ESPECIALLY MYCTOPHOIDS 231 
many steps to reduce the number of moveable parts in the caudal fin. The tail is 
only required to move in one plane and it would seem that fusion of component 
parts would produce a more effective fin. In the most advanced perciforms the 
consolidation has reached an end point in which the caudal skeleton is only formed 
from one or two large plates. 
An historical review of the Ctenothrissiformes has been given by Patterson 
(1964 : 241). In this work Patterson considered three genera, Ctenothrissa, 
Aulolepis and Pateroperca, which he put into two families : 
Family Ctenothrissidae. Ctenothrissa. 
Family Aulolepidae. Avwlolepis and Pateroperca. 
In his discussion (Patterson, 1964) of the affinities of Ctenothrissa he concluded 
that “‘ Ctenothrissa is a form which has evolved towards the acanthopterygians in 
a number of characters (thoracic pelvics, no mesocoracoid, ctenoid scales, and deep 
body in particular), while still showing unmistakeable signs of an elopoid ancestry 
(small supraoccipital, foramen for orbital artery, antorbital, toothed maxilla, and 
incompletely fused vertebral elements), yet has become specialized in ways which 
exclude it from the direct ancestry of the acanthopterygians’’. However, Aulolepis 
shows several differences to Ctenothrissa, but as Patterson (1964) points out, these 
are only in degree. Pattersonichthys, like Aulolepis and Pateroperca, is more general- 
ized than Ctenothrissa and is included in the family Aulolepidae. 
One salient feature of Pattersonichthys not found in any other ctenothrissiform 
genus is the roofed post-temporal fossa. The absence of a roofed fossa excludes both 
Aulolepis and Pateroperca from the direct ancestry of the Beryciformes, since a 
partially roofed post-temporal fossa is still present in the early beryciforms (Hoplop- 
teryx, Trachichthyoides, Patterson, 1964 ; Lissoberyx, Caproberyx, Patterson, 19674). 
The presence of a roofed fossa in Pattersonichthys suggests that it is nearer to the 
direct line of ancestry of the Beryciformes than is either Ctenothrissa, Aulolepis or 
Pateroperca. 
Patterson (1967a : 106) has suggested that the ancestral beryciform stock would 
have possessed the following characteristics : 
1. Of small size with unornamented head bones. 
High supraoccipital crest from a moderately large supratemporal fossa. 
Reduced antorbital. 
Toothed maxilla. 
Scaly operculum. 
Partial roof to the post-temporal fossa. 
These characters are all present in the Ctenothrissiformes but in mosaic occurrence 
Pattersonichthys for example shows I, 3, 4 and 6 but not 2 and 5. 
The basic caudal pattern shown by the Ctenothrissiformes (Text-fig. 77) and 
Beryciformes (Patterson, 1968b) is similar to that already seen in the Myctophiformes 
(Text-fig. 72). This type of caudal skeleton was also present in several of the fossil 
salmoniform groups mentioned in this work, the Enchodontoidei (Text-fig. 42), 
Halecoidei (Text-fig. 64) and Cimolichthyoidei. 
OGL ge Se) 
