Xiphactinus audax

  • North America
  • Xiphactinus audax
  • Xiphactinus vetus

Xiphactinus ( Gr. " nimble sword fish," Syn: Polygonodon, Portheus ) is a genus of large extinct predatory fish from the order of Ichthyodectiformes. Numerous fossils have been found in deposits of the Western Interior Seaway in central North America. They are dated to the Upper Cretaceous ( Turonian to Maastrichtian ).


Xiphactinus was a powerfully built fish. He had a muscular tail, with which he reached a speed of 60 km / hr. The mandible was such that he could tear open his mouth wide. The fish is distinguished by the construction of the caudal fin skeleton and a special, Ethmopalatinum mentioned bones in the nasal pit floor from all other genuine bony fish ( Teleostei ). The caudal fin is large and deeply forked, typical of fast Raiders of the free water ( pelagic zone ). Overall Xiphactinus was 5 to 6 feet long.


The first Xiphactinus fossils were found in the 1850s in Kansas, USA. Since then, it has found many copies, including a five -meter-long animal that had a complete, two -meter-long fish head first swallowed.