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

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Ecology: fast-moving nektonic carnivore