Meeting Abstract
The actinopterygian fish nicknamed “Aphol” was a relatively common member of the Serpukhovian (Upper Mississippian) marine Bear Gulch community. The body is scaleless, low and elongate. The head is extremely narrow anteriorly and devoid of any solidly sutured or abutting bones except two paired dorsal elements. The mouth is terminal. Eye orbits are large and far forward. In all well-preserved specimens there is a flexure of the body in the mid-abdominal region. Pectoral fins are positioned vertically upright orthogonal to the body long axis. Pelvic fins are absent. A low dorsal fin extends from the fourth vertebra to the tail. A discrete anal fin is lacking but a continuous row of infrahemals extends from the first hemal arch to the beginning of the caudal fin. The tail is small, externally pointed and internally hemiheterocercal. The vertebral column is highly regionalized and strikingly specialized compared to the prevailing actinopterygian design of this age. A very flexible cervical and anterior abdominal vertebral span is followed by vertebrae with median neur- and hem-apophyses as well as pre- and post-zygaphophyses. These would render the posterior abdominal and caudal regions virtually rigid. The caudal vertebral elements and fin form a specialized complex. These characters converge upon diverse teleosts from heterocongrin and ophichthid eels to symbranchiids to thunniform swimmers. It is tantalizing to consider the life style of this enigmatic fish.
