Fig. 3

a–b Neoglyphioceras subcirculare (Miller, 1981); ISS-LN-ST-025, Pa samed Formation, Late Ordovician, 6°56′N, 99°47′E, a lateral view, lirae on surface, b cross section; c–e Ophiceras connectens Schindewolf, 1954; PRC-SHM-KO-138, Chaiburi Formation, Triassic, 7º37′N, 100º5′E, c lateral view, d cross section, e ceratitic suture; f–h Xenodiscoides perplicatus (Frech, 1905); PRC-SHM-KO-060, Chaiburi Formation, Triassic, 7º37′N, 100º5′E, f lateral view, g cross section, h ceratitic suture; i, j Juvenites canadensis (Tozer, 1961); PRC-SHM-KO-081, Chaiburi Formation, Triassic, 7º37′N, 100º5′E, i lateral view, j cross section; k, l Arianites musacchi Arthaber, 1911; PRC-SHM-KO-207, Chaiburi Formation, Triassic, 7º37′N, 100º5′E, k lateral view, l cross section; m, n Epiceltites genfii Arthaber, 1911; PRC-SHM-KO-061, Chaiburi Formation, Triassic, 7º37′N, 100º5′E, m lateral view; n cross section