Plumulites is an extinct genus of machaeridians, an extinct annelid group.
Description
Plumulites is normally small animal, for example complete specimen of P. canadensis reached only , and P. bengtsoni being . However, several largest specimens probably reached around , 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 P. bengtsoni shows soft tissue including parapodia and chaetae.
Taxonomy
Preservation of jaw element of P. bengtsoni leads conclusion that machaeridians should be placed within the crown group of Phyllodocida.
Species
As of 1929, more than 20 species have been described. Subsequent studies have described many more species.
- P. canadensis <small>Woodward, 1889 (type)</small> Ottawa, Canada, Katian (Upper Ordovician)
- P. australis <small>Talent, 1963</small>
- P. bengtsoni <small>Vinther, Van Roy & Briggs, 2008</small> Fezouata Formation, Morocco, Upper Tremadocian (Lower Ordovician)
- P. bohemicus <small>Barrande, 1868</small> Bohemia, Czech Republic, Lower Ordovician
- P. chikunensis <small>Kobayashi, 1934</small> Chikunsan shale (Jigunsan Formation), South Korea, Llandeilian (Middle Ordovician)
- "P". clarki <small>Shaw, 1966</small> (=?P. mobergi <small>Clark, 1924</small>) Highgate Formation, Vermont, USA, Lower Ordovician
- P. compar <small>Barrande, 1872</small> Bohemia, Czech Republic, Lower Ordovician
- P. contarius <small>Barrande, 1872</small> Bohemia, Czech Republic, Lower Ordovician
- P. dalecarlicus <small>Moberg, 1914</small> Scania, Sweden, Middle Ordovician
- P. delicatus <small>Barrande, 1872</small> Bohemia, Czech Republic, Lower Silurian
- P. devonicus <small>J. M. Clarke, 1882</small> Hamilton group, New York, USA, Middle Devonian
- P. discretus <small>Barrande, 1872</small> Bohemia, Czech Republic, Lower Silurian
- P. esthonicus <small>Withers, 1921</small> Jewe Station, Esthonia, Middle Ordovician
- P. eueides <small>Högström et al., 2008</small> Boda Limestone, Siljan district, Sweden, Lower Ordovician (KatianâÂÂHirnantian)
- P. folliculum <small>Barrande, 1868</small> Bohemia, Czech Republic, Lower Ordovician
- P. fraternus <small>Barrande, 1872</small> Bohemia, Czech Republic, Middle Ordovician
- P. gracillimus <small>Ringueberg, 1888</small> Rochester Shale, New York, USA, Middle Silurian
- P. gumunsoensis <small>Choi & Kim, 1989</small> Dumugol Formation, South Korea, Upper Tremadocian
- P. kutscheri <small>Schrank, 1978</small> Germany, Upper Wenlock Epoch (Silurian)
- P. lamonti <small>Candela & Crighton, 2017</small> Law Linn Formation, Pentland Hills, Scotland, Telychian (Silurian)
- P. llanvirnensis <small>Withers & Henry, 1926</small> Pembrokeshire, Wales, United Kingdom, Skiddavian (Lower Ordovician)
- P. malayensis <small>Kobayashi & Hamada, 1976</small> Pulau Langgon, Langkawi Islands, Malaysia, Upper Ordovician
- P. minumus <small>Barrande, 1872</small> Bohemia, Czech Republic, Lower Silurian
- P. mitchelli <small>R. Etheridge, 1890</small> Bowning Creek, New South Wales, Australia, ?Wenlock Epoch (Silurian)
- P. mobergi <small>T. H. Clark, 1924</small> Quebec, Canada, Lower Ordovician
- P. ornatus <small>Chapman, 1910</small> Victoria, Australia, Melbournian (Silurian)
- P. peachi <small>Nicholson & Etheridge, 1880</small> Ayrshire, Scotland, Ashgillian (Upper Ordovician)
- P. primus <small>Kobayashi, 1934</small> Dumugol Formation, South Korea, Upper Tremadocian
- P. pygmaeus <small>Moberg, 1914</small> Dalarna, Sweden, Lower Silurian
- P. rastritum <small>Moberg, 1914</small> Dalarna, Sweden, Lower Silurian
- P. regius <small>Barrande, 1872</small> Bohemia, Czech Republic, Middle-Upper Ordovician
- P. richorum <small>Jell, 1979</small> Humevale Formation, Victoria, Australia, Early Devonian
- P. ruskini <small>Lamont, 1978</small> Wether Law Linn Formation, Pentland Hills, Scotland, Telychian (Silurian)
- P. scoticus <small>R. Etheridge, 1878</small> Balclatchie group, Ayrshire, Scotland, Caradocian (Upper Ordovician)
- P. tafennaensis <small>Chauvel, 1967</small> Morocco, Caradoc (Upper Ordovician) and Tafilalt Biota, Morocco, Katian (Upper Ordovician)
- P. törnquisti <small>Moberg, 1914</small> Dalarna, Sweden, Middle Ordovician
- P. trentonensis <small>Withers & Henry, 1926</small> Middle Trenton Beds, New York, USA, Middle Ordovician
- P. yeringiae <small>Chapman, 1910</small> Victoria, Australia, Yeringian (Silurian)
References
External links