Early Cretaceous Freshwater Fish Fauna in Kyushu, Japan

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142 Yoshitaka Yabumoto slender and long. In KMNH VP 100,154, the body depth is moderate. The median fins are relatively posterior in position. The anal fin base is long. The pectoral fin reaches the pelvic insertion. The number of principal dorsal fin rays is over 11. The number of dorsal fin pterygiophores is over 10. The number of anal fin pteryg iophores is over 28. The principal dorsal fin rays are preceded by two small unbranched accessory rays. The number of pectoral fin rays is 18. The number of pelvic fin rays is 7. The total number of vertebrae is over 46 or 47, with over 26 caudal vertebrae. The anterior end of the vertebral column is not visible. The number of abdominal vertebrae was estimated on the basis of the ribs. Eighteen or nineteen ribs can be counted. There is a series of median supraneurals beginning close behind the head and ending before the dorsal pterygiophore. Each supraneu ral is slender and long. Remarks. Although the present fossils are poorly preserved, three fossils are considered to belong to a samespecies in having the following characters: 1) the long anal fin base, 2) almost same number of dorsal fin rays, and 3) same forms of the body, median supraneurals, dorsal fin, anal fin and vertebral column. It clearly shows a character to be a member of the order Ichthyodectiformes by the uroneurals covering the lateral faces of the preural centra. This species is considered to be closest to Chuhsiungichthysyanagidai in having the large dorsal fin, the same number of dorsal fin rays and the relative position of the median fins, but it differs from C. yanagidai in having larger number of vertebrae. The number of vertebrae is 46 or 47, in this species, 40 in C. yanagidai. The present author does not describe this species as a new species until better specimens are collected. Infradivision Osteoglossomorpha Order Osteoglossiformes Family Lycopteridae Genus Yungkangichthys Chang & Chou, 1974 Diagnosis. It differs from other genera of the family Lycopteridae in having the combination of following characters. The body is remarkably deep. The body depth is contained 1.7 to 2.1 times in the standard length. The number of branched caudal fin rays is 15. The outline of the abdomen rapidly ascends in front of the anal origin. The number ofvertebrae is 44, with 22 caudal vertebrae. The number of ribs is 18. The number of dorsal fin rays is 11. The number of anal fin rays is 19. Type species. Yungkangichthys hsitanensis Chang & Chou, 1974.
Early Cretaceous Freshwater Fish Fauna in Kyushu, Japan 143 Yungkangichthys macrodon sp. nov. (Figs. 26-28, PI. 43.) Diagnosis. It differs from other species of the genus Yungkangichthys in having the combination of following characters. The body is deep and the body depth is contained 1.7 times in the standard length. The length of the centrum is longer than the depth. Large canine like teeth are present on the parasphenoid. The number of abdominal vertebrae is 20. The number of ribs is 18. The estimated maximum size is over 200 mm in standard length. Holotype. KMNH VP 100,183, a specimen of the anterior part of the body, with its lateral side exposed. The caudal and dorsal parts of the body, the anterior end and the ventral part of the head region are missing. The length of the preserved portion is 73.3mm along the body axis. The estimated standard length is 205.3 mm. Locality. Kumagai (KA-0), Kokura-kita-ku (Kokura Northern Ward), Kitakyushu City, Fukuoka Prefecture, Japan. FRO PARA teeth Fig. 26. Yungkangichthys macrodon sp. nov., the holotype, KMNH VP 100,183.
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Early Cretaceous Freshwater Fish Fauna in Kyushu, Japan

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