门: 节肢动物门 von Siebold, 1848
纲: 三叶虫纲 Walch, 1771
目: 耸棒头虫目 Kobayashi, 1935
科: 叉尾虫科 Kobayashi, 1935
属: 油栉虫属 Meek, 1877
种: 锯齿形油栉虫 Röminger, 1887
描述:
背部外骨骼：成年个体外骨骼可达9厘米长并整体呈椭圆形。头甲为半圆形；胸甲具有7个体节，末端具刺；尾甲半圆形，具边缘刺。头甲、胸甲与尾甲几乎等长。头鞍两侧相互平行，前端浑圆并几乎直达外边缘。细长的眼脊从头鞍前部向后弯转至向外突出弯曲的小眼处。活动颊向后逐渐变窄为笔直细长的颊刺。颊刺可延伸至第三胸节处。多刺的尾甲共有6个轴环，轴环向后依次退化变小。共有5对边缘刺向后伸出。整个外骨骼具有1个变化的具脊的颗粒状外表面和具尖端的边缘。
附肢：锯齿形油栉虫具有1对灵活多关节的头部触角。头甲触角下方含有3对双肢型附肢。内肢具有1个刀片状的多刺的基节和6个带刺的圆柱形肢节。肢节远离身体轴部逐渐变细，最后1肢节具有3个爪。外肢由内部许多扁平叠置的，从长叶伸出向后摆动的“细丝”和外部椭圆形的，发丝状的圆叶组成。相似的双肢型附肢着附于每一胸节之下。4-6对附肢依附在尾甲之上并向后逐渐变短变细。与所有保存有附肢的三叶虫不同的是，锯齿形油栉虫在尾甲最后1对附肢之后还有1对类似于触角的附肢。
Phylum: Arthropoda von Siebold, 1848
Class: Trilobita Walch, 1771
Order: Corynexochida Kobayashi, 1935
Family: Dorypygidae Kobayashi, 1935
Genus: Olenoides Meek, 1877
Specie: Olenoides serratus Röminger, 1887
Description:
Dorsal exoskeleton: adult dorsal exoskeletons may reach 9 cm long and are broadly oval in outline, with a semi-circular cephalon, a thorax of seven segments ending in spines, and a semi-circular pygidium with marginal spines. The cephalon, thorax and pygidium are of approximately equal length. The parallel-sided glabella is rounded in front and reaches almost to the anterior border. Thin eye ridges swing back from the front of the glabella to the small, outwardly-bowed eyes. The free cheeks narrow back into straight, slender genal spines reaching to the third pleurae. The spiny pygidium has six axial rings decreasing in size backwards; five pairs of marginal spines point rearward. The whole exoskeleton has a variably granulate outer surface with fine ridges and cusps near the margins.
Appendages: Olenoides serratus had a pair of flexible, multi-jointed cephalic “antennae.” Behind these, three pairs of biramous limbs were attached beneath the cephalon on either side of the mid-line. Each inner branch had a large spiny blade-shaped coxa and six spinose cylindrical podomeres that tapered away from the body, the last carrying three short “claws” at the tip. The outer limb branch was composed of many flat, overlapping filaments sweeping back from a long lobe, with a small oval, hair-fringed lobe at the outer end. Pairs of similar biramous appendages were attached under each thoracic segments; four to six pairs were attached under the pygidium, becoming shorter and more slender to the rear. Unique among all trilobites preserving limbs, Olenoides serratus also had a pair of antenna-like appendages (cerci; singular = cercus) emerging from under the pygidium behind the last biramous limbs.
时代：
寒武纪苗岭世乌溜期，Bathyuriscus-Elrathina 三叶虫带（约505百万年前）。
主要产地:
化石岭上的沃尔科特采石场。斯蒂芬山上的三叶虫床和其他产地。
简要描述：
布尔吉斯页岩中最著名的保存有双肢型附肢的三叶虫。
Age:
Cambrian Miaolingian, Wuliuan Stage, Bathyuriscus-Elrathina Zone (approximately 505 million years ago).
Principal localities:
The Walcott Quarry on Fossil Ridge. The Trilobite Beds and other localities on Mount Stephen.
Brief description:
Best known trilobites that preserved biramous appendages in Burgess Shale.
WALCOTT, C. D. 1912. Cambrian Geology and Paleontology, II. No. 6. – Middle Cambrian Branchiopoda, Malacostraca, Trilobita, and Merostomata. Smithsonian Miscellaneous Collections, 57(6): 145-228.
WHITTINGTON, H. B. 1975. Trilobites with appendages from the Middle Cambrian, Burgess Shale, British Columbia. Fossils and Strata, No. 4: 97-136.
WHITTINGTON, H. B. 1980. Exoskeleton, moult stage, appendage morphology, and habits of the Middle Cambrian trilobite Olenoides serratus. Palaeontology, 23: 171-204.