Traquairius spinosus
Traquairius spinosus is a cochliodont holocephalan; one of
many from the Bear Gulch Bay, and is closely related not only to Echinochimaera
but to the "ratfish" and other modern chimaeroids. It ranged to about 1
foot in length. Only two specimens are known, and both are females. The
scale is in mm.
Rows of strong, straight spikes cover the ethmoid region of the head and long, tuberculated, spinous plates lay alongside the lower jaw and under the orbit. The body was covered with very fine and sparse placoid scales. The tail is diphycercal.
The dentition is very similar to that of Traquairius nudus.
Arrows
in the rendering of the head of the type specimen point to the
mandibular spine and to blood vessels of the orbital sinus. The scale is in mm.
Reference:
- Lund, R., and E.D. Grogan, 1997. "Cochliodonts from the Mississippian Bear Gulch Limestone Heath Formation; Big Snowy Group, Chesterian) of Montana and the relationships of the Holocephali." Dinofest International Symposium, Proceedings: 477-492.