With the J/M tree, where Ceratophyllum is sister to eudicots, well removed from Chloranthaceae, the most parsimonious position for Couperites is linked with Chloranthaceae, supported by its thick nexine, but attached below the crown group, because of its anatropous ovule. Positions within Chloranthaceae are at least one step less parsimonious, since they require an extra step in ovule curvature (either a reversal to anatropous or two origins of orthotropous).
The anatropous ovule, a characteristic not previously reported for the genus Syagrus had already been reported for other genera of the Tribe Cocoseae, with Attalea and Cocos (Uhl and Moore, 1971; Guevara and Jauregui, 2008).
Seed shape is described here as it is commonly illustrated with the hilum and micropyle at the 'bottom' of the seed, although it is acknowledged that this is developmentally the apex of the anatropous ovule. Acceptance of fossil determinations in this review relies first on the kind and amount of information presented by authors, then ultimately on my informed subjective judgement as to whether the paleobotanical assessments are convincing.