Re-study of Guangdedendron micrum from the Late Devonian Xinhang forest

Table 1 Comparisons of Guangdedendron micrum, Minostrobus chaohuensis, Changxingia longifolia, Changxingia sp., Sublepidodendron songziense and Sublepidodendron grabaui

	G. micrum [15]		M. chaohuensis [18, 23]	C. longifolia [24]	Changxingia sp. [25]	S. songziense [17, 20, 21]	S. grabaui [19, 22]
Branching system	Dichotomize at least twice		Dichotomize at least eight times	Dichotomize at least twice	–	Monocaulous trunk with dichotomized lateral branches	Dichotomize at least four times with lateral branches
Shape of leaf cushion	–	Narrow-fusiform	Narrow-fusiform	Rhomboid	Rhomboid	–	–
Shape of leaf base	Narrow-fusiform		Rhombic	Oblanceolate	Rhomboidal	Fusiform, narrow-rhomboid or oval	Narrow-fusiform
Strobili known	Megasporangiate		Mega- and microsporangiate	Megasporangiate	Mega- and microsporangiate	Mega- and microsporangiate	Mega- and microsporangiate
Attachment of terminal strobilus(i)	Singly or in pairs	Singly, in pairs or occasionally once-dichotomized	Singly	Singly	–	Singly	Singly
Megaspore number per megasporangium	–	Multiple	4, sometimes unequal in sizes	Probable 4	Over 4?	At least 20	–
Megaspore type	–	Lagenicula	Lagenicula	Lagenicula	Lagenicula	Lagenicula	–

–, lack of information; the data in the left and right columns of G. micrum are from Wang et al. [15] and this study, respectively

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