일반명 : 절지동물(Bivalved Arthropoda) Isoxys

학명 : Isoxys curvirostratus (Vannier & Chen, 2000)

지질시대 : 전기캄브리아기(Lower Cambrian, 525-520 million years ago)

지층 : Qiongzhusi Formation

원산지 : Maotianshan Hill, Chengjiang County, Yunnan Province, China.

크기(Size) : 26 mm by 12 mm on a 84 mm by 61 mm matrix

생물군 : Chengjiang biota(at least some 10 million years earlier than the Burgess Shale)

비고 : 이삭시스(Isoxys)는 부족류타입(Bivalved Arthropod)의 갑각류로 자유수영을 하는 포식자였을 것으로 보고 있다. 이들은 머리부분에 커다란 한쌍의 예리한 눈을 가지고 있었으며 2개의 커다란 부속지를 가지고 있다.

첸지앙생물군에서 발견되는 조개형절지동물(bivalved arthropod) 은 3종이 보고되고 있다.

Isoxys auritus (Jiang, 1982)

Isoxys curvirostratus (Vannier & Chen, 2000)

Isoxys paradoxus (Hou, 1987)

The Maotianshan shale is a lower Cambrian Konservat Lagerstätte named for Maotianshan Hill (simplified Chinese: 帽天山; traditional Chinese: 帽天山; pinyin: Màotiānshān) in Chengjiang County, Yunnan Province, China. More commonly, the extremely diverse assemblage of organisms are referred to as the Chengjiang biota for the multiple scattered fossil sites in Chengjiang, and more simply still, just Chengjiang. The Chengjiang fauna occur in outcrops of the Qiongzhusi Formation that date to between 525 and 520 million years ago, a period the lies about the middle of the early Cambrian epoch, at least some 10 million years earlier than the Burgess Shale. The Maotianshan shale is one of some forty Cambrian fossil locations worldwide exhibiting exquisite preservation of rarely preserved, non-mineralized soft tissue, comparable to the fossils of the Burgess Shale.