Rotadiscus

For the genus of snails, see Rotadiscus (gastropod).

Rotadiscus is a genus of discoidal animal known from the Cambrian Chengjiang biota^[2] and classified with the eldonioids.^[3]

Rotadiscus Temporal range: Early Cambrian – Middle Cambrian[1] PreꞒ Ꞓ O S D C P T J K Pg N
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Stem group:	Ambulacraria
Clade:	†Cambroernida
Class:	†Eldonioidea
Family:	†Rotadiscidae
Genus:	†Rotadiscus

As with other eldonioids, it was originally thought to have been pelagic, but is now thought to be benthic.

A 2023 cladistic analysis based on new fossils places Rotadiscus, along with other eldonioids, as stem-group ambulacrarians in the clade Cambroernida.^[4]

References

1. Chen, J-Y.; M-Y. Zhu; G. Q. Zhou (1995). "The early Cambrian medusiform metazoan Eldonia from the Chengjiang Lagerstätte" (PDF). Acta Palaeontologica Polonica. 40: 213–244.
2. Zhu, M.; Zhao, Yuan-Long; Chen, Jun-Yuan (2002). "Révision des animaux discoïdes cambriens Stellostomites eumorphus et Pararotadiscus guizhouensis de Chine du Sud". Geobios. 35 (2): 165–185. doi:10.1016/S0016-6995(02)00025-6.
3. Caron, J.; Conway Morris, S.; Shu, D.; Soares, D. (2010). Soares, Daphne (ed.). "Tentaculate fossils from the Cambrian of Canada (British Columbia) and China (Yunnan) interpreted as primitive deuterostomes". PLOS ONE. 5 (3): e9586. Bibcode:2010PLoSO...5.9586C. doi:10.1371/journal.pone.0009586. PMC 2833208. PMID 20221405.
4. Li, Yujing; Dunn, Frances S.; Murdock, Duncan J.E.; Guo, Jin; Rahman, Imran A.; Cong, Peiyun (May 10, 2023). "Cambrian stem-group ambulacrarians and the nature of the ancestral deuterostome". Current Biology. doi:10.1016/j.cub.2023.04.048. Retrieved 11 May 2023.