门: 节肢动物门
纲: 恐虾纲
目:未定
科: 欧巴宾海蝎科
属: 欧巴宾海蝎属
种: 皇室欧巴宾海蝎
描述:
皇室欧巴宾海蝎从头到尾(含长吻)长度范围为4cm~7cm,其中长吻长1.6cm~2.8cm。欧巴宾海蝎最突出的特征就是它那中空的长吻,其总长约为身体总长的三分之一并且从头下方伸出。长吻上有条纹,就像真空吸尘器的软管一样柔软灵活,并且它的末端有刺状物,上面有五根向前或向内生长的刺。刺的左右对称和侧边结构暗示它可能是一对融合了的前端附肢,这可与放射齿目和具鳃叶足类相对比。头部有五个带茎的眼睛:两只靠近前端,离头中部还算近,看向上边和前边;两只更大的眼睛带有更长的眼柄,靠近头的后部和外部边缘,看向上方和侧边;一只单一的眼睛在更大的那对眼睛之间,看向上方。嘴巴在头下面,在吻部后边并且朝向后方以便肠道形成U形弯曲结构伸向身体后部。长吻足够长和柔韧可以直达嘴巴处。身体主体部分通常5mm宽并且分为十五节,每一节上都有一对瓣足朝向后部和外部。相邻叶状足重叠,每个叶状足的前端被前一足的后缘覆盖。身体末端是一个单一的圆锥形体节,上有三对重叠生长的尾扇,朝向上部和外部,最后是V形双扇状尾巴。
Phylum: Arthropoda
Class: Dinocaridida
Order:uncertain
Family: Opabiniidae
Genus: Opabinia
Specie: O.regalis
Description:
The length of Opabinia regalis from head (excluding proboscis) to tail end ranged between 4 centimetres (1.6 in) and 7 centimetres (2.8 in).One of the most distinctive characters of Opabinia is the hollow proboscis, whose total length was about one-third of the body's and projected down from under the head.The proboscis was striated like a vacuum cleaner's hose and flexible, and it ended with a claw-like structure whose terminal edges bore 5 spines that projected inwards and forwards.The bilateral symmetry and lateral arrangement of the claw suggest it represent a pair of fused frontal appendages, comparable to those of radiodonts and gilled lobopodians. The head bore five stalked eyes: two near the front and fairly close to the middle of the head, pointing upwards and forwards; two larger eyes with longer stalks near the rear and outer edges of the head, pointing upwards and sideways; and a single eye between the larger pair of stalked eyes, pointing upwards. It has been assumed that the eyes were all compound, like other arthropods' lateral eyes,but this reconstruction, which is not backed up by any evidence,is "somewhat fanciful".The mouth was under the head, behind the proboscis, and pointed backwards, so that the digestive tract formed a U-bend on its way towards the rear of the animal. The proboscis appeared sufficiently long and flexible to reach the mouth.The main part of the body was typically about 5 millimetres (0.20 in) wide and had 15 segments, on each of which there were pairs of flaps (lobes) pointing downwards and outwards.The flaps overlapped so that the front of each was covered by the rear edge of the one ahead of it. The body ended with what looked like a single conical segment bearing three pairs of overlapping tail fan blades that pointed up and out, forming a tail like a V-shaped double fan.
时代:中寒武纪史蒂芬组,布尔吉斯页岩段,宽钝虫-爱雷斯虫化石带双足动物群
主要产地: 伯吉斯页岩动物群(不列颠哥伦比亚省的加拿大落基山脉)
Age: The Burgess Shale member,Stephen Formation,Middle Cambrian,Pagetia bootes faunule of the Bathyuriscus-Elrathina Zone
Principal localities: The Burgess Shale fauna (the Canadian Rockies of British Columbia)
Harry Blackmore Whittington,1975.The enigmatic animal Opabinia regalis, middle Cambrian, Burgess Shale, British Columbia.The Royal Society,Volume 271,Issue 910.