Lepidogalaxia, with a bendable neck, has a deep sea relative, Malacosteus, with an extremely bendable neck

Separated by time and depth
freshwater Lepidogalaxias is traditionally considered the only member of the family. Now it has a previously overlooked deep sea sister in Malacosteus after testing over 400 competing candidates in the large reptile tree (LRT, 2173 taxa).

Lepidogalaxias salamandroides (Mees 1961; McDowall RM and Pusey BJ 1983; 7cm in length) is the extant salamanderfish, the only fish with a neck capable of turning the head nearly at right angles to the torso. Like lungfish, the freshwater salamanderfish is capable of surviving dry seasons by burrowing into the sand. Note the large eyes and short rostrum. Needle-like teeth line the jaws. Derived from a basal ray fin fish Prohalecites, molecular studies consistently recover Lepidogalaxias close to the base of the Telostei where it also nests in the LRT.

This appears to be a novel hypothesis of interrelationships.
If not, please send a citation so I can promote it here.

References
Ayres WO 1848. pp. 64–73. In: Proceedings of the Boston Society of Natural History, Vol. 3. Proceedings of the Boston Society of Natural History, Boston.
Ayres WO 1849. Description of a new genus of fishes, Malacosteus. Boston Journal of Natural History 6:53–64.
Kenaley CP 2007. Revision of the Stoplight Loosejaw Genus Malacosteus (Teleostei: Stomiidae: Malacosteinae), with Description of a New Species from the Temperate Southern Hemisphere and Indian Ocean. Copeia. 2007 (4): 886–900. doi:10.1643/0045-8511(2007)7[886:
McDowall RM and Pusey BJ 1983. Lepidogalaxias salamandroides Mees — A redescription, with natural history notes. Rec. West. Aust. Mus. 11(1):11–23.
Mees GF 1961. Description of a new fish of the family Galaxiidae from Western Australia. J. Roy. Soc. West. Aust. 44: 33-38.

wiki/Lepidogalaxias
wiki/Malacosteus