Origin, evolution and systematics of the Cretaceous ammonoid Spathites

23 4 Tue, 01/01/1980 - 12:00 December 821 837

KENNEDY, W. J., WRIGHT, C. W., HANCOCK, J. M. 1980. Origin, evolution and systematics of the Cretaceous ammonoid Spathites. Palaeontology, 23, 4, 821–837.

W. J. Kennedy, C. W. Wright and J. M. Hancock Spathites Kummel and Decker, 1954. a predominantly early to mid-Turonian genus common in Tethyan regions of both the Old and New Worlds, is a key genus in the early radiation of the Mammitinae (of which the Metoicoceratinae and Fallotitinae are shown to be synonyms). Spathitoides Wiedmann, I960 is a strict synonym and Jeanrogericeras Wiedmann, 1960 (of which Faltotites Wiedmann, i960 is a synonym) no more than subgenerically distinct. The genus evolved from Metoicoceras; a succession is demonstrated from S. (Jeanrogericeras) to S. (Spathites). Mammites is an early offshoot from the former subgenus, whilst the Coniacian Buchiceras, previously referred to the Tissotiidae, is a direct descendant of the S. (S.)rioensis Powell to S. (S.) chispaensis Kummel and Decker to S. (5.) puercoensis (Herrick and Johnson) lineage. The Palaeontological Association (Free Access)