Weide Daniela, Betz Oliver
Institut für Evolution und Okologie, Evolutionsbiologie der Invertebraten, Eberhard Karls Universität Tübingen, Auf der Morgenstelle 28 E, Tübingen, Germany.
J Morphol. 2009 Dec;270(12):1503-23. doi: 10.1002/jmor.10773.
In insects, anatomical features of the head have been found to provide important information for phylogenetic and comparative evolutionary studies. We analyzed the internal head morphology of three (omaliine, tachyporine, oxyteline group) out of the four subfamily groups of the beetle family Staphylinidae plus two non-staphylinid outgroups (i.e., Agyrtidae and Leiodidae). Synchrotron X-ray micro-tomography was used to obtain comparative head anatomical datasets of eight species to describe (i) the presence/absence of muscles inside the head capsule and (ii) the variability in their points of origin. Nineteen of these muscles were phylogenetically informative (nine with respect to presence/absence and eleven with respect to the origin; one muscle had an influence on both analyses) and were used in character mapping analyses to reconstruct groundplan patterns of the head musculature in Staphylinidae and their subgroups. Three muscles (Mm. 7, 9, 50) were identified as possibly autapomorphic for Staphyliniformia. The taxon (Agyrtidae + Leiodidae) is supported by the absence of M. 9. The monophyly of the tachyporine group is supported by a common origin of M. 4. Aleocharinae, a subfamily within the tachyporine group, is supported by the absence of M. 42 and possibly by numerous points of origin of various muscles (Mm. 1, 17, 28, 29, 30). Our analysis of the general organization of the hypopharynx-prementum-complex has revealed that this complex is organized in a similar way in the investigated staphylinoids, i.e., with the prementum lying anteriorly to and being in line with the hypopharynx and the mentum. We have found deviating conditions in the investigated species of the Aleocharinae, in which the prementum can be largely retracted posteriorly. Consequently, it is sandwiched between the ventral mentum and the dorsal hypopharyngeal region. The hypopharyngeal region is thus lifted dorsad to a large extent, approaching the cibarial roof. This situation is paralleled by a loss of the hypopharyngeal retractor (M. 42) and a shift of origin of premental retractors (Mm. 28-30) posteriorly toward the gula.
在昆虫中，头部的解剖特征已被发现可为系统发育和比较进化研究提供重要信息。我们分析了隐翅虫科四个亚科组中的三个（隐翅虫亚科、尖腹隐翅虫亚科、尖隐翅虫组）的头部内部形态，外加两个非隐翅虫类外类群（即沼甲科和球甲科）。利用同步加速器X射线显微断层扫描技术获取了八个物种的头部解剖比较数据集，以描述（i）头壳内部肌肉的有无，以及（ii）其起源点的变异性。其中19块肌肉具有系统发育信息（9块关于有无，11块关于起源；一块肌肉对两种分析都有影响），并用于特征映射分析，以重建隐翅虫科及其亚组头部肌肉组织的基本模式。三块肌肉（第7、9、50块肌肉）被确定可能是隐翅虫类的自近裔性状。（沼甲科+球甲科）类群因没有第9块肌肉而得到支持。尖腹隐翅虫组的单系性因第4块肌肉的共同起源而得到支持。尖腹隐翅虫亚科（尖腹隐翅虫组内的一个亚科）因没有第42块肌肉以及可能因各种肌肉（第1、17、28、29、30块肌肉）的众多起源点而得到支持。我们对下咽-前颏复合体总体组织结构的分析表明，在被研究的隐翅虫类中，这个复合体的组织方式相似，即前颏位于下咽前方并与下咽和颏成一直线。我们在尖腹隐翅虫亚科的被研究物种中发现了不同情况，其中前颏可在很大程度上向后缩回。因此，它夹在腹侧的颏和背侧的下咽区域之间。下咽区域因此在很大程度上被向上抬起，接近食窦顶。这种情况伴随着下咽牵缩肌（第42块肌肉）的缺失以及前颏牵缩肌（第28 - 30块肌肉）的起源向后移向颈板。
