Zhenghecaris

Zhenghecaris Temporal range: Cambrian stage 3 PreꞒ Ꞓ O S D C P T J K Pg N
Fossils of Zhenghecaris
Reconstruction of the Head sclerite of Zhenghecaris
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	incertae sedis
Genus:	† Zhenghecaris Vannier et al., 2006 [1]
Species:	†Z. shankouensis
Binomial name
†Zhenghecaris shankouensis Vannier et al., 2006 [1]

Zhenghecaris is an extinct genus of enigmatic arthropods from the Lower Cambrian Maotianshan Shales, tentatively classified as a hurdiid (peytoiid) radiodont, ^{[2] [3] [4]} and originally as a thylacocephalan. ^[1]

Classification

The genus contains a single species, Zhenghecaris shankouensis, known from several specimens mostly preserving the carapace and eyes. These specimens measure roughly 15 cm (5.9 in) in width, which if interpreted as a thylacocephalan would make it one of the largest thylacocephalans, behind Ostenocaris , Dollocaris and Ainiktozoon , as well as the earliest since all other thylacocephalans found so far are Ordovician or younger. Better preserved fossils show that it was more similar to the domed sclerites of radiodonts such as Cambroraster , with two lateral spine processes on either side of the carapace, the eyes apparently fitting into the posterior notches but that has been disputed due to the fact that the assignment to Hurdiidae is largely based on Tauricornicaris, which is no longer interpreted as a radiodont but instead as the tergites of an arthropod of uncertain affinities. ^{[4] [5]} Additional isolated sclerites from the Chengjiang have been described as the lateral sclerites of Zhenghecaris due to their broad similarity to the P-elements of hurdiids (peytoiids), and because of their similar construction, ornamentation, and possession of two-pronged lateral spine processes. ^[2] It has also been classified conservatively as Arthropoda incertae sedis , as the fragmentary remains cannot confidently be classified further due to the lack of associated appendages or trunk elements. ^[6]

Speculative life restoration of Zhenghecaris as a hurdiid (peytoiid) radiodont, with missing anatomy based on Cambroraster

Outdated reconstruction as a thylacocephalan

References

1. Vannier, Jean; Huang, Diying; Charbonnier, Sylvain; Xiu-Qiang, Wang; Chen, Jun-Yuan (June 2006). "The Early Cambrian origin of thylacocephalan arthropods". Acta Palaeontologica Polonica. 51 (2): 201–214.
2. Zeng, Han; Zhao, Fangchen; Yin, Zongjun; Zhu, Maoyan (4 January 2017). "Morphology of diverse radiodontan head sclerites from the early Cambrian Chengjiang Lagerstätte, south-west China" . Journal of Systematic Palaeontology. 16 (1): 1–37. doi:10.1080/14772019.2016.1263685. ISSN   1477-2019.
3. Moysiuk, J.; Caron, J.-B. (14 August 2019). "A new hurdiid radiodont from the Burgess Shale evinces the exploitation of Cambrian infaunal food sources". Proceedings of the Royal Society B: Biological Sciences. 286 (1908) 20191079. doi:10.1098/rspb.2019.1079. ISSN   0962-8452. PMC   6710600 . PMID   31362637.
4. Caron, Jean-Bernard; Moysiuk, Joe (2021). "A giant nektobenthic radiodont from the Burgess Shale and the significance of hurdiid carapace diversity". R. Soc. Open Sci. 8 (9) 210664. Bibcode:2021RSOS....810664C. doi:10.1098/rsos.210664. PMC   8424305 . PMID   34527273.
5. Cong, Pei-Yun; Edgecombe, Gregory D.; Daley, Allison C.; Guo, Jin; Pates, Stephen; Hou, Xian-Guang (2018). "New radiodonts with gnathobase-like structures from the Cambrian Chengjiang biota and implications for the systematics of Radiodonta". Papers in Palaeontology. 4 (4): 605–621. doi:10.1002/spp2.1219. ISSN   2056-2802.
6. Pates, Stephen; Lerosey-Aubril, Rudy; Daley, Allison C.; Kier, Carlo; Bonino, Enrico; Ortega-Hernández, Javier (19 January 2021). "The diverse radiodont fauna from the Marjum Formation of Utah, USA (Cambrian: Drumian)". PeerJ. 9 e10509. doi: 10.7717/peerj.10509 . PMC   7821760 . PMID   33552709.