Lepidogalaxias

Williams, R. R. G., 1997, Bones and muscles of the suspensorium in the galaxioids and Lepidogalaxias salamandroides (Teleostei: Osmeriformes) and their phylogenetic significance, Records of the Australian Museum 49 (2), pp. 139-166 : 155-157

Lepidogalaxias +Galaxiidae + Aplochitonidae

(8B) Lateral foramen for hyomandibular branch of facial nerve at ventral end of lateral strut of hyomandibular (see synapomorphy 8 for details). A lateral strut is absent in Lovettia .

(13) Mesopterygoidal teeth reduced in number or absent ( Fig. 13: BA). These teeth are also absent in esocoids, salmonids, salangids, alepocephalids, and the Argentinoidea, and are few in platytroctids. Primitively in galaxioids ( Retropinnidae + Prototroctidae ) and osmerids the entire medioventral surface of the mesopterygoid bears numerous teeth ( Williams, 1987).

galaxiids Galaxias paucispondylus (Williarns, 1987) , Galaxiella pusilla and G. nigrostriata ( Frankenberg, 1969) . Furthermore, the metapterygoid does not contact the symplectic and just barely contacts the hyomandibular in Aplochiton taeniatus (Fig. 6), and contacts neither the symplectic nor the hyomandibular in A. zebra ( McDowall, 1969, fig. 3).

Aplochitonidae the maxillo-mandibular ligament extends from the anterolateral end of section A2 to the maxilla. However, the part of the maxillo-mandibular ligament attaching onto the lower jaw is unlike the outgroups. The section extending to the angulo-articular ( Figs 9- 12 : L.y) is reduced so there is almost no separate segment (Fig. 14: L.z) extending from the adductor mandibulae to the main part (L.x-L.y) of the maxillomandibular ligament. The maxillo-mandibular ligament also has a new section ( Figs 9-12 : L.w) extending anteroventrally from the intersection of L.x and L.y to the coronoid process (dentary).

(16) Tendinous aponeurosis on which medial fibres of section A2 ofadductor mandibulae insert not connected

with posteriormost end of maxilla-mandibular ligament or barely connected with it (shared with the argentinoid Bathylagus ). The state in Lovettia could not be determined mainly because of small specimen size. Primitively, there is a distinct connection between the anterodorsal edge of the tendinous aponeurosis (before it bifurcates anteriorly) and the posteriormost end of the maxillo-mandibular ligament.

Figures

Fig. 10. Galaxias maculatus (UAMZ 4609, 92.6 mm): (A) lateral view of external muscles of left suspensorium; (B) ventrolateral (slightly posterior) view of tendons/ligaments attaching section A2 of adductor mandibulae onto maxilla and lower jaw, anterolateral fibres of section A2 inserting onto tendons/ligaments are removed. Ligament L (see Fig. 9) is not drawn.

Fig. 11. Galaxias Jasciatus (UAMZ 5122, 95.2 mm): (A) lateral view of external muscles of left suspensorium; (B) ventrolateral (slightly posterior) view of tendons/ligaments attaching section A2 of adductor mandibulae onto maxilla and lower jaw, anterolateral fibres of section A2 inserting onto tendons/ligaments are removed. Ligament L (see Fig. 9) is not drawn.

Fig. 12. Lateral view of external muscles of left suspensorium III 104.1 mm). Ligament L (see Fig. 9) is not drawn.