Where: Sagaing, Myanmar (23.2° N, 94.3° E: paleocoordinates 14.7° N, 94.2° E)
• coordinate stated in text
• small collection-level geographic resolution
When: Yaw Formation, Late/Upper Eocene (37.2 - 33.9 Ma)
• "U–Pb dating of a tuff layer (Licht et al. 2019), magnetostratigraphy, U–Pb apatite dating and apatite fission track dating (Westerweel et al., 2020) provide an age of c. 38–37 Ma, which is also supported by the palynological evidence discussed below and in Huang et al. 2020, Huang et al. 2018." (Huang et al. 2023)
• bed-level stratigraphic resolution
Environment/lithology: fluvial; lithified sandstone and mudstone
Size class: microfossils
Collection methods: chemical
• "Two palynological processing methods were performed to ensure maximum recovery. One set of samples was processed for quantitative analysis. The processing was as follows: 1.3 g of sample was boiled in 10% sodium pyrophosphate, and then treated with 10% HCl, and sieved with 5 μm and 212 μm meshes. The sample was then heated in acetolysis mixture to 100 °C. Bromoform-treatment was applied to separate any remaining inorganic fraction to produce residue. A second set of selected samples was processed mainly for microphotography. The processing method was as follows: 30 g of washed and dried sample was treated with 10% HCl and 40% HF. Then a heavy liquid separation was used to separate the organic and remaining inorganic fractions. All resulting residues were mounted on a slide in glycerin and sealed with paraffin for light microscope (LM) observation. Residues were further used for analysis with LM and scanning electron microscopy (SEM) at the Department of Palaeontology (DoP), University of Vienna, Austria. Details on the two methods were presented in Huang et al. (2020)." (Huang et al. 2023)
Primary reference: H. Huang, R. J. Morley, A. Licht, G. Dupont-Nivet, D. Pérez-Pinedo, J. Westerweel, Z. Win, D. Wa Aung, E. Budi Lelono, G. N. Aleksandrova, R. K. Saxena and C. Hoorn. 2023. A proto-monsoonal climate in the late Eocene of Southeast Asia: evidence from a sedimentary record in central Myanmar. Geoscience Frontiers 14(1):101457 [B. Allen/B. Allen]more details
Purpose of describing collection: paleoecologic analysis
PaleoDB collection 227676: authorized by Bethany Allen, entered by Bethany Allen on 26.10.2022
Creative Commons license: CC BY (attribution)
Taxonomic list
Saxosporis sp. Krutzsch 1963 hornwort | |
Equisetopsida | |
Inaperturopollenites hiatus Thomson and Pflug 1953 | |
Ranunculacidites | |
Ranunculacidites operculatus Jaramillo and Dilcher 2001 | |
Retibrevitricolpites triangulatus | |
Retibrevitricolpites triangulatus van Hoeken-Klinkenberg 1966 | |
Pteridopsida | |
Deltoidospora sp. Miner 1935 | |
Polypodiopsida | |
Verrucatosporites sp., Verrucatosporites usmensis, Meyeripollis naharkotensis, Laevigatosporites sp.
Verrucatosporites sp. Pflug and Thomson 1953
Verrucatosporites usmensis Germeraad et al. 1968
Meyeripollis naharkotensis Baksi 1970
Laevigatosporites sp. Ibrahim 1933 | |
Angiospermae | |
Proxapertites sp. Van der Hammen 1956
Proxapertites operculatus Van der Hammen 1956 | |
Liliacidites sp. Couper 1953 | |
Ilexpollenites sp. Thiergart 1937 | |
Rubiaceae indet. Jussieu 1789 coffee | |
Dicotyledoneae | |
Myrtaceidites sp. Cookson and Pike 1960 | |
Lecythidaceae indet. Poiteau 1825 | |
Sapotaceoidaepollenites sp. Potonié et al. 1950 | |
Angiospermae | |
Margocolporites sp. Ramanajuan 1966 legume | |
Euphorbiaceae indet. Jussieu 1789 spurge | |
Cupuliferoipollenites sp. Potonié | |
Discoidites sp. Muller mallow
Discoidites angulosus mallow | |
Campnosperma sp. Thwaites 1854 cashew
cf. Gluta sp. Linnaeus 1771 cashew | |
Meliaceae indet. de Jussieu 1789 mahogany | |
Sapindaceae indet. de Jussieu 1789 soapberry | |
Magnoliaceae indet. de Jussieu 1789 magnolia | |
Concentricystes sp. Rossignol 1962 acritarchs | |
Acrostichum | |
Acrostichum sp. Linnaeus 1753 |