Early Cretaceous Freshwater Fish Fauna in Kyushu, Japan

Early Cretaceous Freshwater Fish Fauna in Kyushu, Japan 161
In KMNH VP 100,171, the body depth is contained 3.2 times in the standard
length. The head length is contained 4.2 times in the standard length. The first
dorsal fin pterygiophore is above the second caudal vertebra. The dorsal fin base is
contained 2.0 times in the anal fin base. The number of principal dorsal fin rays is
10. There are 10 dorsal fin pterygiophores. The number of principal anal fin rays
is 21. There are 21 anal fin pterygiophores. The total number of vertebrae is 36,
with 19 caudal vertebrae.
Remarks. This new species, Aokiichthys changae, resemble Paralycoptera wui Chang &
Chou, 1974 (Fig. 30) in having almost same number of dorsal and anal fin rays and
almost same in the proportion and the size (Tab. 3). However, it differs from P. wui
in having fewer vertebrae and ribs. The number of vertebrae is 35 to 36 with 18 to
19 caudal vertebrae in A. changae, 40 to 42 with 20 caudal vertebrae in P. wui. The
number of ribs is 14 to 15 in A. changae, 20 to 22 in P. wui (Tab. 3). A. changae is
closest to Aokiichthys toriyamai (Figs. 27-30) in having almost same meristic characters
and almost same proportion and size in the genus Aokiichthys with the exception of the
relative position of median fins (Tab. 3). The origin of the dorsal fin is vertical with
the fifth anal fin pterygiophore in A. changae. The origin of the dorsal fin is vertical
with the anal origin in A. toriyamai.
Aokiichthys otai sp. nov.
(Figs. 40-43, PI. 46)
Diagnosis. It differs from other species of the genus Aokiichthys in having the
combination of following characters. Large teeth are present on the parasphenoid.
The body is deep and the body depth is contained 2.1 to 2.4 times in the standard
length. The median fins are relatively posterior in position. The dorsal origin is
vertical with the anal origin. The number of principal dorsal fin rays is 11 to 12.
The number of principal anal fin rays is 19. The range of size is 55.3 to 60.2 mm in
standard length. The number of vertebrae is 34 to 36, with 17 to 19 caudal
vertebrae. The number of ribs is 14 to 15.
Holotype.
exposed.
KMNH VP 100,173, an almost complete specimen, with its left side
The standard length is 55.3 mm.
Paratypes. KMNH VP 100,174, an almost complete specimen with its right side
exposed, but the upper lob of the caudal fin is missing. The standard length is 60.2
mm. KMNH VP 100,175, an almost complete specimen with its left side exposed.
The standard length is 60.2 mm.
Etymology.
The species is named for Dr. Masamichi Ota who organized the first