. Bulletin of the Museum of Comparative Zoology at Harvard College. Zoology. 144 Bulletin Museum of Comparative Zoolo^.y, Vol. 150, No. 3. Figure 33. Dorsal gill arch elements and the retractor dorsalis (RAB) muscle in the stomiiform Astronesthes (dorsal view). The major muscle insertion is on the dominant fourth upper tooth plate (UP4) and fourth pharyngobranchial (PB4). (Modified from Rosen, 1973.) Other Abbreviations: E 1-4, epibranchials; PB 1^, pharyngobranchials; UP, upper pharyngeal tooth plate; UP3-F, upper pharyngeal tooth plate fused to endoskeleton. ceratobranchial five and insertio
. Bulletin of the Museum of Comparative Zoology at Harvard College. Zoology. 144 Bulletin Museum of Comparative Zoolo^.y, Vol. 150, No. 3. Figure 33. Dorsal gill arch elements and the retractor dorsalis (RAB) muscle in the stomiiform Astronesthes (dorsal view). The major muscle insertion is on the dominant fourth upper tooth plate (UP4) and fourth pharyngobranchial (PB4). (Modified from Rosen, 1973.) Other Abbreviations: E 1-4, epibranchials; PB 1^, pharyngobranchials; UP, upper pharyngeal tooth plate; UP3-F, upper pharyngeal tooth plate fused to endoskeleton. ceratobranchial five and insertion on the nrohyal, is a characteristic feature of the ctenosquamate fishes (= myctophiforms, paracanthopteiygians, and acanthopteiyg- ians; Lauder 1982a). Stiassny (in prep- aration) has found a muscle apparently homologous to the ctenosquamate phar- yngohyoideus in several aulopiforms. It is not yet clear if the aulopiforms are non- monophyletic or if this muscle has been independently ac(iuired in a few aulopi- form taxa. The pharyngohyoideus is ho- mologous to the rectus communis muscle of lower teleosts which inserts on hypo- branchial 3. The change in insertion to the uroh\al marks an important function- al shift, because the phar\ iigolnoideus is then no longer an intrinsic gill arch mus- cle, and forms the anterior element con- trolling anteroposterior and lateral move- ment of the lower phar\ ngeal jaw. Thus, the Ctenos(}uamata (Rosen, 1973) pos- sess two functionalK important pharyn- geal jaw innovations allowing greatly in- creased control of prey transport and preparation in the pharynx (Lauder, 1983). Other characters relevant to neoteleos- tean relationships are summarized in Figme 14. The Stomiiformes Although stomiiformes are considered to be the most primitixe neoteleosteans, the condition of the retractor dorsalis muscle appears to be specialized from the probable primitive condition. The sto- miiform upper pharyngeal jaw apparatus has the imcinate process of th
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