Fruit structure in Magnoliaceae s.l. and Archaeanthus and their relationships

Abstract

The specializations of dehiscent multifollicles of unknown Cretaceous ancestors for different modes of seed and fruitlet dispersal formed the basis for the differentiation of two evolutionary lines with their divergence occurring more than 100 million years ago: Magnoliaceae s.s. and the Archaeanthus-Liriodendroidea-Liriodendron line (Liriodendraceae s.l.) within the order Magnoliales.

Recognising angiosperm clades in the Early Cretaceous fossil record

“…The analysis of Doyle and Endress (2010) strongly associated Archaeanthus with Magnoliaceae, either attached to the stem lineage of the family or nested within it, linked with one or the other of its two subgroups (Liriodendron and Magnolioideae ¼ Magnolia s.l.). A recent analysis by Romanov and Dilcher (2013) placed Archaeanthus in the crown group of Magnoliaceae, as the sister group of Liriodendron. However, this analysis treated lobation of the leaf apex and the leaf blade as two characters, when they represent only one change from the ancestral unlobed leaf, and it incorrectly identified the whorled perianth phyllotaxis of Archaeanthus and Liriodendron as a synapomorphy because it used the distantly related genus Illicium (Austrobaileyales) as outgroup rather than other Magnoliales, most of which also have a whorled perianth (Massoni et al in press).…”

Fossil calibration of Magnoliidae, an ancient lineage of angiosperms

“…The clade of Archaeanthus and Magnoliaceae was supported by three unambiguous synapomorphies: sheathing leaf base, bilobed stipules, and elongate receptacle, while the positions within the family were supported by bilobed leaf apex (shared with Liriodendron) or dehiscent fruit (shared with Magnolioideae). By contrast, a recent cladistic analysis by Romanov and Dilcher (2013) positioned Archaeanthus sister to the Late Cretaceous seed genus Liriodendroidea (Frumin and Friis, 1996) and identified the clade made up of these two extinct genera as the sister group of Liriodendron, supported by four synapomorphies. This would imply that Archaeanthus provides a minimum age for crown-group Magnoliaceae.…”

“…The status of the fourth synapomorphy, fruitlets shed from the receptacle, is uncertain, since Degeneria and most Annonaceae also have this feature (van Setten and Koek-Noorman, 1992). These observations imply that there are no more acceptable synapomorphies of Archaeanthus and Liriodendron in the Romanov and Dilcher (2013) data set than in Doyle and Endress (2010).…”

“…in Doyle and Endress, 2010) argued that it is more likely latest Albian, based on a carbon isotope and sequence stratigraphic study by Gröcke et al (2006) at the Rose Creek locality in Nebraska, where a flora described by Upchurch and Dilcher (1990) lies just below the Albian-Cenomanian boundary, plus the fact that the Dakota is transgressive toward the east and sites such as Russell County are among its most western exposures. A latest Albian age was accepted by Doyle and Endress (2010) and reaffirmed without discussion by Romanov and Dilcher (2013). However, although the Rose Creek and Linnenberger Ranch floras were both assigned to the Jansen Clay Member and considered roughly coeval by Farley and Dilcher (1986), their equivalence needs reexamination in light of detailed sequence stratigraphic and palynological analyses of the Dakota Formation in Kansas, Nebraska, and Iowa by Ludvigson et al (2010).…”

Magnolia llanganatensis (Subsect. Talauma , Magnoliaceae), una especie nueva de Tungurahua y clave para las especies de Magnolia de Ecuador

“…La subfamilia Magnolioideae Arn. diverge de Liriodendroideae Y.W.Law hace más de 100 millones de años (Romanov y Dilcher, 2013). La familia incluye 350 especies en el mundo, casi la mitad de ellas del Continente Americano (Vázquez- García et al, en prensa); sin embargo, no hay consenso sobre su número de secciones (0-11), géneros (1-13), subgéneros (0-9) o subfamilias (0-2) (Figlar y Nooteboom, 2004;Nianhe et al, 2008, Romanov y Dilcher, 2013) y a pesar de varios estudios filogenéticos de Magnoliaceae en las últimas dos décadas, su clasificación sigue siendo controvertida (Qiu et al, 1993(Qiu et al, , 1995aKim et al, 2001;Azuma et al, 2001, Li y Conran, 2003Nie et al, 2008;Kim y Suh, 2013).…”