门: 节肢动物门 von Siebold, 1848
纲: 三叶虫纲 Walch, 1771
目: 莱德利基虫目 Richter, 1932
科: 莱德利基虫科 Poulsen, 1927
属: 始莱德利基虫属 Chang, 1950
种: 中间型始莱德利基虫 Lu, 1940
描述:
背部外骨骼：成年个体可达12厘米长且整体呈长卵形。头鞍向前逐渐变窄，最外部呈圆形。颈环处于中部最长，头鞍叶模糊。第一对头鞍沟向后延伸；第二、三对头鞍沟较为模糊。前鞍区与外边缘几乎等长。固定颊后方第一头鞍叶侧面具瘤点。1对轻微弯曲的长颊刺向后延伸至胸甲后部。面线前支与头甲前缘约呈80°交叉。面线后支与后边缘相交。唇瓣与喙片依附于头鞍前部边缘下方。大型的新月型眼延伸至颈沟处。胸甲共有15节体节，两侧具刺，部分第二胸节处肋刺额外延长。第九节轴环具有1笔直向后延伸的长刺。尾甲极小，由3个轴环组成。第三轴环模糊不清。翼部显示融合的体节与肋沟。
附肢：触角具有46-50个具刺的轴环，整体较长，为单肢型，位于头甲下方并向外延伸。触角后部附肢为双肢型，3对位于头甲下方，每1胸节下部各有1对。尾甲下方约有3对。每1对双肢型附肢基部由1基节与胸部相连。内肢具有7个肢节，最后1肢节具有3个爪。基节下方具有短刺。内肢肢节上也具有短刺。外肢由近端1含有约40个“细丝”的刀片状的“桨”与远端具短刚毛的“叶”组成。外肢与基节由1关节铰链连接。内肢第一肢节也与其相连。
Phylum: Arthropoda von Siebold, 1848
Class: Trilobita Walch, 1771
Order: Redlichiida Richter, 1932
Family: Redlichiidae Poulsen, 1927
Genus: Eoredlichia Chang, 1950
Specie: Eoredlichia intermediata Lu, 1940
Description:
Dorsal exoskeleton: adult dorsal exoskeleton may reach 12 cm long and looks oval in the whole shape. The head shield has a forwardly tapering glabella that is well rounded anteriorly. In front of the occipital ring, which is longest medially and which shows weak lateral lobes, the first glabellar furrow runs backward and inward before turning transversely across the central glabellar area; the second and third glabellar furrow is weaker. The preglabellar field and the anterior border are subequally long. A pair of tumor exists between the posterior of fixigena and the first glabellar lobe.A long, moderately curved cheek spine extends to at least the posterior part of the thorax. The anterior branch of the facial sutures diverge at about 80 degrees, with the posterior suture meeting the posterior margin. The hypostome and rostral plate attach beneath the anterior glabellar margin. Large crescentic eyes reach posteriorly to the neck furrow. Fifteen segments comprise the thorax; they are laterally spinose, and the ninth axial ring supports a very long posteriorly directed spine. A very small tail shield is made up of two axial rings and a weak third, and the flank area shows two fused segments and associated furrows.
Appendages: Long, uniramous antennae diverge anteriorly from underneath the head shield; each consists of 46–50 short, spine‐bearing articles. Post‐antennal appendages are biramous, with three pairs beneath the head shield, one pair underneath each of the 15 thoracic segments, and probably three pairs under the tail shield. Each biramous limb is associated proximally with a stout basal unit, the basis. The endopod consists of seven podomeres, the most distal of which is divided into three claws. The basis bears short, spinose endites on its inner margin, together with more sparse long ventral spines, and the endopod podomeres also support spines. The exopod consists of a blade‐like shaft that bears some 40 long filaments, and a distal lobe fringed with short bristles. The proximal part of the exopod is attached to the basis by a hinge joint, and the proximal part of the first podomere of the endopod is also attached to it.
时代：寒武纪第二世第三期，Eoredlichia-Wutingaspis三叶虫带（约521百万年前）。
主要产地: 云南省澄江动物群及其周边产地。
简要描述：澄江动物群中最常见的具有软躯体结构的三叶虫。
Age:
Cambrian Series 2, Stage 3, Eoredlichia-Wutingaspis Zone (approximately 521 million years ago).
Principal localities:
Chengjiang, Yunnan Province and its surrounding localities.
Brief description:
The most common trilobite with soft anatomy in Chengjiang.
Hou, X.G. et al. 2004. The Cambrian fossils of Chengjiang, China: the flowering of early animal life (Vol. 233). Oxford: Blackwell.
Hou, X.G. et al. 2008. Appendages of early Cambrian Eoredlichia (Trilobita) from the Chengjiang biota, Yunnan, China. Earth and Environmental Science Transactions of the Royal Society of Edinburgh, 99(3-4), 213-223.
Shu, D.G. et al. 1995. Redlichiacean trilobites with preserved soft‐parts from the Lower Cambrian Chengjiang Fauna (South China). In: Geyer, G. and Landing, E. (eds), Morocco ’95, The Lower‐Middle Cambrian standard of Western Gondwana, 203–241. Beringia Special Issue 2.