Occacaris Explained

Occacaris oviformis is an extinct nektonic predatory arthropod from the Lower Cambrian Maotianshan shale Lagerstätte. 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.^[1]

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^[2]), 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,^[3] or to mandibulates.^[4]

See also

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

References

General references

• Book: Hou, Xian-Guang . Hou . Richard J . Jan . David J . Derek J . Feng . Xian‐Guang . Aldridge . Bergström . Siveter . Siveter . Xiang‐Hong . The Cambrian Fossils of Chengjiang, China: The Flowering of Early Animal Life . . 2004 . 10.1002/9780470999950. 9781405106733 . 88949935 .

Notes and References

1. 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 . en . 46 . 3 . 354–379 . 10.1016/j.asd.2016.10.011 . 27989966 . 1467-8039. free .
2. Jean Vannier, Jun–Yuan Chen, Di–Ying Huang, Sylvain Charbonnier & Xiu–Qiang Wang . 2006 . The Early Cambrian origin of thylacocephalan arthropods . . 51 . 2 . 201–214.
3. 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 . en . 30 . 3 . 387–397 . 10.1016/j.palwor.2020.09.002.
4. Aria . Cédric . 2022-04-26 . The origin and early evolution of arthropods . Biological Reviews . 97 . 5 . en . 1786–1809 . 10.1111/brv.12864 . 35475316 . 243269510 . 1464-7931.