Paleobiology of the Latest Tithonian (Late Jurassic) AmmoniteSalinites grossicostatum Inferred from Internal and External Shell Parameters Patrick Zell, Wolfgang Stinnesbeck 2016 Ontogenetic sequence reconstruction and sequence polymorphism in extinct taxa : an example using early tetrapods (Tetrapoda: Lepospondyli) Jennifer C. Olori 2013 The earliest Cenomanian ammonoid Tanabeceras yezoense (Shigeta) from the Hobetsu area, Hokkaido (PDF) Paleontological Research, vol. 16, p. 208–218. Spath, LF, 1927: Revision of the Jurassic cephalopod fauna of Kachh (Cutch), part 1. Memoires of the Geological Survey of India, Palaeontologia Indica (new series), vol. 9, p. 1–71. A New Species of the Heteromorph Ammonoid Phylloptychoceras from the Lowest Maastrichtian of Hokkaido, Japan Yasunari Shigeta [SUP]1[/SUP] and Tomohiro Nishimura [SUP]2[/SUP] [SUP]1[/SUP] Department of Geology and Paleontology, National Museum of Nature and Science, 4-1-1 Amakubo, Tsukuba, Ibaraki 305-0005, Japan (e-mail: email@example.com) [SUP]2[/SUP]Hobetsu Museum, 80-6, Hobetsu, Mukawa, Hokkaido 054-0211, Japan Abstract. A new Cretaceous heteromorph ammonoid, Phylloptychoceras horitai sp. nov., is described from the lowest Maastrichtian of Hokkaido, Japan. Its shell is ornamented with very weak, broadly rounded ribs and its suture line is characterized by a deeply incised, trifid dorsal lobe and three bifid lateral saddles with minor indentations. This occurrence suggests that Phylloptychoceras evolved in the North Pacific during late Campanian or early Maastrichtian time and then achieved worldwide distribution during late Maastrichtian time.