Where: Sagaing, Myanmar (23.2° N, 94.3° E)
• Paleocoordinates: 11.5° N, 97.6° E (Wright 2013)
• 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 227670: authorized by Bethany Allen, entered by Bethany Allen on 26.10.2022
Creative Commons license: CC0 (CC0)
Taxonomic list
Saxosporis sp. Krutzsch 1963 hornwort | |
Pteridopsida | |
Deltoidospora sp. Miner 1935
Crassoretitriletes vanraadshooveni Hopping and Muller 1968 | |
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 | |
Cicatricososporites eocenicus Jansonius and Hills 1976
Cicatricosisporites sp. Potonie and Gelletich 1933 | |
Dicolpopollis | |
Retistephanocolpites | |
"Retistephanocolpites williamsi" = Retistephanocolpites williamsii
"Retistephanocolpites williamsi" = Retistephanocolpites williamsii Germeraad et al. 1968 | |
Angiospermae | |
Palmaepollenites kutchensis, Longapertites retipilatus, Longapertites rugulatus, Spinizonocolpites prominatus
Palmaepollenites kutchensis Venkatachala and Kar 1969 palm | |
Proxapertites operculatus Van der Hammen 1956 | |
Tetracolpites sp. Srivastava 1967 | |
Campnosperma sp. Thwaites 1854 cashew | |
cf. Amanoa sp. Aublet 1775 | |
Euphorbiaceae indet. Jussieu 1789 spurge | |
Berlinia sp. Solander 1849 legume | |
Magnoliaceae indet. de Jussieu 1789 magnolia | |
Dicotyledoneae | |
Sapotaceoidaepollenites sp. Potonié et al. 1950
Palaquium sp. Blanco 1837 | |
Lanagiopollis sp. Morley 1982 | |
Acrostichum | |
Acrostichum sp. Linnaeus 1753 |