Early Cretaceous floral structures and<i>in situ</i>tricolpate‐striate pollen: New early eudicots from Portugal

Pedersen, Kaj Raunsgaard; Balthazar, Maria von; Crane, Peter R.; Friis, Else Marie

doi:10.1080/00173130701526507

Cited by 33 publications

(19 citation statements)

References 48 publications

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“…Herbs occur in several 'basal' eudicot lineages (e.g. Ranunculales, Proteales, Buxales), and the handful of putative eudicot mesofossils and megafossils [17][18][19] described from Aptian-mid Albian deposits appear herbaceous (electronic supplementary material, S1). Further, angiosperm wood is exceedingly rare in the Lower Cretaceous despite abundant gymnosperm wood in the same deposits [20,21].…”

Section: Introductionmentioning

confidence: 99%

Fossil evidence for a herbaceous diversification of early eudicot angiosperms during the Early Cretaceous

Jud¹

2015

Proc. R. Soc. B.

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Eudicot flowering plants comprise roughly 70% of land plant species diversity today, but their early evolution is not well understood. Fossil evidence has been largely restricted to their distinctive tricolpate pollen grains and this has limited our understanding of the ecological strategies that characterized their primary radiation. I describe megafossils of an Early Cretaceous eudicot from the Potomac Group in Maryland and Virginia, USA that are complete enough to allow reconstruction of important life-history traits. I draw on quantitative and qualitative analysis of functional traits, phylogenetic analysis and sedimentological evidence to reconstruct the biology of this extinct species. These plants were small and locally rare but widespread, fast-growing herbs. They had complex leaves and they were colonizers of bright, wet, disturbance-prone habitats. Other early eudicot megafossils appear to be herbaceous rather than woody, suggesting that this habit was characteristic of their primary radiation. A mostly herbaceous initial diversification of eudicots could simultaneously explain the heretofore sparse megafossil record as well as their rapid diversification during the Early Cretaceous because the angiosperm capacity for fast reproduction and fast evolution is best expressed in herbs.

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Section: Introductionmentioning

confidence: 99%

Fossil evidence for a herbaceous diversification of early eudicot angiosperms during the Early Cretaceous

Jud¹

2015

Proc. R. Soc. B.

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“…late early Albian, rather than either late Aptian or early Albian (as assumed by Friis et al 2006Friis et al , 2011: ca. 15% of the angiosperm taxa are tricolpate, some of them striate (Pedersen et al 2007). The rich Torres Vedras locality (Friis et al 2010) is perceptibly older, but rather than being Barremian-early Aptian (Friis et al 2006(Friis et al , 2010(Friis et al , 2011, it may be near upper Zone I in age, since it contains Pennipollis, indicative of a post-Barremian age (reviewed in Doyle & Endress 2014), plus C. rotundus-like monosulcates (Friis et al 2010, pl.…”

Section: Summary Of Stratigraphic Resultsmentioning

confidence: 99%

“…However, in the upper part of the lower Albian these are joined by striate tricolpates, which are not known in Zone I. Similar pollen is known in flowers (probably Buxales) from some Portuguese mesofossil localities (Pedersen et al 2007). It should be noted that these are not the oldest striate tricolpates globally; such pollen is known from the Aptian of Brazil (Heimhofer & Hochuli 2010), Gabon Doyle 1992) and Egypt (Penny 1988b), in the Northern Gondwana province of Brenner (1976).…”

Section: Background On the Potomac And Portuguese Sequencesmentioning

confidence: 99%

Early Cretaceous (Albian) spores and pollen from the Glen Rose Formation of Texas and their significance for correlation of the Potomac Group

