The deep-sea gulper eel (Eurypharynx) also arises from rhizodontid lobefins

Earlier we resurrected an ‘extinct’ clade of rhizodont lobefin fish,
when the moray eel, Gymnothorax (Fig. 2) entered the large reptile tree (LRT, 1518 taxa) along with the the rhizodont, Barameda. Today the deep sea gulper eel, Eurypharynx (Figs. 1,2), nests with Gymnothorax. 

Eurypharynx pelecanoides (= Gastrostomus Vailiant 1882; up to 75cm long) is the extant deep sea pelican eel or gulper eel. Like its sister, the moray eel (Gymnothorax, Fig. 2), the naris, antorbital fenestra, orbit and temporal fenestra are confluent. Pectoral fins are barely present. Distinctly the jaw joint is far behind the occiput and hyperelongated hyomandibular and quadrate. The stomach can stretch to accomodate large prey. The muscle segments are V-shaped, not W-shaped, as in most bony fish. The lateral line system projects from the body, rather than lying in a groove.

This appears to be a novel hypothesis of interrelationships.
If someone else has published on this earlier, please let me know so I can cite them properly.

The YouTube video (above)
shows the slender, oversized jaws can balloon with water AND the dorsal half above the skull does, too! This is done, evidently, as a threat display, to appear much larger than ordinary, and to feed, convergent with the blue whale (Balaenoptera) and other rorqual mysticetes.

References
Bloch ME 1795. Naturgeschichte der ausländischen Fische. Berlin. v. 9. i-ii + 1-192, Pls. 397-429.
Valliant LL 1882. Sur un poisson des grandes profondeurs de l’Atlantique, l’Eurypharynx pelecanoides. Comptes Rendus Hebdomadaires des Séances de l’Académie des Sciences, Série D, Sciences Naturelles 95: 1226-1228.

wiki/Gogonasus
wiki/Onychodus
wiki/moray eel
wiki/Barameda
wiki/Rhizodus
wiki/Eurypharynx