Zhongxiniscus
Zhongxiniscus is a genus of primitive chordate from eastern Yunnan that lived during the Early Cambrian. Known from a single specimen, it had a small, broad and short, fish-like body that was roughly ten millimeters in length. It possessed S-shaped myomeres, numbering roughly seven per one millimeter of length. Two triangular fins are evident on the dorsal margin.
| Zhongxiniscus Temporal range: Cambrian Stage 3, | |
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| Artist's reconstruction of Zhongxiniscus. | |
| Scientific classification | |
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| Phylum: | |
| Genus: | Zhongxiniscus |
| Species: | Z. intermedius |
| Binomial name | |
| Zhongxiniscus intermedius Luo, Hu, 2001. | |
Evolutionary relationships
When compared to other Cambrian chordates like the possible cephalochordate Cathaymyrus and the two known vertebrates Haikouichthys and Myllokunmingia, Zhongxiniscus resembles Cathaymyrus in having S-shaped myomeres, but is different in having a dorsal fin and a shorter body. Zhongxiniscus approaches in form to Haikouichthys and Myllokunmingia in its myomeres and its dorsal fin, but differs from the latter two having zigzag myomeres and fin rays, which Zhongxiniscus evidently lacks.
For these reasons, Zhongxiniscus is tentatively considered to be an intermediate form between Cathaymyrus and the two vertebrates Haikouichthys and Myllokunmingia.
References
- Yang, C.; Li, X.-H.; Zhu, M.; Condon, D. J.; Chen, J. (2018). "Geochronological constraint on the Cambrian Chengjiang biota, South China" (PDF). Journal of the Geological Society. 175 (4): 659–666. Bibcode:2018JGSoc.175..659Y. doi:10.1144/jgs2017-103. ISSN 0016-7649. S2CID 135091168.
Sources
- Luo, Huilin; Hu, Sinxue; Chen, Liangzhong (Dec 2001). "New Early Cambrian Chordates from Haikou, Kunming". Acta Geologica Sinica. 75 (4): 345–348. doi:10.1111/j.1755-6724.2001.tb00051.x. S2CID 84505454.