Early Cretaceous Freshwater Fish Fauna in Kyushu, Japan

212 Yoshitaka Yabumoto
ventral end and has wings both sides of the ridge. The preopercle is L-shape. The
sensory canal runs along the anterior margin of the upper limb and the dorsal margin
of the lower limb. Five branches of the canal are visible from the corner to the
anterior end of the lowerlimb. Four branchiostegal rays are visible. The opercleis
visible (Fig. 75). 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. Five predorsal scutes are visible. The ventral scutes are welldeveloped and
total 17 in number, with 10 scutes between the pectoral and pelvic fins, and 7 scutes
between the pelvic and anal fins. The total number of vertebrae is 34, with 16
caudal vertebrae (Fig. 73). The anterior end of the vertebral column is not visible.
The number ofabdominal vertebrae was estimated on the basis of the number of ribs.
The number of ribs is 16. Five median supraneurals are visible. The first preural
centrum bears the cylindrical parhypural. The neural arch and spine of the first
preural centrum are complete. The first hypural is the largest. The second hypu
ral is about one fourth of the first one in width. There are two ural centra. The
second ural centrum bears at least three hypurals. Two uroneurals are visible.
The number of epurals is 3. There is a caudal scute before the procurrent caudal fin
rays of the lower lobe (Fig. 76).
Fig. 76. Diplomystus altisomus sp. nov., caudal skeleton of the holotype, KMNH VP 100,217.