202 UPPER CRETACEOUS TELEOSTS 
Order MYCTOPHIFORMES 
The ordinal ranking given to this group is based on the fact that it can be separated 
from the Salmoniformes and the Ctenothrissiformes at least by the opening of the 
Upper Cretaceous. This is in agreement with the ordinal rank given by Gosline, 
Marshall and Mead (1966 : 5) although, as these authors point out, there is apparently 
no one feature that will separate all myctophiforms from all salmoniforms. Green- 
wood, ef al. (1966 : 366), using the same criterion, that they could find no diagnostic 
characters which would satisfactorily distinguish these forms from those they group 
as the Salmoniformes, therefore consider the Myctophiformes to be merely a suborder 
within the order Salmoniformes. This ordinal separation will be considered in 
greater detail further on in this discussion. 
The term Myctophiformes is considered preferable to the alternatives previously 
used, Iniomi and Scopeliformes, since the group has normally been collectively 
termed the myctophoids. 
A re-evaluation of Woodward’s (1901 : 235) family Scopelidae, in particular the 
Cretaceous genera, has shown that several of these do not belong in the Myctophi- 
formes. 
Sedenhorstia (Microcoelia) White and Moy-Thomas (1941) and Dactylopogon von 
der Marck (1858) are both elopiforms (Goody, 1969). 
Ichthyotringa (Rhinellus) Cope (1878), and Apateodus Woodward (1901), are both 
primitive salmoniforms (see pp. 169 to 176). 
The remaining Cretaceous genera are more nearly referable to the myctophiforms: 
Sardinioides von der Marck (1858), Cassandra (Leptosomus) White and Moy-Thomas 
(1940), Acrognathus Agassiz (1843), Nematonotus Woodward (1901), and Sardinius 
von der Marck (1858). 
Sardimoides is indisputably a myctophiform and Cassandra would appear to be 
synonymous with it. The species of Sardinioides considered in the systematic 
account (Sardinioides minimus) was originally described as Cassandra minima. 
This species represents a form very close to the ancestral myctophiform stock. 
Sardinioides is a genus which has received some attention in the past as being a form 
from which both the present day Myctophiformes and also possibly the Acantho- 
pterygii could have been derived. Patterson (1964) considered the latter possibility 
and examined both Sardinioides and Aulopus as possible acanthopterygian ancestors. 
He concluded that they were not on the direct line of descent of the acantho- 
pterygians, but that this ancestry was closer to the Ctenothrissiformes. 
A table is given below of the major osteological characters shown by the Sal- 
monoidei (the most primitive group within the Salmoniformes) as illustrated by 
Salmo and the corresponding characters of the Myctophiformes (from Sardiniotdes) 
and the Ctenothrissiformes (from Pattersonichthys). Similarity to Salmo is indicated 
by a cross (xX). 
