Eocene Patagonia Fossils of the Daisy Family

Abstract

Fossil capitula and pollen grains of Asteraceae from the Eocene of Patagonia, southern Argentina, exhibit morphological features recognized today in taxa, such as Mutisioideae and Carduoideae, that are phylogenetically close to the root of the asteracean tree. This fossil supports the hypothesis of a South American origin of Asteraceae and an Eocene age of divergence and suggests that an ancestral stock of Asteraceae may have formed part of a geoflora developed in southern Gondwana before the establishment of effective dispersal barriers within this landmass.

Andean Origin and Diversification of the GenusPerezia, an Ancient Lineage of Asteraceae

“…Likewise, the morphological comparison among the species of Perezia and between Perezia and closely related genera also shows no characters that support the segregation of these two species from the genus (Katinas et al, 2008b;Katinas, 2012). Based on the morphological evidence the phylogeny matches the fossil record of the family (Barreda et al, 2010) and the biogeographical scenario proposed for early members of the family in southern South America (Katinas et al, 2013). It seems that the morphological phylogeny presented here is a better fit for what we know about Earth history.…”

“…This southern location is also congruent with the fossil record of the early diverging lineages of the family that includes Perezia. Several fossils of early branching lineages of Asteraceae have been found from the Paleogene in southwestern Argentina, the earliest from the middle Eocene (~50 MYA) (Barreda et al, 2010(Barreda et al, , 2012. The first and only records to date of fossil pollen of Nassauvieae are from the early Miocene found in Argentina along eastern coast of Patagonia.…”

Lettuce Costunolide Synthase (CYP71BL2) and Its Homolog (CYP71BL1) from Sunflower Catalyze Distinct Regio- and Stereoselective Hydroxylations in Sesquiterpene Lactone Metabolism

“…The structure of the purchased costunolide was confirmed by one-dimensional and two-dimensional NMR analyses. Experiments performed were onedimensional proton, one-dimensional 13 C with proton decoupling, 13 C attached proton test with proton decoupling, COSY, Total Correlation Spectroscopy, Heteronuclear Single Quantum Coherence, and Heteronuclear Multiple Bond Coherence.…”

“…NMR Analyses-For structural analysis of 8␤-hydroxy-GAA, 1 H and 13 C NMR spectra were measured in 5-mm standard NMR tubes at 400.13 and 100.6 MHz on a Bruker AVANCE 400 spectrometer equipped with 5-mm inverse probe with triple axis gradients. Chemical shifts (␦) for both 13 C and 1 H were referenced to internal tetramethylsilane.…”

“…Asteraceae first appeared in South America ϳ50 million years ago (13,14) and has since radiated on all continents to become one of the largest families of land plants (15). Throughout the diversification of this family, most Asteraceae plants retain STLs as a major secondary metabolic constituents, suggesting a positive selection of STL biosynthesis in the adaptive evolution.…”