Finding and scoring vestigial elements in fish skulls

Someday, you too,
may need to find vestigial elements like these (Fig 1) because they can affect phylogenetic scoring. Your own cladogram and scoring matrix will alert you to their possible/probable presence, just like the LRT alerted me in this instance.

This was a eureka moment. It shed a ‘little’ light on a frustrating problem.

About now this question likely arose from your gray matter:
At what point can you ignore vestiges and mark an element or process as ‘absent’?

That’s going to be up to you and the needs of your cladogram. Play it straight.

How would you score this situation?
Are the orbits bound by a circumorbital ring? Or part of a ring? Are temporal fenestra present? Because evolution deals in transitions, sometimes the answers are not always clear. Fortunately, this sort of situation is rare.

Exocoetus volitans
(Linneaus 1758; up to 30cm ) is the extant blue flyingfish, here related to a smaller Jurassic relative, Oreochima. Exocoetus travels in schools or schoals. Sometimes they exit the water to avoid predators. Juveniles have a relatively shorter torso. Hatchlings are slow-moving and tiny. Distinctly flying fish and their relatives have a jaw joint directly below the orbit. The coracoid is larger than the scapula, raising and powering the pectoral fins.

Lampris guttatus
(Brünnich 1788; up to 2m in length) is the extant opah, a large, colorful, slow-moving discoidal fish. It was the first fish to be considered endothermic. Note the deep coracoids used to power the flapping pectoral fins. The mouth is toothless. It eats small fish and squid. Traditionally Lampris nests with the oarfish, Regalecus, but here nests closer to the flying fish, Exocoetus and the pineconefish, Monocentris.

References
Brünnich MT 1788. Om en ny fiskart, den draabeplettede pladefish, fanget ved Helsingör i Nordsöen 1786. K. Danske Selsk. Skrift. N. Saml. 3: 398-407.
Linnaeus C 1758. Systema naturæ per regna tria naturæ, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis. Tomus I. Editio decima, reformata.

wiki/Lampris
wiki/Monocentris_japonica
wiki/Oreochima
wiki/Exocoetus_volitans