1. An artificial taxonomic category established on the basis of morphological resemblance for organisms of obscure true relationships especially fossil forms
   "The palaeontologist assigned the fossil to a form genus due to its unclear phylogenetic relationships"
    
2. (biology) an artificial taxonomic category for organisms of which the true relationships are obscure; forms the first half of a species' unique Latinate name
   "Archaeopteryx was initially placed in the form genus Archaeornis"

Type of: genus

Encyclopedia: Form genus