Earlier we looked at another strange Bear Gulch fish,
the small chimaeirid, Belantsea. Today, we add another small specimen, Allenypterus (Fig. 1), this time from the coelacanth clade. Like Belantsea, Allenypterus is distinct from other members of its clade (e.g. Latimeria), yet not enough to nest it in another clade.
The specimen was apparently preserved
(Fig. 1) with the premaxilla and maxilla detached from the skull, but still occluding with the dentary.
Allenypterus montanus (Melton 1969; Lund and Lund 1984; 15cm long; Late Carboniferous) is a small, early coelocanth with a distinct tear-drop shape. The dorsal fins and anal fin do not have lobes. This is a derived trait.
Lund R and Lund W 1984. New genera and species of coelacanths from the Bear Gulch Limestone (Lower Carboniferous) of Montana (U.S.A.). Geobios. 17 (2): 237–244.
Melton WG 1969. A new dorypterid fish from central Montana. Northwest Science 43:196-206.