Offacolidae

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Offacolidae
Temporal range: Ordovician–Silurian
20200810 Offacolus kingi.png
Restoration of Offacolus
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Arthropoda
Subphylum: Chelicerata
Clade: Euchelicerata
Family: Offacolidae
Sutton et al., 2002
Type species
Offacolus kingi
Orr et al., 2000
Genera

Offacolidae is a family of basal euchelicerate arthropods from the Ordovician and Silurian of Europe, Morocco and North America. [1] [2] The family is united by several features, including paddle-like sixth post-cheliceral appendages, elongated chelicerae, and reduced first tergites, although these are apparently not unique to the clade, but instead euchelicerate or wider synapomorphies, therefore making the clade paraphyletic. Alongside this, Offacolus may be more basal than the rest of the clade, as its seventh exopod pair is unreduced and it has a bipartite telson, among other features.[ citation needed ] They share with most other euchelicerates a wide carapace, which has led to them being placed in the paraphyletic “Synziphosurina” for a long time, however more detailed studies have led to them being separated. [3]

References

  1. Lustri, Lorenzo; Antcliffe, Jonathan B.; Gueriau, Pierre; Daley, Allison C. (October 2024). "New specimens of Bunaia woodwardi Clarke, 1919 (Euchelicerata): a new member of Offacolidae providing insight supporting the Arachnomorpha". Royal Society Open Science. 11 (10). doi:10.1098/rsos.240499. PMC   11524597 . PMID   39479250.
  2. Lustri, Lorenzo; Gueriau, Pierre; Daley, Allison C. (7 May 2024). "Lower Ordovician synziphosurine reveals early euchelicerate diversity and evolution". Nature Communications. 15 (1). doi:10.1038/s41467-024-48013-w. PMC   11076625 .
  3. Lamsdell, James C. (January 2013). "Revised systematics of Palaeozoic 'horseshoe crabs' and the myth of monophyletic Xiphosura: Re-evaluating the Monophyly of Xiphosura". Zoological Journal of the Linnean Society. 167 (1): 1–27. doi:10.1111/j.1096-3642.2012.00874.x.