Early Cretaceous Freshwater Fish Fauna in Kyushu, Japan

Early Cretaceous Freshwater Fish Fauna in Kyushu, Japan 207
In KMNH VP 100,208, the body depth is contained 2.5 times in the standard
length. The head length is contained 3.7 times in the standard length. The
number of anal fin pterygiophores is 25. Three predorsal scutes are visible. The
number of ventral scutes is 20, with 12 scutes between the pectoral and pelvic fins,
and 8 scutes between the pelvic and anal fins. The total number of vertebrae is 34,
with 18 abdominal and 16 caudal vertebrae. The number of ribs is 16. The depth
between the dorsal margin of the body and the abdominal vertebral column at the
maximum depth of the body is contained 1.9 times in the depth between the
abdominal vertebral column and the ventral margin of the body.
In KMNH VP 100,209, the body depth is contained 2.9 times in the standard
length. The head length is contained 3.7 times in the standard length. The
number of dorsal fin rays is 10. The number of anal fin rays is 23. The number of
anal fin pterygiophores is 23. Four predorsal scutes are visible. The number of
scutes between the pelvic and anal fins is 6. The total number of vertebrae is 35,
with 17 caudal vertebrae. The number of ribs is 16. The depth between the dorsal
margin of the body and the abdominal vertebral column at the maximum depth of
the body is contained 2.3 times in the depth between the abdominal vertebral column
and the ventral margin of the body.
In KMNH VP 100,210, the number of dorsal fin rays is 10. The number of
dorsal fin pterygiophores is 11. Four predorsal scutes are visible. The number of
ventral scutes is 17, with 9 scutes between the pectoral and pelvic fins, and 8 scutes
between the pelvic and anal fins. The number of ribs is 17. The depth between the
dorsal margin of the body and the abdominal vertebral column at the maximum
depth of the body is contained 2.2 times in the depth between the abdominal
vertebral column and the ventral margin of the body.
Remarks. This species is closest to Diplomystus altisomus in meristic characters and
almost same proportion. But D. kokuraensis differs from D. altisomus in the out line of
the abdomen.
The restored outline of the abdomen of D. altisomus is more convex
than that of D. kokuraensis. The body depth of D. altisomus deeper than the depth of
D. kokuraensis. The predorsal scutes are round in shape and their lengths are almost
equal to or shorter than their widths in D. kokuraensis, their lengths are almost equal
to their widths in D. altisomus.
Diplomystusaltisomus sp. nov.
(Figs. 73-77, PI. 55)
Diagnosis. It differs from other species of the genus in having the combination of
following characters. The predorsal scutes are round in shape and their lengths are
almost equal to their widths. The anterior and posterior ends of the scutes are
round. The body is remarkably deep and is contained 1.9 to 2.5 times in the