Taxonomic revision of Coscinodiscus variabilis (Bacillariophyta): analysis of type material, lectotypification and transfer to the genus Actinocyclus Author Lameiro, Rubén A. División Ficología, Facultad de Ciencias Naturales y Museo, Universidad Nacional de La Plata. Paseo del Bosque s / n, B 1900 FWA, La Plata, Argentina & Centro de Investigaciones y Transferencia Golfo San Jorge, UNPSJB - CONICET, Ruta Provincial 1, Km 4, 9000, Comodoro Rivadavia, Argentina Author Cefarelli, Adrián O. Centro de Investigaciones y Transferencia Golfo San Jorge, UNPSJB - CONICET, Ruta Provincial 1, Km 4, 9000, Comodoro Rivadavia, Argentina & Instituto de Desarrollo Costero, Universidad Nacional de la Patagonia San Juan Bosco. Ruta Provincial 1, Km 4, 9000, Comodoro Rivadavia, Argentina Author Vouilloud, Amelia A. 0000-0002-9709-5127 División Ficología, Facultad de Ciencias Naturales y Museo, Universidad Nacional de La Plata. Paseo del Bosque s / n, B 1900 FWA, La Plata, Argentina & avouilloud @ fcnym. unlp. edu. ar; https: // orcid. org / 0000 - 0002 - 9709 - 5127 avouilloud@fcnym.unlp.edu.ar text Phytotaxa 2023 2023-11-28 626 4 269 278 https://phytotaxa.mapress.com/pt/article/download/phytotaxa.626.4.4/51319 journal article 279794 10.11646/phytotaxa.626.4.4 2b8bdf47-bd2f-4378-b208-5fd82ba2198f 1179-3163 10212960

TABLE 1. Comparison of Actinocyclus ferrarioae (Frenguelli) Lameiro, Vouilloud & Cefarelli nom. nov. with allied taxa.

Taxa	Valve	Nº of	RP in	Areolae	Striae in 10	Valve	Hyaline rays length	Fasciculation	Environment	References
*Measured on the figures in the publications
	Diameter	Fascicles	100 µm	in 10 µm	µm	face features		pattern
	(µm)
Actinocyclus	39–57	6–7	4.1–7*	5–6*	8 (center)	Flat with convex	Long (cosmiodiscoid);	Parallel*	Marine	Frenguelli (1928)
ferrarioae					12 (margins)	edges	not so defined		Recent	as Coscinodiscus
Lameiro, Vouilloud							(actinocycloid)			variabilis
& Cefarelli	29–59	6–14	4.8–8.2	8–10	8–10 (center)	Flat o almost	Complete, incomplete	Parallel		This study
	(44.1)				8–12 (v.	flat; with central	(¾ to ⅓ of the valve
					margin)	depressions,	face), not clearly
						curving towards	defined
						the mantle
A. asteriscus	20–75	3–4 to 16	3.6–4.9*	7–10	18–19	Dome-shaped	Complete*	Parallel	Marine	Wu et al.
(Barron) Wu,				(center)					Fossil	(2022)
Williams, Pheng &				9–13
Cheng				(margin)
A. kanitzii	50–100	13–15*	10.4–	7–9	14*	Flat	Incomplete (¾ to ⅓ of	Radial	Lacustrine	Bradbury & Krebs
(Pantocsek			11.1*				the valve face)*		Fossil	(1995)
& Grunow)
Schauderna
A. ingens var.	40–86	10*	7*	3–6	6*(valve	Flat with central	Incomplete (half of the	Parallel	Marine	Desikachary &
indica Desikachary					center)	depression and	valve face)*		Extant	Prema (1987)
& Prema					10*(valve	rounded margins*
					margin)
A. nipponicus	15–73	6 to 20	5.7–8.3*	10–12	14–18*	Almost entirely	Complete, incomplete	Radial–Subparallel–	Lacustrine	Hayashi et al.
Hayashi, Saito-						flat with inclined	(¾ to ⅓ of the valve	Parallel (according	Fossil	(2012)
Kato & Tanimura						mantle	face), not clearly	to valve size)
							defined*
A. nigriniae Barron	15–70	3–15	7–8.75*	8 (center)	11–12*	Flat or domed	Incomplete	Parallel	Marine	Barron
				12			(¾ to ⅓ of the valve		Fossil	(2005)
				(margin)			face)*
A. podolicus	35–57	11*	5.8–	15–17	14–16*	Flat with slightly	Incomplete (¾ of the	Parallel	Brackish-	Ognjanova &
(Missuna)			11.9*			raised center	valve face)*		Marine	Buczko
Koryzenko									Fossil	(2015)
A. claviolus	17–60	6–8*	6.4–7.3*	13–14	20*	nearly flat with	Not clearly defined *	Radial and	Lacustrine	Bradbury & Krebs
Bradbury & Krebs	(27–30)					raised or depressed		Subparallel	Fossil	(1995)
						center
A. tenellus	56–70	8–9*	3.6–4.5*	6	18	Nearly flat	Not clearly defined*	Parallel	Marine	Andrews
(Brèbisson)									Fossil	(1976)
Andrews