The silver sweep (Scorpis) enters the LRT basal to flatfish

No new heresies to report here.
Scorpis is widely considered basal to flatfish (= halibut, flounder and sole; Friedman 2008). As reported earlier with piranha, I needed to add a taxon to the large reptile tree (LRT, 1709+ taxa; Fig. x) to clarify issues, and flounders needed a non-flounder at their base. Not surprisingly, this gambit worked!

Figure 2. Scorpis skull from Gregory 1938. Colors added here. No asymmetry is present on this outgroup to the flatfish.

Figure 1. Scorpis skull from Gregory 1938. Colors added here. No asymmetry is present on this proximal outgroup to the flatfish.

Scorpis lineolata (Kner 1865; 30cm) is the extant silver sweep or false pompano. This deep, but narrow oceanic fish has a mouthful of sharp teeth, a deep lacrimal and a tall post parietal (= ‘soc’ here). This denizen of Australian waters feeds on plankton over rock reefs. Distinct from related taxa, the postfrontal (orange in Fig. 1) contacts the prefrontal (brown in Fig. 1).

Figure 2. Flatfish evolution from Scorpis to Psettodes and Cynoglossus.

Figure 2. Flatfish evolution from Scorpis to Psettodes and Cynoglossus.

The evolution of flatfish
(Fig. 2) finds Scorpis at the base and swimming upright with symmetrical left and right eyes.

When flatfish evolve to hug the sea floor
and bury themselves in loose sand note the forward progress of the pelvic fin and the rotation of the eyes to the top side.

Note the loss of teeth
in the basal flatfish, Heteronectes, followed by a taxon with extra long teeth in Psettodes.

Figure x. Subset of the LRT, focusing on fish for July 2020.

Figure x. Subset of the LRT, focusing on fish for July 2020.

According to the heretical LRT,
Scorpis was derived from the mackeral, Scomber. Sister taxa include the perch (Perca) and its descendants. Beyond that clade comes the threadfin (Polydactylus) and its descendants.

On a somewhat separate note:
Several paleontologists (most recently Nick Gardiner on Facebook) have noticed that homologous bones in fish, classic reptiles and mammals sometimes do not share the same name. This can stop immediately if biologists and paleontologists want that to happen. Just give all the bones the names found in reptiles. No more circumorbital series. No more zygoma. Now just call the cheekbone the jugal. Or at least use matching (= homologous) colors. At present the jugal is traditionally a bright cyan (Fig, 1). The benefits to such a change are self-evident.


References
Friedman M 2008. The evolutionary origin of flatfish asymmetry. Nature 454:209–212.
Kner R 1865. Reise Novara, Fische, 1865: 108, Sydney.

http://reptileevolution.com/hippoglossus.htm
wiki/Silver_sweep

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