Light and scanning electron microscopic investigations of pollen of Ericales (Ericaceae, Sapotaceae, Ebenaceae, Styracaceae and Theaceae) from five lower and mid-Eocene localities.
- Author(s)
- Christa-Ch. Hofmann
- Abstract
As the SEM has been used in palaeo-palynology not routinely, affiliations of fossil pollen to botanical equivalents, based only on LM, are always equivocal. Here 29 Ericales taxa of 55.8 to 40 Myr age have been identified using LM andSEM, modifying the evolutionary and palaeo-biogeographical framework of some Ericales. Seven Ericaceae types, 17 Sapotaceae types), three Ebenaceae types, one Styracaceae type) and one Theaceae type were identified to tribe or genus level. A 56 Myr old Erica-type affiliated with Erica arborea might be the ancestor of the African Erica taxa, whilst a younger type with affinities with palaeo-arctic heather Erica might be the precursor of north European heathers. The Kalmia-type suggests a European origin and a wider geographical distribution for this type during the mid-Eocene, whilst a Rhododendron-type of contemporaneous age corroborates the establishment of numerous Rhododendron in Europe. Both the 56 Myr old Vaccinium-type, affiliated with temperate continental Asian taxa, and the Gaultheria-type, affiliated with several South American taxa, represent the oldest occurrences of these 5axa and suggest a Eurasian origin. The Sapotaceae are represented by 1. Sarcospermatoideae, with two Sarcosperma-types, 2. Chrysophylloideae, with three Chrysophylleae-types affiliated with South American Pouteria/Elaeoluma and one affiliated with Asian Planchonella/Sersalisia, and 3. Sapotoideae with three Mimusopeae/Isonandreae-types with mixed affinities, two Mimusopeae-types affiliated with African/Malegasy Mimusops/Vitellariopsis taxa, one Mimusopeae-type affiliated to South American Manilkara taxa, four Isonandreae-types affiliated twith SE Asian Palaquium, and one South American Sideroxylon-type. All Sapotaceae types are older than postulated in the literature by molecular dating analyses. Three Diospyros-types affiliated with African taxa corroborate a Gondwana-African origin of the genus. A Styrax-type resembles extant South American and East Asian taxa and is interpreted as being an early European ancestor of Styrax. The contemporaneous Camellia-type represents the oldest record of Camellia.
- Organisation(s)
- Department of Palaeontology
- Journal
- Botanical Journal of the Linnean Society
- Volume
- 187
- Pages
- 550-578
- No. of pages
- 28
- ISSN
- 0024-4074
- Publication date
- 2018
- Peer reviewed
- Yes
- Austrian Fields of Science 2012
- 105117 Palaeobotany
- Keywords
- Sustainable Development Goals
- SDG 3 - Good Health and Well-being
- Portal url
- https://ucrisportal.univie.ac.at/en/publications/1f538c26-9397-4032-bac0-0ab358c954b5