Anidanthus(腕足动物)的分布及其意义

DISTRIBUTION AND IMPLICATION OF ANIDANTHUS(BRACHIOPOD)

Anidanthus是凉水型腕足动物的代表之一 ,主要出现在早二叠世Sakmarian期至中二叠世Wordian期 ,先驱分子在晚石炭世的巴什基尔期已出现 ,部分种延至晚二叠世。Anidanthus主要分布于北方大区和冈瓦纳大区 ,具两极分布的特点。气候是造成Anidanthus两极分布的最主要因素。该属中、晚二叠世在特提斯区出现 ,是全球气候变冷事件的反应。

As one of the typical cool water brachiopod, Anidanthus had a main time range between Sakmarian of the early Permian and Wordian of the middle Permian. Several pioneers appeared in Bashkirian of the late Carboniferous. Some species lasted in the late Permian. Anidanthus distributes in Boreal Realm and Gondwanan Realm, which shows the feature of boreal type. Climate is the key factor that results in the pattern of the boreal distribution. The genus appeared in Tethyan Realm in middle and late Permian which implies that the global climate becoming cooler during that time.