Cleistosphinctes [SEP] parent taxon
Cleistosphinctes
Cleistosphinctes is an extinct cephalopod genus from the ammonite order that lived during the Middle Jurassic.
"Cleistosphinctes", named by Arkell, 1953, and included in the family Perisphinctidae and superfamily Perisphinctaceae, is small, compressed, evolute, with long secondary ribs and very large asymmetric spatulate lappets that embrace the sides of the preceding whorl.
References.
- Treatise on Invertebrate Paleontology, Part L Ammonoidea; Geological Society of America and Univ of Kansas press, 5th printing, 1990. (p. L314)
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