Swordfish and sailfish: which came first, the sword or the sail?

Pentanogmius evolutus (originally Anaogomius or Bananogmius evolutus Cope 1877; Taverne 2004; Late Cretaceous; 1.7m long) is traditionally considered a member of the Tselfatiiformes, thought to have gone extinct in the Late Cretaceous. Here it nests with Istiophorus, the extant sailfish.

Istiophorus platypterus (Shaw 1792 in Shaw and Nodder 1792; 3m) is the extant sailfish descending from Late Cretaceous Pentanogmius. The rostrum is extended, convergent with another fast, open ocean predator, the swordfish, Xiphias. The anterior dorsal fin is larger than the lateral area of the fish itself. Teeth are absent. The pectoral fins are long and slender. The anal fin is divided in two. The vertebral column is composed of relatively few, but large vertebrae.

Xiphias gladius (Linneaus 1758; Gregory and Conrad 1937; up to 4.5m in length) is the extant swordfish, nesting between Bavarichthys and Anguilla. 1cm long hatchlings more closely resembled little eels, then growing to little sailfish before reducing the long dorsal fin. The sword is not used to spear, but to slice and maim smaller fish traveling in schools. The pelvic fins and ribs are absent, as in eels. Larger females produce more eggs, up to 29 million.