Allolepidotus ruppelii ( Bellotti, 1857 )

López-Arbarello, Adriana & Brocke, Rainer, 2024, New generic name for a small Triassic ray-finned fish from Perledo (Italy), Swiss Journal of Palaeontology (30) 143 (1), pp. 1-12 : 2-3

Species Allolepidotus ruppelii ( Bellotti, 1857)

1857 Pholidophorus ruppelii nob.—Bellotti: p. 428.

1886 Pholidophorus Rüppeli Bell. —Bassani: p. 63.

1889 Allolepidotus Rüppelli Bell. sp. —Deecke: p. 117– 118, pl. 6: Fig. 5 .

1910 Allolepidotus Rüppelli Bell. sp. —De Alessandri, p. 118–120, pl. 8: Fig. 4 .

2001 Pholidophorus rueppelli —Lombardo: p. 350.

Lectotype

SMF P.1266 ( Fig. 1 ), plaster copy described by Bellotti (1857).

Diagnosis

Although there is little anatomical information preserved in the lectotype, the following combination of features distinguishes the species: BD/SL = 0.31; HL/SL = 0.24; HL/BD = 0.79; PreV/SL = 0.48; PreD/SL = 0.60; PreA/ SL = 0.69; (PreD-PreV)/SL = 0.11; (PreA-PreD)/SL = 0.10; 37 scales along the lateral line; posterior border of scales serrated. Pterygial formula: (D20 / V8 A19 C32) T37.

Remarks According to Te Code (ICZN Art. 32.5), the original spelling of the species Pholidophorus ruppelii is correct and posterior emendations are unjustified.

Bellotti (1857) named this species for two specimens. Te whereabouts of one of them are unknown. Te other specimen, which he described, was represented in a plaster copy at the MSNM, which is currently housed in the SMF collection, and is designated here as the lectotype .

Detailed examination of SMF P.1266 does not allow for confirmation of the values given by Bellotti for the numbers of rays and fulcra in the fins. Te peculiar shape of the dorsal fin might be an artifact due to incomplete preservation of the original fossil or imperfect replication in the plaster copy. However, the few general features preserved in SMF P.1266 such as the body proportions and relative position of the fins are sufficient to validate the species.

It should be noted that Deecke’s description of this species is not based on the cast, but on another specimen that has not been located. Nevertheless, according to the description of this unknown specimen, it is likely that it is a different species than SMF P.1266.

Figures

Fig. 5 Relative position of the fins respect to the body length in the studied taxa. Scatter plots of the ratios reflecting the position of the dorsal and anal fins relative to the standard length (a), and the position of the dorsal and pelvic fins relative to the standard length (b). The numbers accompanying the symbols correspond to the standard length values of each specimen

Fig. 4 Dorsal (a), anal (b, left) and pelvic (b, right) fins of Perledovatus nothosomoides (Deecke, 1889). b.fu basal fulcra, fr.fu fringing fulcra

Fig. 1 Allolepidotus ruppelii (Bellotti, 1857). Photograph of the lectotype SMF P.1266, a plaster copy described by Bellotti (1857)