Thrissops subovatus Münster

Ebert, Martin, 2025, New species of the genus Thrissops (Teleostei, Ichthyodectiformes) in the Upper Jurassic of the Solnhofen-Archipelago (Germany) and Kimmeridge Clay (England), Zitteliana 99, pp. 1-32 : 1-32

Thrissops subovatus Münster in Agassiz, 1843

Figs 6 , 18 C , 20 D

1843 Thrissops subovatus Münster in Agassiz: p. 128.

1863 Thrissops subovatus Münster in Agassiz; Wagner: p. 734.

1895 Thrissops formosus Agassiz ; Woodward: p. 521 (partim NHMUK PV P. 920, P. 3678, P. 3683 a).

1914 b Thrissops formosus Agassiz ; Eastman: p. 423 (partim, CM 4030), pl. 72, fig. 2.

1964 Thrissops subovatus Münster in Agassiz; Nybelin: p. 10; pl. 3, fig. 1, 2, pl. 4, fig. 1; pl. 5, figs 1–3.

1965 Thrissops subovatus Münster in Agassiz; Bardack: p. 33.

1968 Thrissops subovatus Münster in Agassiz; Leich: fig. on p. 112.

1977 Thrissops subovatus Münster in Agassiz; Taverne: figs 3, 7.

1994 Thrissops subovatus Münster in Agassiz; Frickhinger: figs 495, 496.

2008 Thrissops subovatus Münster in Agassiz; Taverne: figs 1, 9.

2013 Thrissops subovatus Münster in Agassiz; Ebert and Kölbl-Ebert: p. 45; fig. 3, 5; tab. 1.

2020 Thrissops subovatus Münster in Agassiz; Kölbl-Ebert and Ebert: fig. 15 b.

2021 Thrissops subovatus Münster in Agassiz; Ebert: p. 38; fig. 6 C, tabs 1, 2.

2024 Thrissops subovatus Münster in Agassiz; Alvarado-Ortega: fig. 16.

2024 Thrissops subovatus Münster in Agassiz; Ebert: p. 355; figs 12.12 A – C, 12.15, 13.8; tab. 12.1.

Holotype.

SNSB - BSPG AS VII 178 ( Ebert 2021, fig. 6 C) .

Type Locality.

Kelheim (most probably Kapfelberg) , Bavaria, Germany.

Type horizon.

Upper Kimmeridgian.

Determination.

Standard length (SL) to body depth (BD) specimens 26–29 % (average 28 %); Maximum length 43 cm; 59–60 vertebrae (without ural centra); 38–40 supraneurals; 30–31 abdominal ribs; 30–31 anal pterygiophores; lager, bigger and less numerous teeth than other Thrissops species (except for Th. cirinensis ); dentary teeth of irregular size; ventral margin of maxilla more straightened than in the other Ichthyodectiformes ; vertebral axis in front of the caudal fin first bends slightly downwards before turning into the upper caudal lobe.

Distribution and frequency.

Only known from the Solnhofen Archipelago, Bavaria, Germany, but rare in all localities (see Fig. 21 and Suppl. material 1: table S 1).

Additional specimens.

CM 4030 (“ Solnhofen ”); Coll. Leich Bochum (Eichstätt without number); Coll. Tischlinger 01 / 26 (Öchselberg), 98 / 23 (Eichstätt); DMA (Painten without number); JME -ETT 2639 , 3465 (both Ettling); JME -SOS 2525 (Solnhofen), 4253 (Wintershof, Eichstätt Basin); LF 1469 (Eichstätt); MB. f. 15887 (Kelheim); MBH 20253251, 20253252 (both Blumenberg, Eichstätt Basin); MMG-SNSD BaJ 2115 (Eichstätt); NHMUK PV P. 920, P. 3678, P. 3683 a (all three Kelheim); NMP UC 2280 (Solnhofen); NMS 1905.83. 12 (Kelheim); ROMVP 947 (Solnhofen); SMNS - P- 86700 (Zandt).

Figures

Figure 6. Thrissops subovatus from the lower Tithonian of Ettling, Markt Pförring, Bavaria, Germany. A. JME - ETT 3465 a, b; B. JME - ETT 2639.

Figure 18. Jaws and dentition of Thrissops from the Solnhofen Archipelago, Bavaria, Germany. A. Th. formosus (JME - ETT 1805) from Ettling; B. Th. formosus (JME - ETT 887) from Ettling; C. Th. subovatus (LF 1469) form Eichstätt; D. Th. ettlingensis (JME - ETT 3345 a) from Ettling.

Figure 20. Maxilla shape of different Upper Jurassic Thrissops species. A. Th. formosus (JME - ETT 1805) from Ettling; B. Th. formosus (JME - ETT 887) from Ettling; C. Th. subovatus (LF 1469) form Eichstätt; D. Th. ettlingensis (JME - ETT 3345 a) from Ettling.

Figure 21. Pathologies in Thrissops formosus von Ettling, Bavaria, Germany. A. Pathological caudal fin of JME - ETT 2750; B. Two pairs of ribs on one vertebra in JME - ETT 74.