Tsinania、Dictya、Dictyites、Dictyella之间的关系(from Lei & Liu 2014)

以下英文摘抄于Qian-Ping Lei, Qing Liu, 2014, Late ontogeny of the trilobite Tsinania shanxiensis (Zhang and Wang, 1985) from the Cambrian (Furongian) of Anhui, China and its systematic implications, Palaeoworld, 23(3-4),229-239 一文。粗略译文见每段下方:

Remarks: Kobayashi (1933) established Dictya for its differentiation of the marginal border on the cranidium and pygidium plus the isoteli-form suture, which distinguish it from Tsinania. Three years later, as the name “Dictya” had already been preoccupied, Dictyites was proposed by Kobayashi to replace Dictya, and was further differentiated by the presence of distinct depressed borders on both the cranidium and pygidium (Kobayashi, 1936).

注意:Kobayashi (1933)建立Dictya,因其头盖和尾甲外边缘和等称虫式的面线与Tsinania不同。三年后“Dictya”的名字已经被占用了,Kobayashi提议使用Dictyites取代Dictya,以进一步区分其显著下凹的头盖和尾甲边缘(Kobayashi, 1936)。

However, the type specimens of Dictyites (Walcott, 1913, pl. 23, figs. 5,5a) have the same features as those of Tsinania, and all these specimens are also from the same horizon and locality, so Zhang and Jell (1987) considered that Dictyites is a junior synonym of Tsinania. After comparing their figures, we think Kobayashi (1933) chose the wrong pygidia for “Dictya dictyites” which should be assigned to another new species “D. dolichocephala” of his. In addition, whether the axial furrows are distinct or not should be observed on the testaceous specimens. So Dictyites is regarded as a junior synonym of Tsinania.

然而,Dictyites的模式标本(Walcott, 1913, pl. 23, figs. 5,5a)具有和Tsinania相同的特征,并且这些所有的标本都是来自同一层位同一地点,故Zhang and Jell (1987)认为DictyitesTsinania的晚出同物异名。通过比较其图片,我们认为Kobayashi (1933)错误的选择了“Dictya dictyites”的尾甲,其本应该是他另一新种 “D. dolichocephala”的尾甲。另外,无论轴沟是否显著,其都应在外模标本上显示出来。故Dictyites应为Tsinania的晚出同物异名。

Most characteristics of Dictyella Kobayashi, 1933 are very similar to Tsinania except for having a long posterior pygidial spine on the centre of the posterior border (Kobayashi, 1933, pl. 15, figs. 17, 18; Zhang and Wang, 1985, pl. 133, figs. 17, 18; Han and Chen, 2004, fig. 1.1-1.5).

Dictyella Kobayashi, 1933的大部分特征都和Tsinania极其相似,除了前者在后边缘具一长尾刺(Kobayashi, 1933, pl. 15, figs. 17, 18; Zhang and Wang, 1985, pl. 133, figs. 17, 18; Han and Chen, 2004, fig. 1.1-1.5).。