Monday, February 24, 2020

[PaleoIchthyology • 2020] Thiollierepycnodus wagneri • A New Genus of Pycnodontidae (Actinopterygii) from the Upper Jurassic of France and Germany, included in A Phylogeny of Pycnodontiformes

Thiollierepycnodus wagneri (Thiollière, 1852)

in Ebert, 2020.

The new genus Thiollierepycnodus is erected here to accommodate ‘Gyroduswagneri or ‘Proscineteswagneri, a taxon known since the 19th century from the marine Kimmeridgian Plattenkalk of Cerin (France) and since 2014 at the excavation site of the Naturkunde-Museum Bamberg in Wattendorf (Germany). Thiollierepycnodus is placed in Pycnodontidae (Upper Jurassic to Eocene), which is the most advanced family of Pycnodontiformes. With 154–152 Myr (Upper Jurassic), Thiollierepycnodus belongs to the stratigraphically oldest Pycnodontidae, still possessing some primitive features such as four incisiform teeth in the dentary, a crown of bifurcated anterior dentary teeth, reduced scale bars posterior to the dorsal fin origin, but the area of pterygiophores without scales and nine to 10 postanal ventral keel scales and approximately 10 complete scale rows posterior to the cloaca. A phylogenetic analysis leads to the placement of this taxon in Proscinetinae. This and the introduction of two additional taxa from the Cretaceous of Lebanon in the phylogeny are further steps to enlighten the broader evolutionary patterns of Pycnodontidae.

Keywords: evolution, fossil fish, Kimmeridgian, Proscinetinae

Figure 4. Cranium of Thiollierepycnodus wagneri from Cerin, France.
A, photograph of specimen (MHNL20015207). B, camera lucida drawing of (MHNL20015207). C, photograph of specimen (MHNL20015202). D, camera lucida drawing of (MHNL20015202). Due to reasons of space, the heads are rotated from their ‘normal’ position (approximately 20 degrees in Fig. 4A, B and approximately 40 degrees in Fig. 4C, D).

Figure 2. Thiollierepycnodus wagneri holotype (MHNL20015207) from Cerin, France.

Systematic palaeontology 

Actinopterygii Cope, 1872 
Neopterygii Regan, 1923 
Pycnodontiformes Berg, 1937 (sensu Nursall, 2010)

Pycnodontoidei Nursall, 1996 (sensu Poyato-Ariza & Wenz, 2002) 
Pycnodontoidea Agassiz, 1833 (sensu Poyato-Ariza & Wenz, 2002) 
Pycnodontidae Agassiz, 1833 (sensu Nursall, 1996) 
Proscinetinae Poyato-Ariza & Wenz, 2002

Thiollierepycnodus Ebert, gen. nov. 

Etymology: The genus epithet refers to Victor Joseph de l’Isle Thiollière (1801–1859) who first recognized and described the species, plus the suffix pycnodus because Thiollière first assigned this species to the genus Pycnodus.

Thiollierepycnodus wagneri (Thiollière, 1852), comb. nov. 

Pycnodus wagneri Thiollière, 1852: Thiollière, 1853: pl. 7, fig. 1; Thiollière, 1854: 23; Thiollière, 1873: 12. 
Microdon wagneri (Thiollière, 1852): Heckel, 1856: 201; Wagner, 1860: 396; Zittel, 1887: 247, fig. 258; Woodward, 1895: 225; Eastman, 1914: 368, pl. 53, figs 1, 2. 
Gyrodus wagneri (Thiollière, 1852): Saint-Seine, 1949: 127, pl. 13, fig. B, pl. 14, fig. B. 
Proscinetes? wagneri (Thiollière, 1852): Poyato-Ariza & Wenz, 2002: 151.

Distribution: All specimens above are from the Plattenkalk of Cerin, France, except the specimen from the NKMB, which is from Wattendorf, Bavaria, Germany. 

Etymology: The specific epithet in Thiollierepycnodus wagneri refers to Dr Johannes Andreas Wagner 1797– 1861, who was professor of zoology at the university in Munich and conservator of the Zoologische Staatssammlung München, Germany. 

Type locality: Cerin, Ain, France. 

Type horizon: Upper Kimmeridgian up to the eigeltingense horizon of the Tithonian (lowest horizon of the Tithonian).

Figure 7. Caudal fin of Thiollierepycnodus wagneri from Cerin, France. A, (MHNL20015214). B, (MHNL20015204).

Martin Ebert. 2020. A New Genus of Pycnodontidae (Actinopterygii) from the Upper Jurassic of France and Germany, included in A Phylogeny of Pycnodontiformes. Zoological Journal of the Linnean Society. 188(2); 434–454. DOI: 10.1093/zoolinnean/zlz087