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 227785: authorized by Bethany Allen, entered by Bethany Allen on 31.10.2022
Creative Commons license: CC BY (attribution)
Taxonomic list
Saxosporis sp. Krutzsch 1963 hornwort | |
Polypodiopsida | |
Laevigatosporites sp. Ibrahim 1933
Verrucatosporites sp. Pflug and Thomson 1953
Verrucatosporites usmensis Germeraad et al. 1968 | |
Pterisisporites sp. Sung and Zheng | |
Pteridopsida | |
Deltoidospora sp. Miner 1935 | |
Angiospermae | |
Cupuliferoipollenites sp. Potonié | |
Euphorbiaceae indet. Jussieu 1789 spurge | |
cf. Berlinia sp. Solander 1849 legume | |
Cupanieidites sp. Cookson and Pike 1954 soapberry | |
Iugopollis sp. Venkatachala and Rawat mahogany | |
Discoidites sp. Muller mallow
Discoidites cf. pilosus mallow | |
Liliacidites sp. Couper 1953 | |
Proxapertites operculatus Van der Hammen 1956 | |
Rubiaceae indet. Jussieu 1789 coffee | |
Ilexpollenites sp. Thiergart 1937 | |
Dicotyledoneae | |
Lanagiopollis sp. Morley 1982 | |
Marginipollis sp. Clarke 1968 | |
Heterocolpites sp. Van der Hammen 1956 | |
Retitricolpites | |
Retitricolpites sp. Van der Hammen 1956 | |
Dicolpopollis | |
Lycopodiopsida | |
? Selaginella sp. Beauvois 1804 spikemoss |