Plumulites Explained

Plumulites is an extinct genus of machaeridians, extinct annelid group.[1]

Description

Plumulites is normally small animal, for example complete specimen of P. canadensis reached only 16.5mm, and P. bengtsoni being 28mm. However, several largest specimens probably reached around 15cm (06inches), making Plumulites largest machaeridians ever known.

Fossils of Plumulites were mostly known from isolated sclerites, and originally considered as arthropod or an echinoderm. However, complete sclerite assemblages of P. richorum described in 1979 has shown that this animal is more likely to be annelid worm, the group which includes modern-day earthworm, leech and bristleworm.

According to complete specimens, this animal is surrounded by pairs of outer and interior shell plates. Some of anterior outer and interior shell plates different in shape. Specimen of A. bengtsoni shows soft tissue including parapodia and chaetae.

Taxonomy

Preservation of jaw element of A. bengtsoni leads conclusion that machaeridians should be placed within the crown group of Phyllodocida.[2]

Species

As of 1929, more than 20 species have been described.[3] Subsequent studies have described many more species.

Notes and References

  1. Jakob Vinther & David Rudkin . 2010 . The first articulated specimen of Plumulites canadensis (Woodward, 1889) from the Upper Ordovician of Ontario, with a review of the anterior region of Plumulitidae (Annelida: Machaeridia) . . 53 . 2 . 327–334 . 10.1111/j.1475-4983.2010.00938.x . 2010Palgy..53..327V . free.
  2. Parry . Luke A. . Edgecombe . Gregory D. . Sykes . Dan . Vinther . Jakob . 2019-07-24 . Jaw elements in Plumulites bengtsoni confirm that machaeridians are extinct armoured scaleworms . Proceedings of the Royal Society B: Biological Sciences . 286 . 1907 . 20191247 . 10.1098/rspb.2019.1247 . 6661337 . 31337310.
  3. Book: British Museum (Natural History). . Catalogue of the Machaeridia (Turrilepas and its allies) in the Department of Geology . History) . British Museum (Natural . Withers . Thomas Henry . 1926 . London.
  4. Web site: Mindat.org . 2022-12-17 . www.mindat.org.
  5. Vinther . Jakob . Van Roy . Peter . Briggs . Derek E. G. . 2008 . Machaeridians are Palaeozoic armoured annelids . Nature . en . 451 . 7175 . 185–188 . 10.1038/nature06474 . 18185586 . 2008Natur.451..185V . 4401508 . 1476-4687.
  6. Kobayashi . Teiichi . Hamada . Takashi . 1976 . Occurrences of the Machaeridia in Japan and Malaysia . Proceedings of the Japan Academy . 52 . 7 . 371–374 . 10.2183/pjab1945.52.371. free .
  7. Choi . Duck Keun . Lee . Dong-Chan . 1992 . PLUMULITES FROM THE JIGUNSAN FORMATION (MIDDLE ORDOVICIAN) DONGJEOM AREA, KOREA . 고생물학회지 . ko . 8 . 1 . 52–58 . 1225-0929.
  8. Shaw . Alan B. . 1966 . Paleontology of Northwestern Vermont. XII. Fossils from the Ordovician Highgate Formation . Journal of Paleontology . 40 . 6 . 1312–1330 . 1301947 . 0022-3360.
  9. Högström . Anette E.S. . Ebbestad . Jan Ove R. . Suzuki . Yutaro . 2009 . Armoured annelids and molluscs from the Upper Ordovician Boda Limestone, central Sweden . GFF . en . 131 . 3 . 245–252 . 10.1080/11035890903189801 . 2009GFF...131..245H . 140672683 . 1103-5897.
  10. Choi . Duck Keun . Kim . Keon Ho . 1989 . Problematic Fossils from the Dumugol Formation(Lower Ordovician), Dongjeom Area, Korea . 지질학회지 . ko . 25 . 4 . 405–412 . 0435-4036.
  11. Candela . Y. . Crighton . W. R. B. . 2017-01-27 . Addenda to the record of machaeridian shell plates in the Wether Law Linn Formation (Late Llandovery), Pentland Hills, Scotland . Scottish Journal of Geology . 53 . 1 . 35–39 . 10.1144/sjg2016-006 . 2017ScJG...53...35C . 132750137 . 0036-9276.
  12. Jell . Peter A. . 1979 . Plumulites and the machaeridian problem . Alcheringa: An Australasian Journal of Palaeontology . en . 3 . 4 . 253–259 . 10.1080/03115517908527797 . 1979Alch....3..253J . 0311-5518.
  13. Candela . Yves . Crighton . William R. B. . 2015-01-23 . Revision of Plumulites ruskini Lamont, and new data from the Silurian of the Pentland Hills, Scotland . Scottish Journal of Geology . 51 . 1 . 31–42 . 10.1144/sjg2014-053 . 2015ScJG...51...31C . 131111779 . 0036-9276.
  14. Lefebvre . Bertrand . Van Roy . Peter . Zamora . Samuel . Gutiérrez-Marco . Juan Carlos . Nohejlová . Martina . 2022-03-31 . The Late Ordovician Tafilalt Biota, Anti-Atlas, Morocco: a high-latitude perspective on the GOBE . Geological Society, London, Special Publications . 485 . 1 . 5–35 . 10.1144/sp485-2022-29 . 2022GSLSP.485....5L . 247351043 . 0305-8719.