Tanrikulu¹,

Doyle

Delusina

2017

Palynology

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Because the Gulf Coast Lower Cretaceous is dated by ammonites, it has great potential as a reference section for correlating continental sequences such as the Potomac Group and dating events in the rise of angiosperms. Middle Albian terrestrial palynofloras from Oklahoma have been described in detail, but the early Albian interval, represented in the Glen Rose Formation of Texas, is less well known. Samples from two localities on the Paluxy River, which correlate with horizons containing late early Albian ammonites, are dominated by Classopollis and Exesipollenites, but angiosperm pollen is the next most common terrestrial element, and there are several index spore species for Zone II in the Potomac Group. Among the angiosperms, reticulate monosulcates are most common and diverse, but there are also several tricolpate species. Stratigraphically important angiosperms include the Clavatipollenites rotundus group and reticulate tricolpates, which appear in the upper part of Potomac Zone I and the dated earliest Albian of England and Portugal. However, there are also tricolpates with striate-reticulate sculpture, a pollen type that is not known from upper Zone I but appears in the late early Albian of Portugal. This assemblage contrasts with floras from Potomac Zone II and the middle Albian (lower Fredericksburg Group) of Oklahoma, where tricolpates overtook monosulcate angiosperms in species diversity. These results confirm arguments based on the Portuguese section that there is a significant hiatus between Potomac Zones I and II, and that this gap is at least partly late early Albian. The dominance of Classopollis and Exesipollenites and the occurrence of isolated Northern Gondwanan elements (Sergipea, Tucanopollis) suggest that Texas lay in a transition zone between Southern Laurasia and the hotter and drier Northern Gondwana province, but regional studies are needed to disentangle geographic and climatic factors from effects of the lagoonal local environment.

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“…The mesofossil floras studied so far range from the late Barremianearly Aptian to the late Aptian-early Albian. Most assemblages are dominated by angiosperms, and studies have mainly focused on the angiospermous component of these mesofossil assemblages (Friis et al, 1994(Friis et al, , 1997(Friis et al, , 1999(Friis et al, , 2000(Friis et al, , 2001Pedersen et al, 2007). However, reproductive organs of extinct gymnospermous plants have also been identified in the Portuguese Cretaceous floras, and it is clear that some of these gymnosperms also played an important role in the vegetation, particularly during the Early Cretaceous (Friis & Pedersen, 1996;Rydin et al, 2004Rydin et al, , 2006Friis et al, 2007;Friis et al, submitted;Mendes et al, 2008).…”

mentioning

confidence: 94%

Raunsgaardispermum lusitanicumgen. et sp. nov., a new seed within situpollen from the Early Cretaceous (probably Berriasian) of Portugal: Further support for the Bennettitales‐Erdtmanithecales‐Gnetales link

Mendes

Pais

Friis

2008

Grana

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A new genus and species, Raunsgaardispermum lusitanicum, is described from the Bombarral formation, Early Cretaceous (probably Berriasian) of Portugal. The new taxon is based on small well-preserved, lignitised seeds, about 1.2 -2.1 mm long and 0.9 -1.26 mm wide, ovoid to broadly elliptic in outline with a distinct pointed micropylar region. The seed wall is composed by a thin membranous integument extended apically into a long tubular micropyle. The integument is enclosed almost completely by an outer envelope except for a small circular opening for micropylar region. The outer envelope is bivalved and sclerenchymatous, ornamented by narrow longitudinal ridges. Papillae are present apically on the inner surface of the seed envelope adjacent to the micropylar tube. Monocolpate, tectate-psilate-punctate pollen grains, about 26 -29 mm long and 14 -16 mm wide, were observed in situ in the micropyle of one seed and on the outer surface of several others. The seeds show an interesting character combination of distinct ephedroid seed characters coupled with pollen characters of Bennettitales and Erdtmanithecales and add further evidence to the link between Bennettitales, Erdtmanithecales and Gnetales.

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Early Cretaceous floral structures andin situtricolpate‐striate pollen: New early eudicots from Portugal

Cited by 33 publications

References 48 publications

Fossil evidence for a herbaceous diversification of early eudicot angiosperms during the Early Cretaceous

Fossil evidence for a herbaceous diversification of early eudicot angiosperms during the Early Cretaceous

Early Cretaceous (Albian) spores and pollen from the Glen Rose Formation of Texas and their significance for correlation of the Potomac Group

Raunsgaardispermum lusitanicumgen. et sp. nov., a new seed within situpollen from the Early Cretaceous (probably Berriasian) of Portugal: Further support for the Bennettitales‐Erdtmanithecales‐Gnetales link

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