226 UPPER CRETACEOUS LEE BOSTs 
Certain features shown by Sardinius would appear to be in a less advanced condi- 
tion than those shown in the Sardinioides-Aulopus complex, and yet others appear 
to be more advanced. The more primitive features are : 
1. Pectoral fin low on flank with as many as 22 rays. 
2. Pelvic fins abdominal with 11 rays. 
3. Five or six accessory radials present in advance of the dorsal fin. 
The more advanced features are : 
1. No posterior expansion of the maxilla. 
2. No supramaxillae. 
3. Much widened gape with the jaw articulation positioned posterior to the 
occiput. 
4. No fulcral scales at the base of the tail. 
5. No pelvic splint bones. 
6. Markedly ctenoid scales. 
Sardimius from the above considerations seems to have been possibly an early 
offshoot from either the myctophiform lineage or the group of Salmoniformes from 
which the Myctophiformes were derived. It is obviously much closer to the mycto- 
phiforms than to any of the other salmoniform groups so far considered, e.g. encho- 
dontoids, halecoids. The evolution of Savdinius appears to have paralleled that of 
the myctophiforms in that some basic myctophiform characters occur together with 
some more advanced characters while several ‘ premyctophiform ’ features are still 
retained, the overall impression being not unlike the Myctophidae. 
An additional genus appended here is Volcichthys, with the type and only species 
Volcichthys dainellii d’ Erasmo (1946), from the Lower Cenomanian of Volci in Comen. 
This genus was placed by d’Erasmo (1946) in the Enchodontidae, but it most 
certainly has no affinity with these. From a consideration of Text-figure 98, it can 
be seen to have a certain degree of similarity with Sardimus. Both genera have a 
long narrow dermal upper jaw, and supramaxillae are absent, but Volcichthys has 
the maxilla entering the gape and bearing teeth. Possibly the two might be related 
and thus Volcichthys can be considered to have a similar origin to that already 
proposed for Sardinius. 
The basal stock of the myctophiforms, as represented by Sardinioides, was present 
at the beginning of the Upper Cretaceous and it has been shown earlier (p. 203, 
table 1) that great similarities exist between this stock and the ctenothrissiforms. 
Patterson (1967a) has shown that the ctenothrissiforms gave rise to the beryciforms 
in the Albian or thereabouts. Thus at the opening of the Upper Cretaceous both the 
myctophiforms and the beryciforms were present and increasing, whilst the cteno- 
thrissiforms were rapidly declining. Due to the incompleteness of the fossil record 
little indication can be gained concerning the time of origin of many of the recent 
myctophiform groups (Patterson, 1967b). Aulopus has already been considered in 
some detail and is little changed from its Cenomanian ancestors. A second recent 
