The exine ultrastructure of Williamsoniella coronata Thomas from the Bajocian of Yorkshire (United Kingdom) was investigated with light, scanning electron, and transmission electron microscopy. The pollen averages 16.5 μm alongitsshort axisand24.5μmalongitslongaxis andismonosulcate, and thenonapertural sculpturingisdistinctly verrucate. The pollen wallishomogeneous, and the sulcus membraneiscomposedofthin exine withscattered small granules. The pollen grains differ in exine sculpturing and pollen wall ultrastructure from pollen grains of the bennettitalean taxa Cycadeoidea dacotensis (MacBride) Ward and Leguminanthus siliquosis (Leuthardt) Kraeusel. They are similar todispersed pollen grainsof Granamonocolpites luisae Herbst from the Triassic Chinle Formation of the United States, supporting the bennettitalean affinity of these dispersed pollen grains. The Bennettitales are palynologically characterized by monosulcate "boat-shaped" pollen with a homogeneous or granular pollen wall ultrastructure.
| Identifer | oai:union.ndltd.org:ETSU/oai:dc.etsu.edu:etsu-works-18509 |
| Date | 01 November 2009 |
| Creators | Zavialova, Natalia, Van konijnenburg-Van Cittert, Johanna, Zavada, Michael |
| Publisher | Digital Commons @ East Tennessee State University |
| Source Sets | East Tennessee State University |
| Detected Language | English |
| Type | text |
| Source | ETSU Faculty Works |
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