Glossanodon GUICHENOT , 1867

Přikryl, Tomáš, 2013, An Annotated List Of The Oligocene Fish Fauna From The Osíčko Locality (Menilitic Fm.; Moravia, The Czech Republic), Acta Musei Nationalis Pragae Series B 69 (3 - 4), pp. 195-203 : 198-200

Genus Glossanodon GUICHENOT, 1867

“ Glossanodon ” musceli ( PAUCĂ, 1929)

Text-fig. 3

1929 Nemachilus musceli ; Paucă, p. 114.

1934 Nemachilus musceli PAUCĂ ; Paucă, p. 598, pl. 2, figs 1–2.

1958 Nemachilus Musceli PAUCA ; Jonet, p. 44, pl. 5, fig. 7.

1967 Glossanodon musceli (PAUCĂ) ; Jerzmańska, p. 200, text-figs 2, 4, 6, 8, 10, pl. 1, figs 1–2.

1968 Glossanodon musceli (PAUCĂ) ; Jerzmańska, p. 394.

1974 Glossanodon musceli (PAUCĂ) ; Kalabis and Schultz, p. 187, pl. 1, fig. 2.

1977 Glossanodon musceli (PAUCĂ) ; Ciobanu, p. 65, pl. 15, fig. 1.

2003 Glossanodon musceli (PAUCA) ; Gregorová and Požár, p. 196, photo 4.

non 2005a Austromalotus musceli (PAUCĂ) ; Prokofiev, p. 10, figs 4–6.

2011 Glossanodon musceli (PAUCĂ) ; Gregorová, p. 8, pl. 3, fig. 1.

M a t e r i a l: NM Pc 02870a, b – Pc 02875a, b, Pc 02877a, b; collected from the Dynów Mb.

R e m a r k s: The collected specimens are rather fragmentary, with a long slender body and maximal body depth close behind the head. It is possible to recognized ca. 47 vertebrae (22+25). The fin rays are insufficiently preserved and their numbers are not clearly discernable. The pectoral fin is totally unreadable. The dorsal fin is situated in the middle of the body length (with ca. 10 rays); the ventral fin (with more than seven rays) is shifted slightly anteriorly. Although the anal fin is not completely preserved in any of the specimens, the caudal peduncle in specimen Pc 02780a appears to be formed by 6–7 vertebrae (judging by the last preserved anal fin ray). The skull bones are crushed and therefore, hardly readable (it is however possible to identify some of them, or their general positions; see text-figs 3C-2 and 3D). The fragmentary caudal skeleton (text-figs 3B–1, 2) was tentatively reconstructed (text-fig. 3B–3).

The specimens were traditionally classified as Glossanodon musceli ( Argentinidae ), but Prokofiev (2005a) revised Caucasian and Turkmenistan Protacanthopterygii on the basis of important morphological features which have been overlooked for many years. His results showed that his specimens pertain to the family Osmeridae (rather than to the Argentinidae ) and were thus placed in the new genus Austromallotus .

Material from the Osíčko locality cannot be similarly classified mainly due to the unsatisfactory preservation. The important morphological features, such as (1) presence of the notch on the dorsal edge of the operculare, (2) transformation of the neural spines on the anterior abdominal vertebrae (significant shortening is not present in all specimens, or it is not clearly visible), and (3) arrangement of 1 st and 2 nd infraorbitals (if they are in contact or not) are not recognizable, or they were destroyed or are different from those described by Prokofiev (2005a). Furthermore, the studied specimens show a longer caudal peduncle (6–7 vertebrae) and slightly different morphology of the caudal skeleton than in A. musceli (according to Prokofiev 2005a: fig. 6c). Thus it is impossible to unify both forms and the specimens described herein are classified traditionally as members of the genus “ Glossanodon ”. A higher taxonomical position of the taxon is uncertain due to the lack of clarity regarding construction of the circumorbital series.

The species (sensu Paucă, 1929) is distributed in many Moravian localities, such as Litenčice, Kelč, Špičky, Nikolčice, Mouchnice, Rožnov pod Radhoštěm and others ( Kalabis and Schultz 1974, Kalabis 1975a, b, Gregorová 1988, 2011, Gregorová and Požár 2003).

As was mentioned above, the construction of the circumorbital series is unclear and thus also any concrete higher taxonomic position. Consequently it is difficult to estimate the bathymetric demands of these specimens. If we take into account the original classification (i.e., Argentinidae ) these are found at a depth of 1000 m, but adults are commonly taken from the margin of the continental shelves ( Weitzman 1997).

Figures

Text-fig. 3. “Glossanodon” musceli A – nearly complete specimen NM Pc 02875a; B – caudal skeleton of specimens NM Pc 02871b and NM Pc 02871a (B-1 and B-2 respectively; part and counterpart) and its tentative reconstruction (B-3); C – specimen NM Pc 02873a, general view (C-1) and detail of the head (C-2); D – specimen NM Pc 02874a (the white arrow shows normally developed neural spine on the anterior abdominal vertebra). Abbreviations: ao – antorbitale; d – dentale; epu – epurale; fr – frontale; hp1-6 – hypurals 1-6; io – infraorbitals; mx – maxillare; npu2 – neural spine of second preural vertebra; ph – parhypurale; pu1 – first preural vertebra; pop – preoperculum; psp – parasphenoideum; stu – stegurale; u1 – urale 1; u2 – urale 2.