Table 2 in Revision of Eocene electric rays (Torpediniformes, Batomorphii) from the Bolca Konservat-Lagerst atte, Italy, reveals the first fossil embryo in situ in marine batoids and provides new insights into the origin of trophic novelties in coral reef fishes

Table 2. Summary of selected meristic features used to discriminate fossil and living genera of the family Narcinidae. Includes new data from the examined material and data from Fechhelm & McEachran (1984), Rincon (1997), Carvalho et al. (1999, 2002a, b, 2003), Carvalho (2001, 2008), Rincon et al. (2001), Carvalho & Śeret (2002), Carvalho & Randall (2003), Menni et al. (2008), Carvalho & White (2016), Last et al. (2016), Froese & Pauly (2017).
FeatureBenthobatisDiplobatisDiscopygeNarcine† TitanonarkeTrunk vertebrae13–2023–252015–3127–30Precaudal vertebrae46–7361–6358–7058–7774–115Caudal vertebrae31–4622–24?18–3223–32Total vertebrae96–11897–11285–91100–127133–155Rib pairs47–985–108–10Total pectoral radials?31?27–4135–40Pelvic fin radials12–1316–21?14–2119–21First dorsal fin radials5–66–7?6–107–9Second dorsal fin radials6–77–8?6–116–7Total caudal fin radials34–3533–36?39–6341–42Upper jaw tooth rows9–2014–2210–2011–2712–13Lower jaw tooth rows9–2214–2210–208–3015–17