Peronopsis
Temporal range: earliest Mayan to earliest Batyrbayan
Itagnostus interstrictus, until recently known as Peronopsis interstricta, from the Wheeler Shale, Utah
Scientific classification
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Peronopsis

Hawle and Corda, 1847
subgenera[1]
  • Peronopsis (Peronopsis)
  • Peronopsis (Proacadagnostus) Naimark, 2012
  • Peronopsis (Svenax) Öpik, 1979
  • Peronopsis (Vulgagnostus) Naimark, 2012

and see text for species

Peronopsis (meaning "broach-like" or possibly "boot-like"[2]) is a genus of trilobite restricted to the Middle Cambrian. Its remains have been found in Asia, Australia, Europe, and North America.[1]

Etymology

The subgenus Svenax is a contraction of Sven Axel, the given names of the paleontologist Tullberg.

Taxonomy

Position of Peronopsis palmadon

Peronopsis palmadon is intermediate between Peronopsidae and Condylopygidae, but it is not clear whether P. palmadon is ancestral to the Condylopigidae, a condylopigid exhibiting regression towards ancestral characters, or an example of parallel evolution.[1]

Species previously assigned to Peronopsis

Species and distribution

Schematic showing the relationship between the different subgenera of Peronopsis (light green) with other Peronopsid genera (darker green). Unclear is the position of ?Peronopsis palmadon, a transitional form between the agnostoids and the condylopygids.

Subgenus Peronopsis (Peronopsis)

Subgenus Peronopsis (Proacadagnostus)

Subgenus Peronopsis (Svenax)

P. scutalis s.l. Salter, is recorded also from the Middle Cambrian of the Russian Federation (Mandybashskii horizon, Dolgii mys mountain, Betenev range; Tomagnostus fissus Zone, Lena River; Kounamkites Zone, Nekekit River, Khorbusuonka River, and Daldyno-Alakitshii District; Pseudanomocarina aojiformis zone, Hormustah District), Australia (Triplagnostus gibbus Zone, Sandover Beds early, Northern Territories) ; Greenland (Ptychagnostus atavus Zone, Henson Gletscher Formation; P. punctuosus Zone, Nyebö, North Greenland; Lejopyge laevigata Zone, Holm Dal Formation), Canada (Ptychagnostus atavus Zone, Saint John Formation; Paradoxides abenacus Zone, Saint Martin; both New Brunswick; P. hicksi Zone, Deep Cove, Newfoundland), Sweden (Ptychagnostus punctuosus Zone, Andrarum, Gislovshammar and Brantevik; Solenopleura s.l. brachymetopa Zone, Andrarum) and Italy (Gonnesa Formation, Sardinia). P. scutalis s.l. is also recorded from the Ford Beds, H. parvifrons Biozone, of Ford railway station, Pembrokeshire, SW Wales, described by Thomas & Jones (1912).[7]

Subgenus Peronopsis (Vulgagnostus)

Unrevised species

These species may be assigned to one of the subgenera later or be reassigned to another genus.

References

  1. ^ a b c d e f g h i j Naimark, E.B. (2012). "Hundred species of the Genus Peronopsis Hawle et Corda, 1847". Paleontological Journal. 46 (9): 945–1057. Bibcode:2012PalJ...46..945N. doi:10.1134/S0031030112090018. S2CID 85130465.
  2. ^ Jaeger, Edmund C.; Gish, Merle (1959). A source-book of biological names and terms (3rd ed., rev. ed.). Springfield, IL: Thomas. p. 189. ISBN 978-0398061791.
  3. ^ Hicks, H. 1872. "On some undescribed species from the Menevian Group with a note on the Entomostraca, by Prof. T. Rupert Jones F.G.S." Quarterly Journal of the Geological Society, London, 28, 173–185.
  4. ^ Rees, A.J.; Thomas, A.T.; Lewis, M.; Hughes, H.E.; & Turner, P. (2014). "The Cambrian of SW Wales: Towards a United Avalonian Stratigraphy". Geological Society, London, Memoirs, 42, 1–30.)
  5. ^ Illing, V.C. (1916). "The paradoxidian fauna of a part of the Stockingford Shales". Quarterly Journal of the Geological Society, London, 71 [for 1915], 386–450.
  6. ^ Gronwall, K.A., (1902): 'Bornholms Paradoxideslag og deres Fauna'. Danmarks geologiske Undersøgelse Series 2, 13, 1–230.
  7. ^ Thomas, H.H. & Jones, O.T. 1912. "On the Pre-Cambrian and Cambrian rocks of Brawdy, Hayscastle and Brimaston, Pembrokeshire." Quarterly Journal of the Geological Society, London, 68, 374–401.