†Grammoceras (ammonite)
Cephalopoda - Ammonitida - Hildoceratidae
Synonym: Costigrammoceras Buckman 1926
Parent taxon: Grammoceratinae according to M. K. Howarth 2013
Sister taxa: Catulloceras, Dumortieria, Hudlestonia, Phlyseogrammoceras, Pleydellia, Podagrosites, Pseudogrammoceras, Pseudolillia, Shakraceras, Troitsaia, Yakounia
Subtaxa: Grammoceras normanianum, Grammoceras thouarsense
Ecology: fast-moving nektonic carnivore