Early Cretaceous Freshwater Fish Fauna in Kyushu, Japan

170 Yoshitaka Yabumoto
PREM
Fig. 46. Aokiichthys uyenoi gen. et sp. nov., head region of the holotype, KMNH VP 100,176.
Description of the holotype.
The body is deep. The body depth is contained 2.1 times in the standard
length. The head length is contained 3.2 times in the standard length. The snout
is rounded. The outline of the head dorsal margin is slightly convex. The outline
from the occipital region to the dorsal origin is almost straight (Fig. 44). The
restored outline of the abdomen is remarkably convex and runs little under the lower
end of each rib (Fig. 45).
The median fins are relatively posterior in position. The dorsal origin is behind
the anal origin and vertical with the fourth anal pterygiophore. The first dorsal fin
pterygiophore is above the first caudal vertebra. The dorsal fin base is contained 2.3
times in the anal fin base. The pectoral fin elongates and extends over the pelvic
insertion. The caudal fin is emarginate. The number of principal dorsal fin rays is
9. There are 11 dorsal fin pterygiophores. The number of principal anal fin rays is
21. There are 20 anal fin pterygiophores. The principal dorsal fin rays are
preceded by one small unbranched accessory ray. The principal anal fin rays are
preceded by one small unbranched accessory ray. Seven pectoral fin rays are
visible. There are 17 principal caudal fin rays (1,7,8,1).
The gape of the mouth is large. The lower jaw is long and narrow. The
dentary bears small canine like teeth. The suture between the dentary and anglo-