Zelandites Marshall, 1926

Raffi, María E., Olivero, Eduardo B. & Milanese, Florencia N., 2019, The gaudryceratid ammonoids from the Upper Cretaceous of the James Ross Basin, Antarctica, Acta Palaeontologica Polonica 64 (3), pp. 523-542 : 538

Genus Zelandites Marshall, 1926

Type species: Zelandites kaiparaensis Marshall, 1926 ; Upper Cretaceous of New Zealand .

Remarks. —For synonymy and diagnosis see Hoffmann 2015: 18. The holotype of the type species Zelandites kaiparaensis Marshall, 1926 ( Marshall 1926: pl. 31: 1) was lost, later Henderson (1970) designated from the original Marshall’s type series a poorly preserved specimen as a lectotype. Marshall (1926), and later Collignon (1956) and Matsumoto (1938), compared the neanic stage of Zelandites with Mesogaudryceras Spath, 1927 due to their similar morphological features. We do not concur with Hoffmann (2010) who interpreted Zelandites as the microconch of Anagaudryceras . Even though our specimens have a strongly ornamented neanoconch, a feature that clearly links Zelandites with Gaudryceras and Anagaudryceras , the ontogenetic development of Zelandites differs markedly from that of Anagaudryceras .

Zelandites is the lesser represented gaudryceratid genus in Antarctica, only three specimens of Z. varuna were described from the Maastrichtian of López de Bertodano Formation ( Macellari, 1986) and now we add four specimens of Z. pujatoi Raffi and Olivero sp. nov. from the early Campanian of the Rabot and Santa Marta formations .