TY - JOUR
T1 - New diversity among the Trochodendraceae from the Early/Middle Eocene Okanogan Highlands of British Columbia, Canada, and northeastern Washington State, United States
AU - Pigg, Kathleen B.
AU - Dillhoff, Richard M.
AU - DeVore, Melanie L.
AU - Wehr, Wesley C.
PY - 2007/5
Y1 - 2007/5
N2 - Newly recognized fossil infructescences and leaves of the Trochodendraceae are described from the Early/ Middle Eocene McAbee and One Mile Creek sites of British Columbia, Canada, and Republic, eastern Washington State, United States. Trochodendron drachukii Pigg, Dillhoff, DeVore, & Wehr sp. nov., from McAbee, is an infructescence similar to that of extant Trochodendron aralioides Sieb. & Zucc. but strongly paniculate rather than racemose. This new species is larger and more robust than those of the Eocene flora of Republic, Washington, and has attached fruits quite similar to both extant Trochodendron Sieb. & Zucc. and Miocene fossils from Asia and western North America. Associated leaves are similar to those of extant Trochodendron except for sometimes bearing short basal auriculate extensions of the lamina. They differ from Trochodendron nastae Pigg, Wehr, & Ickert-Bond leaves from Republic that have palmate rather than pinnate venation. Tetracentron hopkinsii Pigg, Dillhoff, DeVore, & Wehr sp. nov. from One Mile Creek and Tetracentron sp. from Republic have leaves remarkably like those of extant Tetracentron Oliver, firmly establishing the presence of this genus in the Eocene. This study demonstrates that within the Trochodendraceae, a poorly understood group within the eudicot grade, both extinct forms as well as plants with quite modern-appearing fruits and leaves were present by the Eocene in northwestern North America.
AB - Newly recognized fossil infructescences and leaves of the Trochodendraceae are described from the Early/ Middle Eocene McAbee and One Mile Creek sites of British Columbia, Canada, and Republic, eastern Washington State, United States. Trochodendron drachukii Pigg, Dillhoff, DeVore, & Wehr sp. nov., from McAbee, is an infructescence similar to that of extant Trochodendron aralioides Sieb. & Zucc. but strongly paniculate rather than racemose. This new species is larger and more robust than those of the Eocene flora of Republic, Washington, and has attached fruits quite similar to both extant Trochodendron Sieb. & Zucc. and Miocene fossils from Asia and western North America. Associated leaves are similar to those of extant Trochodendron except for sometimes bearing short basal auriculate extensions of the lamina. They differ from Trochodendron nastae Pigg, Wehr, & Ickert-Bond leaves from Republic that have palmate rather than pinnate venation. Tetracentron hopkinsii Pigg, Dillhoff, DeVore, & Wehr sp. nov. from One Mile Creek and Tetracentron sp. from Republic have leaves remarkably like those of extant Tetracentron Oliver, firmly establishing the presence of this genus in the Eocene. This study demonstrates that within the Trochodendraceae, a poorly understood group within the eudicot grade, both extinct forms as well as plants with quite modern-appearing fruits and leaves were present by the Eocene in northwestern North America.
KW - Eocene
KW - Okanogan Highlands
KW - Tetracentron
KW - Trochodendraceae
KW - Trochodendrales
KW - Trochodendron
UR - http://www.scopus.com/inward/record.url?scp=34247599682&partnerID=8YFLogxK
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U2 - 10.1086/512104
DO - 10.1086/512104
M3 - Article
AN - SCOPUS:34247599682
SN - 1058-5893
VL - 168
SP - 521
EP - 532
JO - International Journal of Plant Sciences
JF - International Journal of Plant Sciences
IS - 4
ER -