ESPECIALLY MYCTOPHOIDS 241 
LOWER CRETACEOUS : CENOMANIAN : TURONIAN : SENONIAN ‘MAAS. | 
/Hemisaurida 
9 a 
were 
ae ase i 
/ : Phylactocephalus 
/ , : 
, : z i 
1 : H : : = 
1 ee Ene hod sAApPaaA Yr > 
¥ pe : : Se 5 
1 ae Pesce 
i i >= : : A rss Palaeo| 
} y Nee ee : ; alaeolycus 
1 / xs ——- , : : 
HY SS. Gat ~>-Eurypholis—_—_——x 
/ / 2Cyl : 
ee eH 
(ay *Saurorhamphus 
jRhynchodercetis 
eres xX 
aie eSe = xo-J------------------+--------------4---------- Pelargorhynchus 
=Cimolichthys—x: 
SS , ; : 
~Prionolepis ———————————__x : 
Ape ol Ss eS 
< : ; : : : 
~ Py . : | 
~. : 
on 
AS 
\ Se 
\ cones ¢o 
\ 
i ~>-Apateopholis : 
Fic. 100. Evolutionary tree of the fossil salmoniform suborders. 
itself extends through the Upper Cretaceous and disappears at the end of the 
Senonian (Text-fig. 100). 
The Enchodontoidei is composed of two families, the Enchodontidae and Eury- 
pholidae. The genus Enchodus extended throughout the Upper Cretaceous and is 
recorded from the Tertiary (Arambourg, 1952). The divergence between the two 
families must have occurred in the Lower Cretaceous since a specialized derivative 
of the Eurypholidae, Saurorhamphus, is present in the lowermost Cenomanian. The 
genus Eurypholis is not recorded until the Middle Cenomanian and extends through 
into the Turonian. Saurorhamphus can be derived directly from Eurypholis, merely 
by slight snout and body extensions. Palaeolycus represents a specialized derivative 
of the Enchodontidae and occurs in the Upper Senonian. The origin of this genus 
can be visualized as being from one of the shallower bodied species of Enchodus, in 
which vertebral multiplication occurred. This origin was presumably in the Upper 
