Goodbye Sarcopterygii. Coelacanth origin and evolution according to the LRT

Wikipedia reports,
“As sarcopterygians, they are more closely related to lungfish and tetrapods (which includes amphibians, reptiles, birds and mammals) than to ray-finned fish.”

This is a traditional assumption based on the presence of lobe fins in several taxa.

Figure 1. According to the LRT, tiny Luganoia is basal to the clade Actinista (= coelacanths) distinct from traditional studies and university textbooks. According to tested taxa derived coelcanths divide themselves into giant, medium and small tadpole-liike taxa. Note the persistence of the here invisible notochord in all taxa. Once again, phylogenetic miniaturization attends the genesis of new clades. Note the tall ascending process of the premaxilla that contacts the frontals and splits the nasals.

Sarcopterygii
According to Wikipedia, “Sarcopterygii – sometimes considered synonymous with Crossopterygii – is a taxon of the bony fish known as the lobe-finned fish or sarcopterygians, characterised by prominent muscular buds (lobes) within the fins. This is in contrast to the other clade of bony fish, the Actinopterygii, which have only bony spines supporting the fins.”

This method is called, “Pulling a Larry Martin.” Never depend on a few traits to define a clade. Always use the last common ancestor method AFTER you have tested a wide gamut of taxa. Convergence is out there.

According to
the large reptile tree (LRT, 2300 taxa) coelacanths (Fig 1) arise from tiny Middle Triassic Luganoia (Fig 1), and Semionotus bergeri, ray-fin taxa with a descending tail fin axis transitional between a heterocercal morphology and that of tuft-tailed coelacanths. The lateral lobe fins of coelacanths are convergent with those of pre-tetrapod fish. No pre-tetrapods developed dorsal or anal lobe fins.

The living coelacanth, Latimeria (Fig 1) is a slow-moving, nocturnal denizen of deep waters.

Figure 2. Subset of the LRT focusing on coelacanths and their relatives. Pre-tetrapods follow Strunius and kin at the bottom of this subset.

According to Toriño, Soto and Perea 2021,
basal Actinista include Miguashaia, Styloichthys and Gavinia. These taxa remain basal to pre-tetrapod fish in the LRT, but coelcanths nest off to the side (Fig 2) with several ray-fins between the two clades. In the authors’ cladogram, Holopterygius + Allenypterus (Fig 1) are basal taxa, contra the order in the LRT (Fig 2). The authors wrote, “In this contribution, an updated phylogenetic analysis based on a new consensual data matrix is presented.”

The authors did not include Luganoia (Fig 1) in their analysis. So taxon exclusion remains the number one problem in paleontology. Let your own wide gamut analysis tell you which taxa are appropriate outgroups. Traditions perpetuate themselves when no one tests assumptions, especially widely-accepted assumptions still taught at universities.

The recent re-nesting of Dialipina
at the base of all catfish was a necessary step in this learning process. More housekeeping ahead. Many nodes are still in flux, but this one (Fig 1) seems to be well supported. All evolutionary interrelationships should be obvious once revealed through testing. Someone else should test this hypothesis with a similar taxon list.

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

References
Toriño P, Soto M and Perea D 2021. A comprehensive phylogenetic analysis of coelacanth fishes (Sarcopterygii, Actinistia) with comments on the composition of the Mawsoniidae and Latimeriidae: evaluating old and new methodological challenges and constraints. Historical Biology. 33 (12): 3423–3443.

wiki/Coelacanth
wiki/Sarcopterygii