Ticinolepis crassidens revisited, again.

More revisions.
This is how it goes when you try to reconstruct a fish skull, like Ticinolepis crassidens, that has seen a bit of facial bone dislocation and tessalation (Fig 1).

DGS (= coloring the bones) is helpful
because it avoids freehand, avoids arrows and abbreviations, is replicable by other workers, and brings out errors if elements don’t fit they way do in tentatively related taxa. It’s a learning tool currently enjoying wider use in µCT scans.

This is what it means to ‘manipulate in Photoshop’, a practice the Wikipedia author meant to imply something other than an attempt at precision reconstruction without a pencil and paper.

Figure 2. The skull of Ticinolepis crassidens (MCSN 8072) in situ from López-Arbarello 2016, traced and reconstructed using DGS methods.

Figure 1. The skull of Ticinolepis crassidens (MCSN 8072) in situ from López-Arbarello 2016, traced and reconstructed using DGS methods. Identifying scattered skull bones is the first step. It helps to occlude the teeth with each other as a given. Then start rebuilding.

Ticinoelpis crassidens now nests far apart
from Ticinolepis longaeva (Fig 4) which lacks builbous palatine teeth and has many other distinct traits. So the two are not congeneric. I know of (= tested in the LRT) no other fish with such palatine teeth and other traits.

Figure 2. Narcetes from Fujiwara et al 2021. Compare to Prohalecites in figure 3.

Figure 2. Narcetes from Fujiwara et al 2021. This is relative of the herring, Clupea.

Ticinoelpis crassidens
(López-Arbarell, Bürgin, Furrer and Stockar 2016, PIMUZ T 273, Triassic, 240 mya) this species has large, bulbous, crushing palatine teeth. Extant Narcetes (Fig 2) from Arctic waters is relative in the LRT.

Ticinolepis longaev (Fig 4) is closer to Robustichthys.

Figure 3. This specimen, wrongly attributed to Pholidophorus, is also close to Ticinolepis crassidents and is similar in age/antiquity.

Figure 3. This specimen, wrongly attributed to Pholidophorus, is also close to Ticinolepis crassidents and is similar in age/antiquity. Still looking for a museum number on this specimen in the herring family.

Apologies for earlier mistakes on this taxon.
It takes time to get to know certain specimens and fish in general.

Figure 4. Ticinolepis longaeva shares more traits with Robustichthys.

Figure 4. Ticinolepis longaeva shares more traits with Robustichthys.

The original authors, López-Arbarello, Bürgin, Furrer and Stockar 2016,
reported, “The anatomy of this fish shows a mosaic of halecomorph and ginglymodian characters and, thus, the new taxon probably represents a basal holostean.” 

The authors did not attempt a DGS reconstruction or phylogenetic analysis

The authors concluded,
“Among them
[= more than a hundred specimens], it was not possible to identify 37 specimens beyond the generic level, but the remaining fishes were classified in two new species: T. longaeva (48 specimens) and T. crassidens (20 specimens).

Even among fish experts, It takes time to get to know certain specimens and fish in general. Please report any observable errors if corrections are warranted.

References
López-Arbarello A, Bürgin T, Furrer H and Stockar R 2016. New holostean fishes (Actinopterygii: Neopterygii) from the Middle Triassic of the Monte San Giorgio (Canton Ticino, Switzerland). PeerJ 4(e2234):1-61.

wiki/Ticinolepis

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