The flying gurnard and sea robin enter the LRT

Updated January 26, 2020
with the realization that the laterally exposed face plates of these two fish are the lacrimal, jugal and postorbital that are lacking in a wide range of sister taxa. These changes shifted their phylogenetic nesting to between the jack (Seriola sonata) and the frogfish (Antennarius).

Updated again April 24, 2021
with a new nesting of Dactylopterus alongside the basal ray fin fish, Calamopterus, apart from the convergently similar sea robin Prionotus.

Strange fish!
Dactylopterus volitans (Linneaus 1758; 50 cm) is the extant flying gurnard, a bottom-feeder living in warm shallow seas. Tradtionally Dactylopterus is allied with long-snouted pipefish and seahorses. Here it nests with the basal ray fin fish, Calamopterus,

Dactylopterus volitans (Linneaus 1758; 50 cm) is the extant flying gurnard, a bottom-feeder living in warm shallow seas. Typically Dactylopterus is allied with long-snouted pipefish and seahorses. Here it nests much earlier, with Calamopterus (above). Note the remnant of the heterocerval tail (above), a primitive trait. Like its sister, the skull has a wide and slightly concave box shape. The mouth is horizontal. The nares are vertical on the anterior corners of the skull. Distinct from its sister, the teeth are tiny to absent.

When startled the butterfly-like pectoral fins spread wide as the undulating tail pushes the fish away from danger. The tabulars are quite large and extend like a dorsal shield. The pelvic fins are below the giant pectoral fins, convergent with more derived fish. The anterior pectoral fin spines are separate from the large fan and are more mobile, like sea robin (Prionotus) ‘fingers’, but webbed.

Figure 1. Dactylopterus skull with colors added to match tetrapod taxa.

Figure 1. Dactylopterus skull with colors added to match tetrapod taxa.

Prionotus evolans (Linneaus 1766; 40cm; Fig. 2) is the extant striped sea robin, a scorpionfish that uses a set of finger-like flexible spines of its large pectoral fin to walk on the seafloor. With a long straight snout, it looks more like it’s barracuda-like ancestors, but nests with its sister, the short-snouted flying gurnard, Dactylopterus (above).

Figure 2. Prionotus, the sea robin, has more of a barracuda-like face. Uniquely, medial spines from the pectoral fin evolve to act like fingers for walking on the sea floor.

Figure 2. Prionotus, the sea robin, has more of a barracuda-like face. Uniquely, medial spines from the pectoral fin evolve to act like fingers for walking on the sea floor.

These additions and several revisions
to the large reptile tree (LRT, 1643+ taxa then, 1838+ taxa now) continue this nine-year online project. This hypothesis of interrelationships appears novel. If previously published, let me know so I can promote that citation.


References
Linnaeus C von 1758. Systema naturæ per regna tria naturæ, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis. Tomus I. Editio decima, reformata.
Linneaus C von 1766. Systema naturæ per regna tria naturæ, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis. Tomus I. Editio duodecima, reformata. pp. 1–532. Holmiæ. (Salvius)

wiki/Flying_gurnard
wiki/Triglidae (sea robins)
wiki/Prionotus_carolinus (northern sea robin)

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