Paradnatoceras [SEP] parent taxon
Paradnatoceras
Paradnatoceras is an extinct straight-shelled cephalopod genus that lived in what would become China during the Ordovician from 478.6 to about 461 mya, existing for approximately 17.6 Ma.
Taxonomy.
"Paradnatoceras" is included in the Orthocerida according to Sepkoski (2002). Inclusion of the Orthocerida in the subclass Orthoceratoidea is according to more recent taxonomic opinion. In older taxonomies,e.g., the Orthocerida were included in the Nautiloidea.
Morphology.
The shell is usually long, and may be straight ("
Taxon in disguise
In bacteriology, a taxon in disguise is a species, genus or higher unit of biological classification whose evolutionary history reveals has evolved from another unit of similar or lower rank, making the parent unit paraphyletic. This happens when rapid evolution makes a new species appear radically different from the ancestral group, so that it is not (initially) recognised as belonging to the parent phylogenetic group, leaving the latter an evolutionary grade.
While the term is from bacteriology, parallel examples are found throughout the tree of