Factors of intraspecific variability in ammonites, the example of Gassendiceras alpinum (d’Orbigny, 1850) (Hemihoplitidae, Upper Barremian)
Keywords: طبقه بندی; Ammonites; Intraspecific variability; Statistics; Taxinomy; Gassendiceras; Upper BarremianAmmonites; Variabilité intraspécifique; Statistiques; Taxinomie; Gassendiceras; Barrémien supérieur.