M ansuyia S un, and T sinania W alcott, from the F urongian of N orth C hina and the evolution of the trilobite family T sinaniidae

• Published in: Palaeontology 2014-03, Vol.57 (2), p.269-282
• Main Authors: Park, Tae‐Yoon, Kim, Ju Eon, Lee, Seung‐Bae, Choi, Duck K.
• Format: Article
• Language: English
• ISSN: 0031-0239; 1475-4983
• DOI: 10.1111/pala.12065

The F urongian trilobite family T sinaniidae is characterized by a highly effaced surface and forms an important constituent of the F urongian trilobite faunas of east G ondwana. However, the origin of the characteristic morphology of this family has remained unclear. Only recently has the tsinaniid trilobite L onchopygella megaspina been suggested to represent an intermediate stage in the evolutionary transition to other tsinaniids on the basis of the trunk segmentation. Here, we report successive occurrences of four species of the kaolishaniid genus M ansuyia and a tsinaniid trilobite T sinania canens from the F urongian (late C ambrian) C haomidian F ormation in S handong P rovince, C hina. A cladistic analysis including these taxa reveals that the four species of M ansuyia constitute stem‐group taxa to the family T sinaniidae, rendering M ansuyia and the K aolishaniidae paraphyletic. The youngest species of M ansuyia , M . taianfuensis , turns out to be the immediate sister taxon of the T sinaniidae, displaying a closely similar morphology to the tsinaniid trilobite, S hergoldia laevigata . The generic and familial boundary therefore situated between M . taianfuensis and S . laevigata .