| dbo:abstract |
Protactinocerida is a proposed order of Late Cambrian nautiloid cephalopods. Their fossils have only been found in the Late Cambrian (late Jiangshanian to early Stage 10) of North China, a diversity pattern similar to other early cephalopod orders. They were very similar to members of the order Plectronocerida in most respects. Like plectronocerids, their shells were compressed and slightly curved, containing numerous closely-spaced septa. The connecting rings have a calciosiphonate structure, while the siphuncle is divided by narrow partitions known as diaphragms. Protactinocerids were originally differentiated from plectronocerids based on their proportionally wider siphuncle. For many proposed protactinocerid genera, this may be a misinterpretation of fossil cross-sections exposed along a shallower angle than in plectronocerid fossils. Nevertheless, a very broad siphuncle (more than half the width of the shell) does seem to be valid for at least. Another supposed distinguishing trait is the presence of calcite deposits between the diaphragms. However, it is difficult to distinguish biological calcite deposition from later diagenetic infilling, so this trait is also dubious. Some authors have suggested merging Protactinocerida into Plectronocerida in light of the uncertainty in differentiating the two orders. (en) |
| dbo:wikiPageID |
70904496 (xsd:integer) |
| dbo:wikiPageLength |
4052 (xsd:nonNegativeInteger) |
| dbo:wikiPageRevisionID |
1090560431 (xsd:integer) |
| dbo:wikiPageWikiLink |
dbr:Calcite dbr:Cambrian_Stage_10 dbr:Genus dbr:North_China_Craton dbc:Prehistoric_cephalopod_orders dbr:Cephalopod dbc:Furongian_extinctions dbc:Prehistoric_nautiloids dbr:Late_Cambrian dbr:Septum_(cephalopod) dbr:Diagenesis dbc:Furongian_first_appearances dbr:Jiangshanian dbr:Plectronocerida dbr:Nautiloid dbr:Siphuncle dbr:Connecting_ring dbr:Benxioceras dbr:Mastoceras dbr:Physalactinoceras dbr:Protactinoceras dbr:Sinoeremoceras dbr:Wanwanoceras |
| dbp:authority |
Chen et al., 1979 (en) |
| dbp:subdivision |
Protactinoceridae *Benxioceras *Mastoceras *Physalactinoceras *Protactinoceras *Sinoeremoceras *Wanwanoceras (en) |
| dbp:subdivisionRanks |
Genera (en) |
| dbp:taxon |
Protactinocerida (en) |
| dbp:wikiPageUsesTemplate |
dbt:Automatic_taxobox dbt:Reflist dbt:Short_description dbt:Fossil_range |
| dcterms:subject |
dbc:Prehistoric_cephalopod_orders dbc:Furongian_extinctions dbc:Prehistoric_nautiloids dbc:Furongian_first_appearances |
| rdfs:comment |
Protactinocerida is a proposed order of Late Cambrian nautiloid cephalopods. Their fossils have only been found in the Late Cambrian (late Jiangshanian to early Stage 10) of North China, a diversity pattern similar to other early cephalopod orders. (en) |
| rdfs:label |
Protactinocerida (en) |
| owl:sameAs |
wikidata:Protactinocerida https://global.dbpedia.org/id/3F7Fw |
| prov:wasDerivedFrom |
wikipedia-en:Protactinocerida?oldid=1090560431&ns=0 |
| foaf:isPrimaryTopicOf |
wikipedia-en:Protactinocerida |
| is dbo:wikiPageRedirects of |
dbr:Protactinoceratida |
| is dbo:wikiPageWikiLink of |
dbr:Cephalopod dbr:Actinocerida dbr:Plectronoceratoidea dbr:Plectronocerida dbr:Nautiloid dbr:Protactinoceratida |
| is foaf:primaryTopic of |
wikipedia-en:Protactinocerida |