Chaenogaleus affinis ( Probst, 1878 )

Chaenogaleus affinis ( Probst, 1878)

Plate 3, Figs 1 View FIGURE 1 –12

* Galeus affinis Probst, 1878: 139 , pl. 1, figs 64–67.

Scyllium guttatum Probst, 1879: 171 , pl. 3, figs 28–29.

Eugaleus View in CoL af. minutissimus (Arambourg) — Zbyszewski & Almeida 1950: 342, pl. 7, figs 127–132.

Galeorhinus View in CoL af. lefreivei [ sic] Daimeries— Serralheiro 1954: 72, pl. 2, fig. 66.

Galeorhinus View in CoL af. minutissimus Arambourg— Serralheiro 1954: 72 ( partim), pl. 2, fig. 70 (not fig. 69).

Galeorhinus pulchellus — Jonet 1966: 80 ( partim), pl. 4, fig. 13–16.

Scyliorhinus joneti — Cappetta 1970: 45, pl. 9, figs 19–29.

Galeorhinus affinis ( Probst, 1878) — Cappetta 1970: 65, pl. 18, figs 1–18.

Galeorhinus affinis ( Probst 1878) — Antunes & Jonet 1970: 174, pl. 12, figs 75–79.

Galeorhinus affinis ( Probst 1878) — Jonet 1978:30, pl. 1, figs 6, 8–9.

Chaenogaleus affinis ( Probst, 1878) — Cappetta 1987: 118, figs 101a–f.

Chaenogaleus affinis ( Probst, 1878) —Pfeil in Barthelt et al. 1991: 202, pl. 3, fig. 7.

Chaenogaleus affinis ( Probst, 1878) — Ward & Bonavia 2001: 142, pl. 1, fig. F.

Chaenogaleus affinis ( Probst, 1878) — Reinecke et al. 2011: 57, pls. 57–60, text-figs 18–19.

Chaenogaleus affinis ( Probst, 1878) — Cappetta 2012: 295, text-figs 279a–f.

Chaenogaleus affinis ( Probst, 1878) — Schultz 2013: 89, pl. 10, figs 1a–b, 4a–b.

Chaenogaleus affinis ( Probst, 1878) —Pollerspöck & Baeury 2014: 29, pl. 2, fig. 5.

Chaenogaleus affinis Probst, 1970 [ sic]— Fialho 2015: 43, pl. 2, fig. 7, pl. 3, figs 1–3.

Chaenogaleus affinis ( Probst, 1878) — Fialho et al. 2021: 414, figs 5h–m.

Chaenogaleus affinis ( Probst, 1878) — Fialho 2022: 117, pl. 4, figs D–G.

Material. 189 isolated teeth and tooth parts. NHMW 2025 View Materials /0177/0009 ( 10 specimens) .

Description. The species is a strongly dignathic heterodont.Upper dentition( Pl. 3, figs1–7) has a parasymphyseal tooth that is wide with a high and narrow principal cusp inclining 45° distally, a slightly sigmoidal mesial cutting edge and a convex distal one. There is a coarse jagged serration of four cusplets that diminish in size of which the straight upper cutting edge is horizontal. The following series of teeth are more or less similar but with the principal cusp further inclined and an increasing number of up to seven distal cusplets. The principal cusp of the more lateral to posterior teeth diminishes in size and possesses a curved principal cusp and less distal cusplets.

The lower dentition ( Pl. 3, figs 8–12) has a series of anterior teeth with an extremely high and narrow principal cusp that is approximately four to five times as high as its base width, and a relatively narrow root that is divided into two lobes by a shallow central groove and diverged at an angle of 90°. The following teeth have a slightly lower principal cusp and the root lobes diverge at a wider angle. The principal cusp in the more lateral teeth lowers to a height of three times its base width and the root lobe become wider and diverge at an angle of 110°.

Discussion. The dentition of sharks belonging to the genera Chaenogaleus and Paragaleus (see below) is difficult to distinguish. However, the differences can be identified by referring to the work of Herman et al. (1991), which describe and depict their living representatives.

The upper dentition of Chaenogaleus presents teeth with a rather narrow, strongly distally inclined principal cusp with a sigmoidal distal cutting edge followed by a coarsely jagged serration of up to five smaller distally directed cusplets with a horizontal straight mesial cutting edge, gradually diminishing in size, the last ones often merged into a blade.

The symphyseal tooth of Paragaleus possesses an upright principal cusp flanked by one or two cusplets that are inclined approximately 30°. The following teeth possess a rather broad, strongly distally inclined principal cusp, followed by a coarse, jagged serration of up to seven distally directed smaller cusplets gradually diminishing in size, the first anterior teeth with a mesial cusplet present near the base. The mesial cutting edge of the principal cusp of anterior teeth is straight and those of the lateral teeth slightly sigmoidal.

The lower dentition of Chaenogaleus possesses anterior teeth that have an extremely high, narrow and upright principal cusp that is five to six times higher than its base width and a narrow root divided into two lobes by a rather deep central groove that diverge at an angle of approximately 45°. The principal cusp gradually lowers and becomes slightly broader whereas the root lobes become wider and strongly diverged at an angle of up to 140°. The principal cusp becomes strongly constricted resulting in largely extended smooth cutting edges. Cusplets are absent.

On the other hand, the lower dentition of Paragaleus (see below) possesses a set of anterior teeth with an upright principal that is strongly restricted near the base, resulting in a large extension of both mesial and distal cutting edges. Their root is divided into two root lobes by a deep groove that diverges at an angle of 90° in the first two anteriors and up to 140° in the following teeth. Their principal cusp becomes slightly more inclined toward the commissure and a distal cusplet arises at the lower end of the cutting edge. The lateral teeth possess a much more inclined principal cusp followed by up to three smaller cusplets that diminish in size towards the commissure.

The most significant difference between the teeth of Chaenogaleus and Paragaleus are: Upper teeth— Chaenogaleus , a narrow principal cusp and up to five distal cusplets versus a broader one and up to seven cusplets in Parageleus. Lower teeth— Chaenogaleus , extremely high, narrow and upright principal cusp becoming lower and slightly broader with the root changing from diverging from 45° to 140° versus a low principal cusp that changes from almost upright to inclined with distal cusplets in Paragaleus .

Distribution. Miocene. Lower Miocene: Paratethys ( Germany, Pollerspöck & Baeury 2014). Lower-Middle Miocene: Paratethys ( Schultz 2013). Middle-Upper Miocene: Mediterranean ( France, Cappetta 1987).

Distribution in Portugal. Lower Miocene: (Burdigalian) Lower Tagus Basin ( Zbyszewski & Almeida 1950). Middle Miocene: (Langhian-Serravallian) Lower Tagus Basin ( Zbyszewski & Almeida 1950; Antunes & Jonet 1970; Fialho 2015; Fialho et al. 2021). Upper Miocene: (Tortonian) Lower Tagus Basin ( Serralheiro 1954); Algarve Basin, Cacela Fm. (this paper).

Genus Hemipristis Agassiz, 1835

Type species. Hemipristis serra Agassiz, 1835