Adelograptus Tenellus (Linnarsson, 1871)fromthe Lower Ordovicianof Yiyang Area, Hunan Province
详细信息
- 责任者：Wang Wenhui(Department of Earth Sciences and Engineering ; Nanjing University ; Nanjing 210093) ; Feng Hongzhen
- 刊名：Acta Palaeontologica Sinica
- 出版年：2012
- 卷期：51(2)
- 页码：p.186-199
- issnNo：ISSN0001-6616
- isbnNo：CN32-1188/Q
摘要
Abundant, well-preserved graptolites were collected from the Lower Ordovician in the Nanba area of Yiyang, Hunan Province.A population analysis of Adelograptus tenellus (Linnarsson,1871) based on primary morphological characteristics such as the stipe length of each order,the number and arrangement of autothecae, and the thecal spacing realed two forms (Type Ⅰ and Type Ⅱ) in the Yiyang area. Comparing with areas such as North Europe, Great Britain and North American, an evolutionary lineage from Type Ⅰto Type Ⅱ of these two types is suggested.The results show that Adelograptus tenellus reported from Great Britain, New Zealand and Southern Anhui Province is similar to Type Ⅰ, whereas Adelograptus tenellus from Northern Europe shows a close similarity with Type Ⅱ.