Anton Eric, Yavorskaya Margarita I, Beutel Rolf G
Institut Für Spezielle Zoologie Und Evolutionsbiologie, FSU Jena, Jena, 07743, Germany.
Biological Faculty, Department of Entomology, Lomonosov Moscow State University, Leninskie Gory 1-12, Moscow, Russia.
J Morphol. 2016 May;277(5):615-33. doi: 10.1002/jmor.20524. Epub 2016 Mar 7.
External and internal structures of the head of adults of Clambus are described and illustrated in detail. The results are compared with structural features found in the clambid genus Calyptomerus, in representatives of other scirtoid families, and also in species of other coleopteran suborders, notably Myxophaga. The results tentatively support the monophyly of Scirtoidea and a close relationship between Clambidae and Eucinetidae is suggested by one shared derived feature of the mandible, a long and slender apical tooth with a serrate edge. The monophyly of Clambidae is very strongly supported and Acalyptomerus is probably the sistergroup of a clade Calyptomerus + Clambinae. Potential scirtoid autapomorphies are the loss of the dorsal tentorial arms, a bulging gula, a strongly transverse labrum, and a ridge separating the mediostipes from the lacinia. However, all these features are homoplasious. The monophyly of Clambidae is supported by modifications of the head capsule which is strongly flattened and broadened, by a deep clypeofrontal incision enabling vertical antennal movements, and a series of antennal features. Synapomorphies of Clambinae + Calyptomerus (Clambidae excluding Acalyptomerus) are the conglobate body form with the ventral side of the head capsule in contact with the mesocoxae, and compound eyes integrated in the contour of the head. The completely subdivided eye is an autapomorphy of Clambus. An entire series of features is shared by Clambidae (or Scirtoidea) and Myxophaga. Most of them are apomorphies that apparently evolved independently in both groups. However, the presence of well-developed maxillary and labial glands is arguably a retained groundplan feature of Coleoptera, with parallel loss in Archostemata, Adephaga and various groups of Polyphaga.
详细描述并说明了成年克氏步甲头部的外部和内部结构，并配有插图。将这些结果与在步甲属的卡氏步甲、其他隐翅虫科代表以及其他鞘翅目亚目物种（特别是小扁甲亚目）中发现的结构特征进行了比较。结果初步支持了隐翅虫总科的单系性，并且上颚的一个共同衍生特征——具锯齿边缘的细长顶端齿，表明了步甲科和球步甲科之间存在密切关系。步甲科的单系性得到了非常有力的支持，无卡氏步甲可能是卡氏步甲属 + 步甲亚科分支的姐妹群。潜在的隐翅虫科自有衍征包括背幕骨臂的缺失、鼓起的下咽、强烈横向的上唇以及将中唇茎节与内颚叶分开的脊。然而，所有这些特征都是同形同功的。步甲科的单系性得到了头壳变化的支持，头壳强烈扁平且加宽，额唇基有深切口使触角能垂直活动，还有一系列触角特征。步甲亚科 + 卡氏步甲属（不包括无卡氏步甲的步甲科）的共同衍征是身体呈球形，头壳腹侧与中基节接触，复眼融入头部轮廓。完全细分的眼睛是克氏步甲的自有衍征。步甲科（或隐翅虫总科）和小扁甲亚目共有一整套特征。其中大多数是衍征，显然在两个类群中独立演化。然而，发达的下颚腺和唇腺的存在可以说是鞘翅目的一个保留的基型特征，在原鞘亚目、肉食亚目和多食亚目的各个类群中平行消失。
