Squatina subserrata ( Münster, 1846 ), , 1846

Squatina subserrata ( Münster, 1846)

Plate 6, Figs 1–8 View FIGURE 1 View FIGURE 2 View FIGURE 3 View FIGURE 4 View FIGURE 5 View FIGURE 6 View FIGURE 7 View FIGURE 8

* Sphyrna subserrata Münster 1846: 21 , pl. 2, fig. 17.

Scaldia biforis Le Hon 1871 : pl. 7 text-fig.

Squatina fraasi Probst 1879: 177 , pl. 3, figs 37, 38.

Squatina View in CoL alata Probst 1879: 177, pl. 3, figs 41, 42.

Squatina biforis (Le Hon, 1879) — Leriche 1926: 382, pl. 26, figs 1–4.

Rhina ( Squatina) biformis [ sic] Le Hon— Serralheiro 1954: 74, pl. 2, figs 72, 73.

Rhina ( Squatina) crassa Daimeries— Serralheiro 1954: 74 , pl. 2, fig. 74.

Rhina ( Squatina) prima Winkler— Serralheiro 1954: 75 , pl. 2, figs 75, 76.

Squatina subserrata ( Münster, 1846) — Antunes & Jonet 1970: 212, pl. 17, fig. 132.

Squatina subserrata Münster, 1846 [ sic]— Cappetta 1970: 77, pl. 8, figs 8–14.

Squatina subserrata (Munster [ sic], 1846)— Jonet 1978: 35, pl. 2, fig. 32.

Squatina subserrata (Münster), 1846 [ sic]— Balbino 1995: 44, pl. 3, figs 2–5.

Squatina subserrata ( Münster, 1846) — Cappetta 2012: 146, text-fig. 134.

Squatina subserrata ( Münster, 1846) — Schultz 2013: 33, pl. 4, figs 14a–c.

Squatina subserrata Munster, 1846 [ sic]— Fialho 2015: 22, pl. 1, fig. 2.

Squatina subserrata ( Münster, 1846) — Fialho et al. 2021: 5, figs 3h, i.

Squatina subserrata ( Münster, 1846) — Fialho 2022: 99, pl. 1, figs E, F.

Material. 23 isolated teeth. NHMW 2025 View Materials /0177/0018 ( 9 specimens) .

Description. The dentition of an extant successor Squatina africana Regan, 1908 was illustrated by Bass et al (1975b: 50, pl. 9) that is used to identify the fossil remains. Generally, there is a slight dignathic heterodonty present by upper teeth with a narrow principal cusp that is broader in lower teeth. The first tooth (Pl. 6, figs 1a, b) is an anterior tooth characterised by a mesio-distally narrow width. The slightly inclined principal cusp is relatively high and restricted just above its base resulting in smooth mesial and distal extensions. The base of the principal cusp has a well-developed central uvula. The hemiaulacorhizid root has two root lobes that diverge at an angle of approximately 100° support the extensions of the principal cusp. A central lingual protrusion has the characteristic foramen of a hemiaulacorhizid root type. The lateral teeth (Pl. 6, figs 2a–3b) become significantly wider, with wider root lobes, and have a straight base that diverge at an angle of 160–180°. The posterior teeth have root lobes that diverge at an angle of 110°. Although a broader principal cusp, the lower teeth (Pl. 6, figs 5a–8b) are more or less similar to those of the upper teeth.

Discussion. The extant species of this genus are bottom-dwelling and are epipelagic to mesopelagic ( 0–600 m deep, Ebert et al. (2016). We assume that the Miocene predecessors also probably shared the same habitats.

Distribution. Lower–Middle Miocene: Paratethys ( Schultz 2013); Proto-Mediterranean, France ( Cappetta 1970).

Distribution in Portugal. Middle Miocene: (Langhian–Serravallian) Lower Tagus Basin ( Serralheiro 1954; Antunes & Jonet 1970; Jonet et al. 1975; Fialho et al. 2021), Algarve Basin, Lagos–Portimão Fm. ( Antunes et al. 1981). Upper Miocene: (Tortonian) Lower Tagus Basin ( Serralheiro 1954; Jonet 1978), Algarve Basin, Cacela Fm. (this paper); (Messinian) Alvalade Basin, Esbarrondadoiro Fm. ( Balbino 1995).