Hadronector donbairdi
Hadronector donbairdi is a coelacanth that is closest to Allenypterus montanus in its relatively primitive skull and fin support anatomy, but conforms to the standard coelacanth bauplan. It ranges from 35 mm (1 ½ inches) to about 120 mm (4 ¾ inches) in length. It is rare, found mostly in near shore environments.
The body and the fin lobes were completely covered with round, thin, overlapping scales. The fins were webbed and supported by few, widely spaced rays. The short body, many webbed, lobed fins, and the square-cut tail indicate a good maneuverer with significant capability to accelerate quickly in short bursts.
Virtually toothless, with a mouth size intermediate between Allenypterus and Caridosuctor, Hadronector had thick lips as did all coelacanths. It was a suction feeder on rather small prey.
Special Scientific Significance:
Hadronector has a plesiomorphous skull roof and cheek bones for known coelacanths. Note the small differences in body form, tail shape, and mouth size (and habitat) between the 6 species of Bear Gulch coelacanths that define them, but more importantly give morphological evidence for the fine distinctions between their different ecological niches.
References:
- 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.