Assessing the Fossil Record of Asterids in the Context of Our Current Phylogenetic Framework¹

Abstract

The fossil record provides good evidence for the minimum ages of important events in the diversification and geographic spread of Asteridae, with earliest examples extending back to the Turonian stage of the Late Cretaceous (~89 Ma). Some of the fossil identifications accepted in previous considerations of asterid phylogeny do not stand up to careful scrutiny. Nevertheless, among major clades of asterids, there is good evidence for a range of useful anchor points. Here we provide a synopsis of fossil occurrences that we consider as reliable representatives of modern Asterid families and genera. In addition, we provide new examples documented by fossil dispersed pollen investigated by both light and scanning electron microscopy studies including representatives of Loranthaceae, Amaranthaceae, Cornaceae (incl. Nyssa L., Mastixia Blume, Diplopanax Hand.-Mazz.), Sapotaceae, Ebenaceae, Ericaceae, Icacinaceae, Oleaceae, Asteraceae, Araliaceae, Adoxaceae and Caprifoliaceae from Paleogene sites in Greenland, western North America, and central Europe, and of Lamiaceae and Asteraceae from the middle to late Miocene northeastern China. We emphasize that dispersed pollen, taken along with megafossil and mesofossil data, continue to fill gaps in our knowledge of the paleobotanical record.

A review of the plants of the Princeton chert (Eocene, British Columbia, Canada)

“…Isolated palynomorphs also have been described from the chert matrix (Boneham 1968;Zetter 2005, 2007;Manchester et al 2015a). Although Boneham (1968) found only Pistillipollenites pollen, along with fungal, bryophyte, and algal spores, more recent studies using single grain analysis whereby an individual pollen grain is studied with both light and scanning electron microscopy have yielded additional pollen taxa.…”

“…(Alismatales, Aponogetonaceae, . Layer 43 of the Princeton chert yielded samples of asterid pollen including members of Oleaceae (Lamiales), Aralia L.-like pollen (Apiales, Araliaceae), Viburnum L. (Dipsacales, Caprifoliaceae), and tentatively described asteraceous forms (Manchester et al 2015a). …”

“…Klymiuk also produced studies on fungi associated with Princeton chert plants (Klymiuk et al 2013a(Klymiuk et al , 2013bKlymiuk 2014). In addition to megafossil remains from the Princeton chert, pollen obtained from the chert matrix has been illustrated and described in several publications Zetter 2005, 2007;Manchester et al 2015a). To our knowledge, these occurrences have not been summarized.…”

A revised stratigraphy for the Palaeocene Agatdalen flora (Nuussuaq Peninsula, western Greenland): correlating fossiliferous outcrops, macrofossils, and palynological samples from phosphoritic nodules

“…Also, in the rich pollen record of the Agatdalen sediments no Cornus-type pollen grains have been documented, but Cornus pollen is usually easy to identify and is known from other Palaeocene sites (e.g. Manchester et al 2015).…”

Jurassic Pork: What Could a Jewish Time Traveler Eat?

“…A 55 million year old tropical forest contains abundant legumes, seeds, and fruits (Wing et al 2009). The asterids (lettuce, sunflowers, olives, carrots, potatoes, eggplants, tomatoes, peppers, tobacco, sweet potatoes), which appeared in the Cretaceous, also become widely available during the Early Cenozoic (Manchester et al 2015), as did nuts. Grasses, which includes wheat, maize, and rice, first occur in the Cretaceous, but grasslands do not spread worldwide until the middle and late Cenozoic (Strömberg 2011).…”