物，肺鱼的脑部与其容纳该脑部的颅腔贴合度极高。据此，研究人员既可利用化石类群的颅腔铸型（endocast，即颅腔内部铸模）获取形态学数据，也可借助其推导该类群的功能与系统发育演化意义。本研究依托采自戈戈组（Gogo Formation）晚泥盆世的三维保存化石肺鱼Rhinodipterus的颅腔铸型数据，结合现生澳洲肺鱼Neoceratodus（角齿鱼属）的脑-颅腔关系，首次完成了化石肺鱼的虚拟脑重建。本研究将计算机断层扫描（computed tomographic）数据与新开发的“脑形变（brain-warping）”方法、自研的距离映射算法相结合……