COHEN: GADIFORMES 



263 



RECENT. 



PLEISTOCENE. 



PLIOCENE. 



MIOCENE. 



OLIGOCENE. 



EOCENE. 



PALEOCENE. 



"PROTOCODUS" 



Fig. 136. Phylogenetic bush showing hypothetical inter-relationships among gadirorm fishes. Beginning of soHd Unes based on fossils, not 

 including otoliths or scales. 



V-shaped indge on the frontals and also lateral flanges on the 

 rear of the skull that characterize gadines and at least some 

 morids. They write, "The skull roof of Rhinocephalns shows 

 many features common to morids, merlucciids, gadids. and 

 macrourids . . . ." In addition, the first neural spine is free from 

 the supraoccipital crest. 



Eucltchthys (Fig. 137), represented by a single South Austra- 

 lian and New Zealand species, was incorrectly placed in Moridae 

 but removed by Svetovidov (1969), who pointed out some sim- 

 ilarities to Macrouridae. Enclichlhys can not be placed in any 

 currently recognized family. It has a free first neural spine, which 

 may indicate an origin prior to Palaeogadus. lacks an otophysic 

 connection, has four hypurals nearly fused to two, and in two 

 specimens has only one of the X-Y bones. As in morids, which 

 are more specialized than macrourids and could not have given 

 rise to them, Eitclichthys has an asymmetrical, rather reduced 

 caudal fin. Perhaps this curious fish is a modem representative 

 of a macrourid progenitor. 



Macrouroidinae is represented by two small genera and has 

 been treated both as a subfamily of Macrouridae (Marshall, 

 1973) and a separate family (Okamura, 1970a). It has single 

 dorsal and anal fins and a number of distinctive features in the 

 head skeleton and may represent the most primitive tail-less 

 macruroid. 



Macrourinae-Trachyrincinae, which may well constitute two 



quite separate groups, has 20-25 genera and contains more than 

 half of all gadiform species (Okamura, 1970a; Marshall, 1973). 

 The caudal fin is absent in most, vestigial in a few; the first 

 neural spine is free, and there is no V-shaped ridge. Eggs of the 

 few species for which information is available have a distinctive 

 hexagonal pattern; many species have light organs. 



Bathygadinae, with two genera, differs from other macrourids 

 in having a large, terminal mouth, dorsal rays longer than anal 

 ones, and in a variety of other ways summarized by Okamura 

 (1970a), who interprets most of the bathygadine characters as 

 primitive ones. Differences in functional morphology between 

 bathygadines as pelagic feeders and macrourines as benthic to 

 benthopelagic feeders have been described by McLellan (1977). 



Melanonus has two meso-to-bathypelagic species formerly 

 placed in Moridae, where they do not belong as they lack an 

 otophysic connection, have a single dorsal fin, and have lost the 

 X-Y bones. Otherwise, they seem similar to Moridae. The first 

 neural spine is joined to the occipital crest, suggesting an origin 

 after Rhinocephalus. A separate family was proposed by Mar- 

 shall (1965). 



Moridae consists of 12-15 genera, some highly diverse, and 

 all characterized by possession of an otophysic connection, 4 or 

 5 hypurals, X-Y bones, a joined first neural spine, and distinctive 

 otoliths; many species have light organs. Morids probably di- 

 verged from the main Rhinocephalus-Palaeogadus-Merluccius 



