Echidnocephalus

Echidnocephalus (Greek for "Echidna's head") is an extinct genus of prehistoric halosaur known from the Late Cretaceous. It is the earliest known definitive member of the order Notacanthiformes.^[2]

Close-up of skull

Echidnocephalus Temporal range: Late Campanian PreꞒ Ꞓ O S D C P T J K Pg N Possible Coniacian and Maastrichtian occurrence
Fossil of Echidnocephalus troscheli
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Actinopterygii
Order:	Notacanthiformes
Family:	Halosauridae
Genus:	†Echidnocephalus von der Marck, 1858
Type species
†Echidnocephalus troscheli von der Marck, 1858
Species[1]
†E. troscheli von der Marck, 1858 ?†E. americanus Cockerell, 1919 ?†E. pacificus Cockerell, 1919

It contains one definitive species known from complete and partial specimens: E. troscheli (=E. tenuicaudus von der Marck, 1858) from the late Campanian-aged Ahlen Formation of Westphalia, Germany.^[3] These body fossils suggest an animal already very similar to modern halosaurs.^[2]

In addition, two disputed species known only from isolated fossil scales very similar to those of modern halosaurs have been described from North America: ?E. americanus Cockerell, 1919 from the Coniacian-aged Mancos Shale of Wyoming and ?E. pacificus Cockerell, 1919 from the Maastrichtian-aged Moreno Formation of California.^[4][5]

See also

• Paleontology portal
• Fish portal

• Laytonia, a Miocene genus of fossil halosaur
• Prehistoric fish
• List of prehistoric bony fish