Facivermis yunnanicus (Hou & Chen, 1989), from the Early Cambrian Chengjiang Lager- st?tte, a worm-like fossil with 5 pairs of tentacles and a perceived shrunken end, has been regarded as related to polychaetes, l...Facivermis yunnanicus (Hou & Chen, 1989), from the Early Cambrian Chengjiang Lager- st?tte, a worm-like fossil with 5 pairs of tentacles and a perceived shrunken end, has been regarded as related to polychaetes, later it has been variously interpreted as lobopods, Pentastoma and lopho- phorates. Newly discovered complete specimens by the ELI field team show that the taxon has, in addition to the 5 pairs of appendages, a pear-shaped trunk end bearing two or three circles of hooks. Accordingly, based on these important morphological characters, reconsideration of its affinities is provided and the taxonomy is remedied herein. Because the five pairs of appendages of Facivermis yunnanicus resemble the appendages of the fore-trunk of lobopod Mi- raluolishania (Liu & Shu, 2004), it seems that they are homologous structures. Therefore, the affinities of Facivermis are regarded here as being close to the lobopods, in addition, the lobe-like appendages of Facivermis are very crucial to exploring the origin of the appendages of lobopods and arthropods.展开更多
基金This work was supported by the National Science Foundation of China （Grant Nos. 40332016, 30270207）the Science Foundation of Yunnan Province （2002D0033Q）the Program for Changjiang Scholar and Innovative Research Team in the University and Ministry of Science and Technology of China （Grant No. 2000077700）.
文摘Facivermis yunnanicus (Hou & Chen, 1989), from the Early Cambrian Chengjiang Lager- st?tte, a worm-like fossil with 5 pairs of tentacles and a perceived shrunken end, has been regarded as related to polychaetes, later it has been variously interpreted as lobopods, Pentastoma and lopho- phorates. Newly discovered complete specimens by the ELI field team show that the taxon has, in addition to the 5 pairs of appendages, a pear-shaped trunk end bearing two or three circles of hooks. Accordingly, based on these important morphological characters, reconsideration of its affinities is provided and the taxonomy is remedied herein. Because the five pairs of appendages of Facivermis yunnanicus resemble the appendages of the fore-trunk of lobopod Mi- raluolishania (Liu & Shu, 2004), it seems that they are homologous structures. Therefore, the affinities of Facivermis are regarded here as being close to the lobopods, in addition, the lobe-like appendages of Facivermis are very crucial to exploring the origin of the appendages of lobopods and arthropods.
