Joffrichthys tanyourus, Murray & Zelenitsky & Brinkman & Neuman, 2018

† JOFFRICHTHYS TANYOURUS SP. NOV.

Holotype: TMP 2015.011 View Materials .0003, a complete fish preserved in right lateral view ( Fig. 2).

Paratype: TMP 2015.011 View Materials .0002, the anteroventral portion of a fish preserving the head and ventral body, missing the dorsal and caudal regions, preserved in right lateral view ( Fig. 3) .

Type locality and age: Paskapoo Formation, Calgary, Alberta, Canada; late Palaeocene in age.

Etymology: The specific epithet is for the Greek tany meaning long and oura meaning tail. The two previously described species are named for the shape of their dorsal and anal fins, but we name this third species for having a longer caudal peduncle than the others.

Diagnosis: Differs from † J. symmetropterus and † J. triangulpterus by having 26 abdominal vertebrae (compared to 22 in † J. symmetropterus and 23–25 in † J. triangulpterus ), falcate dorsal and anal fin (compared to rounded fin margins in † J. symmetropterus and triangular fins in † J. triangulpterus ), 11 predorsal (supraneural) bones (compared to 16 in † J.triangulpterus and 18 in † J. symmetropterus ). Further differs from † J. triangulpterus by having the pelvic fin positioned near to the centre point between the origins of the pectoral and anal fins rather than closer to the anal fin and having about four centra between the insertion of the first anal and dorsal fin pterygiophores, rather than 8–9 centra. Further differs from † J. symmetropterus by having the caudal peduncle longer than deep instead of deeper than long (unknown in † J. triangulpterus ).

DESCRIPTION