Early Cretaceous Freshwater Fish Fauna in Kyushu, Japan

Early Cretaceous Freshwater Fish Fauna in Kyushu, Japan 221
Remarks. The characteristic of the caudal skeleton of this new genus, Paraleptolepis
are follows. Anterior two uroneurals extend forward beyond the first ural centrum.
The neural arch and spine of the first preural centrum are not complete and the
rudimentary neural arch is present on the first preural centrum. Three epurals are
just behind the neural arch of the first preural centrum.
These characters indicates the relationship with the leptolepid genera, Leptolepis
and Leptolepides, and the elopiform genera, Anaethalion and Pachythrissops. But Paralepto
lepis differs from Anaethalion in the characters of the skull. The gape of the mouth is
large and the parasphenoid and maxillary teeth are present in Anaethalion (Fig. 83).
Paraleptolepis differs from Pachythrissops in the following characters. Two rudimentary
neural arches are present on the first ural centrum in Pachythrissops (Fig. 84).
Maxillary teeth are present in Pachythrissops (Fig. 85). Paraleptolepis is similar to
Leptolepis and Leptolepides in the caudal skeleton, but it differs from these genera in the
following characters. The second uroneural does not reach the preural centrum, one
rudimentary neural arch is present on the first ural centrum, and the maxilla is large
and bears small teeth on its oral margin in Leptolepis and Leptolepides. Leptolepis and
Leptolepides were once assigned to the family Leptolepidae of the order Leptolepi
formes, but the group referred to as leptolepids is not considered to be a valid
taxonomic unit (Patterson and Rosen, 1977).
smx 1-2
Fig.83. Anaethalion vidali (Sauvaoe, 1903). Cranium and pectoral girdle in left lateral
view. From Forey, 1973.