Early Cretaceous Freshwater Fish Fauna in Kyushu, Japan

Early Cretaceous Freshwater Fish Fauna in Kyushu, Japan 185
PREM
5mm
Fig. 54.
Wakinoichthys aokii gen. et sp.nov., head region of theholotype, KMNH VP100,140.
third to seventh hypurals are slender and cylindrical. The second ural centrum
bears at least three hypurals (HYU3-5). Whether the first ural centrum was
separated is unknown. Three uroneurals are visible. The first uroneural extends
forward to the first preural centrum. Epural is not visible. There are 18 principal
caudal fin rays (1,8,8,1) (Fig. 55).
Description of the paratypes from the Fourth Formation.
In KMNH VP 100,141, the number of principal dorsal fin rays is 10. There are
10 dorsal fin pterygiophores. The number of principal anal fin rays is 22. There
are 21 anal fin pterygiophores and a stay. The pelvic fin is slightly anterior to the
middle of the abdomen. The long pectoral fin extends posterior to the pelvic fin
insertion. The anterior and the posterior parts of the first ural centrum are present.
Four uroneurals are visible (Fig. 56).
In KMNH VP 100,142, there is 12 dorsal fin pterygiophores and a stay. The
number of principal anal fin rays is 21. There are 21 anal fin pterygiophores. The
pelvic fin is present. The pectoral fin extends over the pelvic fin insertion.
In KMNH VP 100,143, the number of dorsal fin pterygiophores is 10. There
are 20 principal anal fin rays and 19 anal fin pterygiophores. The pectoral fin
extends over the pelvic fin insertion. This is the largest specimen.