Occacaris

Occacaris Temporal range: Cambrian Stage 3–Mid Cambrian PreꞒ Ꞓ O S D C P T J K Pg N
Fossil drawing
Reconstruction
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Arthropoda
Order:	†Pectocaridida
Family:	†Occacarididae Hou, 1999
Genus:	†Occacaris Hou, 1999
Type species
Occacaris oviformis Hou, 1999
Other species
†Occacaris magnus (Yao, 2009) †Occacaris lazizhaiensis Wen et al., 2017

Occacaris is an extinct nektonic predatory arthropod from the Lower Cambrian Maotianshan shale Lagerstätte, known from three species.[1] It bears a superficial resemblance to the Cambrian arthropod, Canadaspis, though, was much smaller, and had a pair of "great appendages", with which it may have grasped prey. It was originally considered to belong to Megacheira, however it is questioned in later study.[2]

It had a bivalved carapace that covered most of its body, leaving only the last two tergites of its trunk, with the telson jutting out of the posterior end of the carapace, and the eyes, antennae (possibly isolated endopod[3]), and great appendages jutting out of the anterior end. The spines of the great appendages are paired, setting it apart from Forfexicaris valida and megacheirans like Fortiforceps foliosa.

Suggestions have been made that Occacaris is closely related to megacheirans,[4] or to mandibulates.[5]

See also

• Arthropod
• Cambrian explosion
• Chengjiang biota
  • List of Chengjiang Biota species by phylum

References

Footnotes

1. Zhao, Xiaoyun; Zhao, Yuanlong; Chen, Wanyi; Lan, Tian; Jian, Zongkai; College, Engineering Environmental and Resources of; Guizhou, University (2020). "Occacaris Hou,1999 from the Cambrian Stage 4 and Wuliuan Stage,Jianhe County,Guizhou Province". Journal of Guizhou University(Natural Sciences) (5): 26–34.
2. Ortega-Hernández, Javier; Janssen, Ralf; Budd, Graham E. (2017-05-01). "Origin and evolution of the panarthropod head – A palaeobiological and developmental perspective". Arthropod Structure & Development. Evolution of Segmentation. 46 (3): 354–379. doi:10.1016/j.asd.2016.10.011. ISSN 1467-8039. PMID 27989966.
3. Jean Vannier, Jun–Yuan Chen, Di–Ying Huang, Sylvain Charbonnier & Xiu–Qiang Wang (2006). "The Early Cambrian origin of thylacocephalan arthropods" (PDF). Acta Palaeontologica Polonica. 51 (2): 201–214.
4. Zeng, Han; Zhao, Fang-Chen; Yin, Zong-Jun; Zhu, Mao-Yan (September 2021). "A new early Cambrian bivalved euarthropod from Yunnan, China and general interspecific morphological and size variations in Cambrian hymenocarines". Palaeoworld. 30 (3): 387–397. doi:10.1016/j.palwor.2020.09.002.
5. Aria, Cédric (2022-04-26). "The origin and early evolution of arthropods". Biological Reviews. 97 (5): 1786–1809. doi:10.1111/brv.12864. ISSN 1464-7931. PMID 35475316. S2CID 243269510.

General references

• Hou, Xian-Guang (2004). Xian‐Guang, Hou; Aldridge, Richard J; Bergström, Jan; Siveter, David J; Siveter, Derek J; Xiang‐Hong, Feng (eds.). The Cambrian Fossils of Chengjiang, China: The Flowering of Early Animal Life. Wiley-Blackwell. doi:10.1002/9780470999950. ISBN 9781405106733. S2CID 88949935.