Otodus megalodon ( Agassiz, 1835 )

Hovestadt, Dirk C. & Da Silva, Carlos M., 2025, A new chondrichthyan (Sharks and Rays) Fossil Assemblage from the Miocene Cacela Fm. at Albufeira (Algarve, Portugal) with two new species: Palaeoecology and Biogeography, Zootaxa 5724 (1), pp. 1-66 : 11

Otodus megalodon ( Agassiz, 1835)

Plate 1, Figs 3–4

* Carcharodon megalodon Agassiz 1835 : pl. 29, figs 1–2, 5.

Carcharodon megalodon Agassiz, 1843 [ sic]— Leriche 1926: 412, pl. 35, figs 1–6, pl. 36, figs 1–5, text-figs 187–190.

Carcharodon megalodon Charlesworth, 1837 — Van de Geyn 1937: 278, 315, pl. 1–2, pl. 11, figs 9–12.

Carcharodon megalodon (Charlesworth) — Zbyszewski & Almeida 1950: 322, pl. 4, figs 60–69, pl. 5, figs 72, 76–78.

Carcharodon megalodon (Charlesworth) var. chubutensis Ameghino, 1901 — Zbyszewski & Almeida 1950: 327, pl. 3, fig. 59, pl. 5, figs 70–71, 73–75, pl. 6, figs 115–119.

Carcharodon megalodon Agassiz, 1843 — Kruckow 1960: 57, text-figs 4a, b, pl. 4, fig. a.

Procarcharodon megalodon ( Agassiz, 1843) — Kruckow 1964: 59, 62, text-fig. 10.

Procarcharodon megalodon (Agassiz) — Jonet et al. 1975: 203, pl. 1, fig. 2.

Carcharodon megalodon Agassiz, 1843 — De Ceuster 1976: 135, pl. 5, figs 6–10; 7, fig. 12.

Carcharodon megalodon Agassiz, 1843 — Menzel 1979: 106, pl. 10, fig. 1.

Procarcharodon megalodon Agassiz [ sic]— Antunes et al. 1981: 17, pl. 2, fig. 15.

Carcharocles megalodon ( Agassiz, 1843) — Nolf 1986: pl. 56, figs 1–6.

Carcharocles megalodon Agassiz, 1843 [ sic]— Balbino 1995: 59, pl. 7, fig. 2.

Carcharocles megalodon Agassiz, 1843 [ sic]— Müller 1999: 40, pl. 4, figs 8, 10.

Carcharodon megalodon Agassiz, 1835 — Purdy et al. 2001: 131–137, figs 37–42.

Carcharocles megalodon ( Agassiz, 1843) — Antunes & Balbino 2003: 144, pl. 4, fig. 2.

Carcharocles megalodon Agassiz, 1835 — Reinecke et al. 2011: 42, pl. 42, figs 1a–6c.

Otodus ( Mechaselachus) megalodon ( Agassiz, 1835) — Cappetta 2012: 227, figs 210a–f.

Megaselachus megalodon (Agassiz in Charlesworth, 1837 [ sic])— Ávila et al., 2012: 180, fig. 7.

Megaselachus megalodon ( Agassiz, 1835) — Schultz 2013: 70, pl. 6, figs 1a, b–6a, b.

Otodus ( Megaselachus) megalodon Agassiz, 1843 [ sic]— Fialho 2015: 29, pl. 1, fig. 7.

Megaselachus megalodon (Agassiz in Charlesworth, 1837)— Antunes et al. 2015: 182, figs 1–4.

Otodus megalodon ( Agassiz, 1843) — Boessenecker et al. 2019: 8, figs 2–8, 10.

Otodus ( Megaselachus) megalodon ( Agassiz, 1835) — Fialho et al. 2021: 6, pl. 3, figs l, m.

Otodus ( Megaselachus) megalodon ( Agassiz, 1835) — Fialho 2022: 104, pl. 2, fig. A.

Material. Two isolated teeth. NHMW 2025/0177/0035 (2).

Description. The first tooth ( Pl. 1, fig. 3) is an anterior tooth with a principal cusp possessing slightly concave mesial and distal cutting edges. The root is severely damaged. The second tooth ( Pl. 1, fig. 4) belongs to the lateroposterior group with a distally inclined principal cusp and concave mesial and distal cutting edges. The root has two root lobes that diverge at an angle of 110°.

Discussion. The generic/subgeneric taxonomic status of this species has been the subject of much debate, most recently, e.g., by Long et al. (2014), who placed it in Carcharocles , and Boessenecker et al. (2019), who placed it in Otodus . Some authors also assigned the species to a subgenus within Otodus . In this work we avoid the use of subgenera and consider this species to belong to Otodus at full genus rank.

Distribution. Miocene to Pliocene, Eastern and western Atlantic, Mediterranean, Indian and West Pacific Oceans ( Müller 1999). Possibly surviving into the Pleistocene ( Cappetta 1987). For more detailed information on distribution see Schultz (2013) and Boessenecker et al. (2019).

Distribution in Portugal. Lower Miocene: (Burdigalian) Lower Tagus Basin (Zbyszewski 1940; Zbyszewski & Almeida 1950; Serralheiro 1954). Middle Miocene: (Langhian-Serravallian), Lower Tagus Basin ( Zbyszewski & Almeida 1950; Serralheiro 1954; Jonet 1964; Antunes & Jonet 1970; Jonet et al. 1975; Fialho 2015; Fialho et al. 2021); (Serravallian) Algarve Basin, Lagos–Portimão Fm., ( Zbyszewski & Almeida 1950; Antunes et al. 1981). Upper Miocene: (Tortonian) Lower Tagus Basin ( Zbyszewski & Almeida 1950), Algarve Basin, Cacela Fm. (this paper); (Messinian), Alvalade Basin, Esbarrondadoiro Fm. ( Balbino 1995; Antunes & Balbino 2003). Lower Pliocene: Santa Maria Island, Azores ( Ávila et al. 2012).

Figures

FIGURE 3. Fossil shark and ray teeth on the surface of the fine sand bed at the sampling site at Leixão dos Alhos, Oura region, Albufeira municipality, Algarve, Southern Portugal (see Fig. 2). 1—Carcharhinus cf. brevipinna; 2—Myliobatiformes indet.; 3—Carcharias cuspidatus; Pb—Very rounded mainly quartz pebbles.

FIGURE 4. Taxa identified in the search sample assemblage with their absolute and relative abundances within the sample. Taxa in bold, together, represent 66.9% of the assemblage. Specimens in the search sample: 2260. Total number of specimens examined (search + bulk sample): 2579.