Pseudoasterophyllites cretaceusfrom the Cenomanian (Cretaceous) of the Czech Republic: A possible link between Chloranthaceae andCeratophyllum

Abstract

Pseudoasterophyllites cretaceus from the Cenomanian of Bohemia was recently recognized as an angiosperm by association with stamens containing monosulcate pollen of the Tucanopollis type. New material indicates that the stamens were borne in short spikes, with each stamen subtended by a bract, whereas the carpels were solitary and contained a single pendent, orthotropous ovule. We have investigated the phylogenetic position of Pseudoasterophyllites by including it in a morphological analysis of extant angiosperms using backbone constraint trees that represent the current range of hypotheses on relationships of the five mesangiosperm clades. With a backbone tree in which Chloranthaceae are linked with magnoliids and Ceratophyllum with eudicots, the most parsimonious position of Pseudoasterophyllites is sister to Chloranthaceae, but a sister-group relationship to Ceratophyllum is only one step less parsimonious. With a backbone tree in which Chloranthaceae and Ceratophyllum form a clade, Pseudoasterophyllites is sister to Ceratophyllum, based on derived features shared with both Chloranthaceae and Ceratophyllum plus solitary female flowers (as in Ceratophyllum). Similar results are obtained when Pseudoasterophyllites is added to the analysis with other fossils inferred to be related to Chloranthaceae and/or Ceratophyllum. If the plants that produced Tucanopollis pollen in the Barremian-Aptian of Africa-South America are related to Pseudoasterophyllites, these results suggest that Chloranthaceae and Ceratophyllum are relicts of one of the most important early radiations of angiosperms, which included not only colonizers of disturbed terrestrial habitats but also halophytes and aquatics.

How deep is the conflict between molecular and fossil evidence on the age of angiosperms?

“…An intriguing case is the continuous‐tectate genus Tucanopollis , from the Barremian–Aptian of Brazil (Regali, ) and Gabon/Congo (Doyle et al ., ; Doyle & Hotton, ) and the Hauterivian–Barremian of England (Hughes, ). It is similar to pollen of the Cenomanian genus Pseudoasterophyllites , a presumed halophyte with reduced leaves, which has been linked with Ceratophyllum and Chloranthaceae on molecular trees in which these taxa form a clade (Kvaček et al ., ). The floating aquatic Montsechia , from the Barremian of Spain, has also been associated with Ceratophyllum (Gomez et al ., ), but its pollen is unknown.…”

Early Cenomanian palynofloras and inferred resiniferous forests and vegetation types in Charentes (southwestern France)

“…According to Lidgard and Crane (1990) which has been recorded in macrofloral assemblages from Charentes and Bohemia (Kvaček et al, 2012(Kvaček et al, , 2016, would be an early representative of the family with halophytic adaptations, unknown in modern Chloranthaceae.…”

Evidence for an extinct lineage of angiosperms from the Early Cretaceous of Patagonia and implications for the early radiation of flowering plants

“…The placement of Mesodescolea within the angiosperms was tested using the matrix of Kvaček et al . (2016), trimmed to include only leaf characters and updated by addition of seven new characters (orders of reticulate venation, shape of tertiary vein areas, freely ending veinlets, intramarginal or fimbrial vein, Zone I‐type stomatal variation, T‐pieces and intrusive epidermal oil cells) and rescoring of a few taxa (for further details see Notes S1). We employed Maximum Parsimony (MP) and Bayesian Inference (BI) to place Mesodescolea on three backbone trees, which differ in the arrangement of the five mesangiosperm clades.…”

“…Many terminal taxa in the Kvaček et al . (2016) dataset are families, scored based on phylogenetic inference of ancestral states. This risks overlooking relationships to taxa nested within the families.…”