Mollisonia

Mollisonia
Temporal range: Cambrian Stage 3–Floian
Scientific classification
Kingdom:
Animalia
Phylum:
Arthropoda
Subphylum:
Chelicerata
Order:
†Mollisoniida
Genus:
†Mollisonia

Walcott, 1912
Type species
†Mollisonia symmetrica
Walcott 1912
Other species
  • †Mollisonia plenovenatrix Aria and Caron, 2019
  • †Mollisonia gracilis Walcott, 1912
  • †Mollisonia sinica Zhang et al., 2002
Synonyms

Houghtonites Raymond, 1931

Mollisonia in various views showing digestive and nervous systems

Mollisonia is an extinct genus of Cambrian arthropod, noteworthy for being among the first identified with the mouth-legs known as Chelicerae, most famously a trait of arachnids like spiders, and therefore possibly among (or ancestral to) the first chelicerates.

Species are known from the Burgess Shale, Langston Formation, and Wheeler Shale of North America, as well as the Chengjiang Biota of China.[1] Twenty-one specimens of Mollisonia are known from the Greater Phyllopod bed, where they comprise less than 0.1% of the community.[2] Remains possibly attributable to the genus are also known from the Ordovician Fezouata Formation of Morocco and Bøggild Fjord Formation in Greenland.[3]

An observation published in 2019 suggests this genus is a basal chelicerate, closer to crown group Chelicerata than members of Habeliida. It is suggested to be closely related to Corcorania, Urokodia (formerly[4]), and Thelxiope, which together form the clade Mollisoniida.[5]

  1. ^ Zhang, Xingliang; Zhao, Yuanlong; Yang, Ruidong; Shu, Degan (November 2002). "The Burgess Shale arthropod Mollisonia (M. sinica new species): new occurrence from the Middle Cambrian Kaili fauna of southwest China". Journal of Paleontology. 76 (6): 1106–1108. Bibcode:2002JPal...76.1106Z. doi:10.1017/S0022336000057917. ISSN 0022-3360. S2CID 130112985.
  2. ^ Caron, Jean-Bernard; Jackson, Donald A. (October 2006). "Taphonomy of the Greater Phyllopod Bed community, Burgess Shale". PALAIOS. 21 (5): 451–65. Bibcode:2006Palai..21..451C. doi:10.2110/palo.2003.P05-070R. JSTOR 20173022. S2CID 53646959.
  3. ^ Peel, John S.; Willman, Sebastian; Pedersen, Stig A. Schack (March 2020). "Unusual preservation of an Ordovician (Floian) arthropod from Peary Land, North Greenland (Laurentia)". PalZ. 94 (1): 41–51. doi:10.1007/s12542-019-00481-y. ISSN 0031-0220.
  4. ^ Liu, Cong; Fu, Dongjing; Wu, Yu; Zhang, Xingliang (July 2024). "Cambrian euarthropod Urokodia aequalis sheds light on the origin of Artiopoda body plan". iScience: 110443. doi:10.1016/j.isci.2024.110443. PMC 11325232.
  5. ^ Aria, Cédric; Caron, Jean-Bernard (September 2019). "A middle Cambrian arthropod with chelicerae and proto-book gills". Nature. 573 (7775): 586–589. Bibcode:2019Natur.573..586A. doi:10.1038/s41586-019-1525-4. ISSN 0028-0836. PMID 31511691. S2CID 202550431.