贵州剑河寒武系第4阶、乌溜阶耙肢虾Occacaris Hou,1999的研究

Occacaris Hou,1999 from the Cambrian Stage 4 and Wuliuan Stage,Jianhe County,Guizhou Province

大型双瓣壳节肢动物耙肢虾Occacaris Hou,1999是仅产于我国云南及贵州的地区性生物属种,主要特征是壳长几毫米到几厘米不等,呈卵圆形。Occacaris共3个种:Occacaris oviformis Hou,1999、Occacaris lazizhaiensis Wen et Peng,2017和Occacaris magnus(Yao,2009)。该3个种在贵州剑河皆有产出。O.oviformis、O.lazizhaiensis和O.magnus的壳体长宽比有明显分异。O.magnus是优势种。贵州Occacaris的发现提供了该属从云南筇竹寺组(寒武纪第3期)东迁进入贵州凯里组(乌溜期)的连续地层产出证据;从杷榔组(陆棚斜坡相区较深水沉积)到凯里组(大陆斜坡沉积)均有发现,充分说明Occacaris适应了更宽的地理和生态环境。凯里组的Occacaris常与腕足类、三叶虫、软舌螺及始海百合等生物共存,为研究其生态及埋藏特征提供了重要材料。

The large bivalved arthropod Occacaris Hou,1999 is a endemic genus that is only found in Yunnan and Guizhou provinces in China,the main characteristics of the valves is a few millimeters to a few centimeters in length,with egg-shaped outline.There are three species:including Occacaris oviformis Hou,1999,Occacaris lazizhaiensis Wen et Peng,2017 and Occacaris magnus Yao,2009.The three species are all found in Jianhe County,Guizhou Province,in which O.magnus(Yao,2009)is the dominate species.The discovery of Occacaris in Guizhou provides evidence of the continuous stratigraphic production of the genus from the east of the Qiongzhusi Formation in Yunnan(Cambrian Period 3)to the Kaili Formation in Guizhou(Cambrian Wuliu Period).Occacaris recorded from the Balang Formation(continental shelf slope facies)to Kaili Formation(continental slope deposits),which shows that Occacaris has adapted to a wider geographical and ecological environment.The Occacaris in the Kaili Formation often coexist with organisms such as brachiopods,trilobites,hyolithes,and Eocrinoidea,providing important materials for studying their ecological and burial characteristics.