|
|
||||||||
Paleobotany |
2SOLS Faculty & Admin, Arizona State University, Box 874501, Tempe, Arizona 85287-4501 USA; 3Field Museum of Natural History, 1400 S. Lake Shore Drive, Chicago, Illinois 60605 USA; 4Laboratory of Systematic and Evolutionary Botany & Herbarium, Institute of Botany, the Chinese Academy of Sciences,Beijing 100093, China
Liquidambar changii Pigg, Ickert-Bond & Wen sp. nov. (Altingiaceae) is established for anatomically preserved, middle Miocene infructescences from Yakima Canyon, Washington, USA. Specimens are spherical,
2.5 cm in diameter, and have
2530 tightly packed, bilocular fruits per head. Fruits are 3.44.7 mm wide x 2.63.5 mm long and wedge shaped, fused at the base, and free distally. Each locule contains 12 mature, elongate seeds proximally and 59 aborted seeds of more irregular shape distally. Mature seeds are 1.5 mm long x 1.2 mm wide, elongate, and triangular transversely, with a slight flange. Seeds have a seed coat for which three zones can be well defined, a uniseriate outer palisade layer, a middle region of isodiametric cells comprising most of the integument, and a uniseriate inner layer of tangentially elongate cells lining the embryo cavity. Liquidambar changii is most similar to the eastern Asian L. acalycina H.-T. Chang on features of infructescence, fruit, and seed morphology and quite unlike the North American L. styraciflua L. and other species. Such a close relationship between these two species supports a Beringian biogeographic track between eastern Asia and western North America during the Miocene. Previous phylogenetic and allozyme analysis of modern Liquidambar demonstrates a close relationship between North American-western Asian taxa and suggests a North Atlantic biogeographic track in the middle Miocene. Together, these biogeographic tracks underscore the complexity of the biogeographic history of the Altingiaceae in the Northern Hemisphere throughout the Neogene.
Key Words: Altingia Altingiaceae biogeography fossil fruit infructescence Liquidambar Miocene silicification
This article has been cited by other articles:
![]() |
S. M. Ickert-Bond, K. B. Pigg, and J. Wen Comparative infructescence morphology in Altingia (Altingiaceae) and discordance between morphological and molecular phylogenies Am. J. Botany, July 1, 2007; 94(7): 1094 - 1115. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. M. Ickert-Bond, K. B. Pigg, and J. Wen Comparative infructescence morphology in Liquidambar (Altingiaceae) and its evolutionary significance Am. J. Botany, August 1, 2005; 92(8): 1234 - 1255. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. B. Pigg and M. L. DeVore Shirleya grahamae gen. et sp. nov. (Lythraceae), Lagerstroemia-like fruits from the middle Miocene Yakima Canyon flora, central Washington State, USA Am. J. Botany, February 1, 2005; 92(2): 242 - 251. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |