海扇类（pectinoids）在侏罗纪原大西洋的古地理分布

海扇类（pectinoids (s.l)）是一类具浮游异养幼虫类型生态特征的表生双壳类。这种生态特征决定了其大部分组成分子具世界性分布。但是，在侏罗纪原大西洋地区海扇类中仍有不少属/亚属显示出地区性特征，其地理分布主要受纬度气候带控制，即显示出南北差异。这些地区性海扇贝类是认识侏罗纪生物地理分区的重要标志。主要分布于高纬度地区的北方型分子由Buchiidae、Pectinidae和Oxytomidae 3科的一些属/亚属组成，它们于中侏罗世晚期和晚侏罗世常见于格陵兰东部，往南止于英格兰南部，是北方生物区的重要代表。适于热带－亚热带的特提斯型分子分异度较高，组成分子来自Pectinidae，Spondylidae和Entoliidae 3科，主要分布于法国以南的较低纬度地区。但是，在特提斯海扩张时期，如侏罗纪巴通期，随着特提斯生物大区北界的北移，特提斯双壳类可散布至英格兰北部。

PALAEOBIOGEOGRAPHY OF JURASSIC PECTINOIDS IN THE PROTO-ATLANTIC

Pectinoids (s.l)are a group of epifauna with planktotrophic larvae. This larval ecology has determined global distribution of majority of pectinoid bivalves. There are still some endemic genera and sub generas, which are strongly controlled by latitudes and climates. These endemic pectinoids contribute significantly to the zonation of faunal provinces of Jurassic bivalves in the Proto Atlantic. Boreal Pectinoids, indicators of higher latitudes, include some generas and sub generas of Buchiidae, Pectinidae and Oxytomidae families, which extended from eastern Greenland to southern England during the late Middle Jurassic and Late Jurassic. Tethyan taxa, restricted mainly to low latitudes with a higher diversity, consist of some generas and sub generas of Pectinidae, Spondylidae and Entoliidae families, which were distributed in the area south to France with a low latitude. During the spreading of the Tethys, however, Tethyan elements could be dispersed to England with the northward migration of the northern limit of the Tethyan Realm.