Polyosteorhynchus beargulchensis
Polyosteorhynchus is a coelacanth, close to Allenypterus and Hadronector in having rather primitive skull and skeletal anatomy. They range in size from 35 mm to about 150 mm.
Large premaxillary teeth, with a mouth size between Allenypterus and Caridosuctor, it had thick lips as did all coelacanths; it was a suction feeder on rather small prey.
They have a long body with a peaked back, many webbed, lobed fins, and a rounded tail. They were completely covered with round, thin, overlapping scales. All fins are well webbed, with few, widely spaced rays. Like other coelacanths they were slow, maneuvering swimmers.
Special Scientific Significance:
Note the narrow differences in body form and mouth size between the species of Bear Gulch coelacanths that define them, and suggest their different ecological niches.
Reference:
- Lund, R., and W. L. Lund, 1984. "New genera and species of coelacanths from the Bear Gulch Limestone (Lower Carboniferous) of Montana (U.S.A.)." Geobios, 17, fasc 2: 237-244.
- Lund, R., and W.L. Lund, 1985. "Coelacanths from the Bear Gulch Limestone (Namurian) of Montana and the evolution of the Coelacanthiformes." Bull. Carnegie Mus. Nat. Hist. 25: 1-74.