Table 1.

Morphometric comparation of Halamphorahampyeongensis with related species. ND = not documented.

	Halamphorahampyeongensis	H.atacamana	H.caribaea	H.exilis	H.montana	H.mosensis	H.specensa
Valve shape	semi-elliptical, convex dorsal and nearly straight ventral margins	semi-lanceolate, arched dorsal and straight to weakly tumid ventral margins	semi-lanceolate, convex dorsal and straight ventral margins	narrowly semi-elliptical, shallowly arched dorsal and straight ventral margins	semi-lanceolate, smoothly arched dorsal and straight to slightly convex ventral margins	narrowly semi-elliptical, smoothly arched dorsal and straight ventral margins	semi-elliptical to nearly elliptical, arched to flattened dorsal and convex ventral margins
Apices	narrowly rounded	slightly subprotracted	rostrate	narrowly rounded	broadly rounded	narrowly rounded	weakly protracted, narrowly rounded
Length (μm)	13.8–15.0	29–45	34–39	14–19	12–20	21–37	13–17
Width (μm)	2.8–3.0	4.5–8.0	6.0–8.0	2.5–3.0	3.0–4.6	4.0–4.5	3.0–3.5
Raphe	arched	arched	straight with	slightly arched	arched	arched	straight
Proximal raphe ends	slightly expanded, straight	slightly dorsally deflected	dorsally deflected	slightly dorsally deflected	slightly expanded, dorsally deflected	dorsally deflected	dorsally deflected
Dorsal striae (in 10 μm)	34–38	25–28	11–20	24–26	40–45	26–28	23–26
	bi- and uniseriate	uniseriate	ND	bi- and uniseriate	uniseriate	bi- and multiseriate	biseriate
Ventral striae (in 10 μm)	46–48	24–30	19–29	44–45	40–45	28	44–46
Habitate	brackish	brackish	marine	marine	freshwater	brackish	freshwater
References	This study (n = 31)	Levkov (2009)	Wachnicka and Gaiser (2007)	Stepanek and Kociolek (2018)	Watanabe et al. (2005); Levkov (2009)	Stepanek and Kociolek (2018)	Stepanek and Kociolek (2018)