Name: Polyodontidae: Protopsephurus liui
Age: Lower Cretaceous (~125 m.y.a.)
Size (25.4mm=1 inch): 170 mm long (tip of rostrum to tip of tail along backbone). Matrix: 208 mm by 114 mm
Location: Yixian Formation, Songzhangzi, Lingyuan City, Liaoning Province of China
Code: BCF001
Price: $325.00 - Sold
 Description:
The fish of the family Polyodontidae are quite primitive, and are
related to the Sturgeons. There are two extant genera: Polyodon spathula
from North America, and Psepherus gladius from China. The most distinctive
feature of both genera is the elongated "snout" or rostrum
which gives the North American example its common name of paddlefish.
The rostrum is thought to be an organ of touch in the turbid rivers
that they inhabit, while also serving as a stabilizer while the fish
swims with its mouth open, using its gill rakers to capture minute
plant and animal food. The gill rakers sieve zooplankton from the
water. A recent study has shown the rosrtum to possess electrosensory
receptors which presumably allow it to detect its prey in the murky
water. The Chinese example is found in the Yangtze River basin, has
a more cone-shaped rostrum, and is commonly referred to as the elephant
fish. This specimen is closely related to the extant Chinese taxon;
indeed, its name means "primitive Psepherus" It is the earliest
record of the family. This one is well preserved, with even the delicate
microctenoid scales and the lateral line in evidence. At 170 mm in
length, it is a typical example, although some have been reported
at nearly a meter. Many fine examples of wonderfully-preserved fossils
have come from China recently, but few fish with such detail are seen. |
