comment on this calibration
Magnoliineae
| node name Magnoliineae Look for this name in NCBI Wikipedia Animal Diversity Web | ||
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recommended citations http://palaeo-electronica.org/content/fc-2 Massoni et al. 2015 |
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node minimum age 112.6 Ma The fossil considered here was collected from the Crato Formation in the Araripe sedimentary basin of northeastern Brazil (Mohr et al., 2013). Mohr and Bernardes-de-Oliveira (2004) assumed that the Crato Formation is late Aptian or early Albian in age, based on numerous previous estimates (e.g., Pons et al., 1996). Because of this uncertainty, Clarke et al. (2011) proposed a minimum age for the Crato of 98.7 Ma, the top of the Albian. However, evidence has been accumulating in favor of a late Aptian age (Coimbra et al., 2002). Most recently, using gymnosperm pollen and dinoflagellates to correlate with better-dated sections, Heimhofer and Hochuli (2010) concluded that the Aptian-Albian boundary lies above the Crato Formation, and this was accepted by Mohr et al. (2013). We therefore propose a minimum age of 112.6 Ma for Endressinia, the Aptian-Albian boundary (113 ±0.4 Ma; Ogg and Hinnov, 2012). | ||
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node maximum age 0 Ma none specified | ||
| primary fossil used to date this node | ||
MB.PB 2001/1455 | ||
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phylogenetic justification
A molecular scaffold analysis by Doyle and Endress (2010), including 64 extant taxa sampled across angiosperms and 142 morphological characters, placed Endressinia in seven different most parsimonious positions: all positions within the crown group of the clade Himantandraceae + Degeneriaceae + Eupomatiaceae + Annonaceae (each represented as one terminal), or as the sister group of this clade. These relationships were supported by one unequivocal synapomorphy, the presence of glands on the stamens or staminodes (Doyle and Endress, 2010). A more recent molecular scaffold analysis (Mohr et al., 2013), which used a modified version of the morphological data set of Doyle and Endress (2010) reduced to Magnoliales, Laurales, and Canellales (as outgroup), placed Endressinia as the sister group of Schenkeriphyllum glanduliferum (another fossil from the same deposit, discussed below), with the clade of the two fossils being the sister group of Magnoliaceae. Endressinia and Schenkeriphyllum were united by sessile leaf blade (a new character) and linked with Magnoliaceae by sheathing leaf base and dry fruit wall. As noted by Mohr et al. (2013), Doyle and Endress (2010) did not score Endressinia as having a sheathing leaf base. This was probably because the sheath was formed from the unusual sessile leaf blade, rather than a leaf base separated from the blade by a petiole, but this difference does not rule out homology of the character. We have not attempted to resolve this conflict with a new analysis. The implications for dating are complicated by the fact that the position of Magnoliaceae within Magnoliales is still debated. Two alternative positions have been supported by most analyses: either as the sister group of a clade of Degeneriaceae + Himantandraceae (Soltis et al., 1999, 2007; Qiu et al., 2000, 2005, 2006; Savolainen et al., 2000; Zanis et al., 2002, 2003), or sister to a clade of Degeneriaceae + Himantandraceae + Eupomatiaceae + Annonaceae (Doyle and Endress, 2000; Sauquet et al., 2003). However, the results of both Doyle and Endress (2010) and Mohr et al. (2013) support a position of Endressinia within the crown group of Magnoliineae, the well-supported clade of five families that is sister to Myristicaceae (Sauquet et al., 2003), and each study alone leads to use of this fossil to calibrate the crown node of this clade. Therefore, Endressinia provides a safe minimum age for the crown node of Magnoliineae (Figure 1). |
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phylogenetic reference(s)
Doyle, J.A. and Endress, P.K. 2010. Integrating Early Cretaceous fossils into the phylogeny of living angiosperms: Magnoliidae and eudicots. Journal of Systematics and Evolution, 48:1–35.
Mohr, B.A.R., Coiffard, C., and Bernardes-de-Oliveira, M.E.C. 2013. Schenkeriphyllum glanduliferum, a new magnolialean angiosperm from the Early Cretaceous of Northern Gondwana and its relationships to fossil and modern Magnoliales. Review of Palaeobotany and Palynology, 189:57–72.
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| tree image (click image for full size) | ||
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Figure 1 from Massoni et al. (2015).
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