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EARLY CRETACEOUS TETRADS, ZONASULCULATE POLLEN, AND WINTERACEAE. I. TAXONOMY, MORPHOLOGY, AND ULTRASTRUCTURE
Author(s) -
Doyle James A.,
Hotton Carol L.,
Ward Jerome V.
Publication year - 1990
Publication title -
american journal of botany
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.218
H-Index - 151
eISSN - 1537-2197
pISSN - 0002-9122
DOI - 10.1002/j.1537-2197.1990.tb11395.x
Subject(s) - aptian , biology , reticulate , gondwana , botany , pollen , genus , cretaceous , paleontology , structural basin
Ulcerate pollen tetrads from the late Barremian‐early Aptian of Gabon, named Walkeripollis gabonensis gen. et sp. nov., resemble pollen of extant Winteraceae but have finer sculpture and a weakly calymmate tectum, like tetrads reported from the late Aptian‐Albian of Israel. Scanning and transmission electron microscopy reveal additional winteraceous features (tall muri, short columellae, ring of endexine around the ulcus), plus segmented muri recalling the reticulate, zonasulculate to inaperturate genus Afropollis, which is abundant in the Aptian‐Albian of Northern Gondwana. Afropollis also resembles Winteraceae in having tall muri and short columellae, but it has a thicker endexine. The new zonasulculate genus Schrankipollis, including S. mawhoubensis (Schrank) comb. nov. from the Aptian of Egypt and S. microreticulatus (Brenner) comb. nov. from the Potomac Group of Maryland, resembles Afropollis in structure of its muri but differs in its elliptical shape, finer reticulum, and restricted endexine.