Riocerida (original) (raw)
Riocerida, originally named as Rioceratida, is an extinct order of Ordovician nautiloid cephalopods. They were the earliest-diverging members of the major group Orthoceratoidea, with which they share dorsomyarian muscle scars (a few large muscle scars concentrated at the top of the body chamber). However, they also possess several plesiomorphic ("primitive") traits which are absent in other orthoceratoids: Cameral and endosiphuncular deposits are absent, and the siphuncle has a marginal position along the lower edge of the shell. The conch (external shell) shape is slender, usually orthoconic (straight) or weakly cyrtoconic (slightly curved). The monophyly of Riocerida as a unique group is plausible but difficult to confirm, and they may instead be a paraphyletic grade or polyphyletic asse
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| dbo:abstract | Riocerida, originally named as Rioceratida, is an extinct order of Ordovician nautiloid cephalopods. They were the earliest-diverging members of the major group Orthoceratoidea, with which they share dorsomyarian muscle scars (a few large muscle scars concentrated at the top of the body chamber). However, they also possess several plesiomorphic ("primitive") traits which are absent in other orthoceratoids: Cameral and endosiphuncular deposits are absent, and the siphuncle has a marginal position along the lower edge of the shell. The conch (external shell) shape is slender, usually orthoconic (straight) or weakly cyrtoconic (slightly curved). The monophyly of Riocerida as a unique group is plausible but difficult to confirm, and they may instead be a paraphyletic grade or polyphyletic assemblage ancestral to all later orthoceratoids. (en) |
| dbo:wikiPageID | 70918547 (xsd:integer) |
| dbo:wikiPageLength | 2582 (xsd:nonNegativeInteger) |
| dbo:wikiPageRevisionID | 1090876065 (xsd:integer) |
| dbo:wikiPageWikiLink | dbr:Monophyly dbr:Orthocone dbc:Early_Ordovician_first_appearances dbc:Prehistoric_cephalopod_orders dbr:Cephalopod dbc:Late_Ordovician_extinctions dbc:Prehistoric_nautiloids dbc:Orthoceratoidea dbr:Endosiphuncular_deposits dbr:Nautiloid dbr:Ordovician dbr:Orthoceratoidea dbr:Evolutionary_grade dbr:Polyphyly dbr:Siphuncle dbr:Paraphyletic dbr:Bactroceratidae dbr:Body_chamber dbr:Cameral_deposit dbr:Plesiomorphic dbr:Rioceratidae |
| dbp:authority | King & Evans, 2019 (en) |
| dbp:subdivision | *Bactroceratidae *Rioceratidae (en) |
| dbp:subdivisionRanks | Families (en) |
| dbp:taxon | Riocerida (en) |
| dbp:wikiPageUsesTemplate | dbt:Automatic_taxobox dbt:Reflist dbt:Short_description dbt:Fossil_range |
| dcterms:subject | dbc:Early_Ordovician_first_appearances dbc:Prehistoric_cephalopod_orders dbc:Late_Ordovician_extinctions dbc:Prehistoric_nautiloids dbc:Orthoceratoidea |
| rdfs:comment | Riocerida, originally named as Rioceratida, is an extinct order of Ordovician nautiloid cephalopods. They were the earliest-diverging members of the major group Orthoceratoidea, with which they share dorsomyarian muscle scars (a few large muscle scars concentrated at the top of the body chamber). However, they also possess several plesiomorphic ("primitive") traits which are absent in other orthoceratoids: Cameral and endosiphuncular deposits are absent, and the siphuncle has a marginal position along the lower edge of the shell. The conch (external shell) shape is slender, usually orthoconic (straight) or weakly cyrtoconic (slightly curved). The monophyly of Riocerida as a unique group is plausible but difficult to confirm, and they may instead be a paraphyletic grade or polyphyletic asse (en) |
| rdfs:label | Riocerida (en) |
| owl:sameAs | wikidata:Riocerida https://global.dbpedia.org/id/GSzAT |
| prov:wasDerivedFrom | wikipedia-en:Riocerida?oldid=1090876065&ns=0 |
| foaf:isPrimaryTopicOf | wikipedia-en:Riocerida |
| is dbo:wikiPageRedirects of | dbr:Rioceratida |
| is dbo:wikiPageWikiLink of | dbr:Nautiloid dbr:Orthoceratoidea dbr:Rioceratida |
| is foaf:primaryTopic of | wikipedia-en:Riocerida |