TY - JOUR
T1 - Glandulocalyx upatoiensis, a fossil flower of Ericales (Actinidiaceae/ Clethraceae) from the Late Cretaceous (Santonian) of Georgia, USA
AU - Schõnenberger, Jũrg
AU - Balthazar, Maria Von
AU - Takahashi, Masamichi
AU - Xiao, Xianghui
AU - Crane, Peter R.
AU - Herendeen, Patrick S.
N1 - Funding Information:
P.R.C. and P.S.H. thank Andrew Drinnan, Jennifer Keller, Hallie Sims and Richard Lupia for help with fieldwork. John Brent, Fort Benning Military Reservation, provided access to the localities on Upatoi Creek and assisted with fieldwork. We are grateful to Kentaro Uesugi for assistance with the tomographic study at SPring-8. We used the X-ray micro-CT system at BL20B2 in SPring-8 with the approval of the Japan Synchrotron Radiation Research Institute ( proposal 2008A1027). Use of the Advanced Photon Source, an Office of Science User Facility operated for the US Department of Energy (DOE) Office of Science by Argonne National Laboratory, was supported by the US DOE under Contract no. DE-AC02-06CH11357. We thank Nobuhito Nango and Kazutaka Nomura (Ratoc System Engineering) for their technical support in three-dimensional reconstruction software. We are grateful to Susanne Sontag and Susanne Pamperl for SEM preparations of extant floral material and help with graphics at the University of Vienna. We thank Peter K. Endress and an anonymous colleague for critically reviewing the manuscript. This work was supported by a grant-in-aid (18570083) from the Ministry of Education, Science, and Culture of Japan to M.T. This work was initiated with support from the Japan Society for the Promotion of Science (S-97128, S-98106) and the National Science Foundation (EAR-9614672) to P.R.C., and completed, in part, with financial support from the World Class University program of the National Research Foundation of Korea (R33-10089).
PY - 2012/4
Y1 - 2012/4
N2 - Background and Aims Ericales are a major group of extant asterid angiosperms that are well represented in the Late Cretaceous fossil record, mainly by flowers, fruits and seeds. Exceptionally well preserved fossil flowers, here described as Glandulocalyx upatoiensis gen. sp. nov., from the Santonian of Georgia, USA, yield new detailed evidence of floral structure in one of these early members of Ericales and provide a secure basis for comparison with extant taxa. Methods The floral structure of several fossil specimens was studied by scanning electron microscopy (SEM), light microscopy of microtome thin sections and synchrotron-radiation X-ray tomographic microscopy (SRXTM). For direct comparisons with flowers of extant Ericales, selected floral features of Actinidiaceae and Clethraceae were studied with SEM. Key Results Flowers of G. upatoiensis have five sepals with quincuncial aestivation, five free petals with quincuncial aestivation, 2028 stamens arranged in a single series, extrorse anther orientation in the bud, ventral anther attachment and a tricarpellate, syncarpous ovary with three free styles and numerous small ovules on axile, protruding-diffuse and pendant placentae. The calyx is characterized by a conspicuous indumentum of large, densely arranged, multicellular and possibly glandular trichomes. Conclusions Comparison with extant taxa provides clear evidence for a relationship with core Ericales comprised of the extant families Actinidiaceae, Roridulaceae, Sarraceniaceae, Clethraceae, Cyrillaceae and Ericaceae. Within this group, the most marked similarities are with extant Actinidiaceae and, to a lesser degree, with Clethraceae. More detailed analyses of the relationships of Glandulocalyx and other Ericales from the Late Cretaceous will require an improved understanding of the morphological features that diagnose particular extant groups defined on the basis of molecular data.
AB - Background and Aims Ericales are a major group of extant asterid angiosperms that are well represented in the Late Cretaceous fossil record, mainly by flowers, fruits and seeds. Exceptionally well preserved fossil flowers, here described as Glandulocalyx upatoiensis gen. sp. nov., from the Santonian of Georgia, USA, yield new detailed evidence of floral structure in one of these early members of Ericales and provide a secure basis for comparison with extant taxa. Methods The floral structure of several fossil specimens was studied by scanning electron microscopy (SEM), light microscopy of microtome thin sections and synchrotron-radiation X-ray tomographic microscopy (SRXTM). For direct comparisons with flowers of extant Ericales, selected floral features of Actinidiaceae and Clethraceae were studied with SEM. Key Results Flowers of G. upatoiensis have five sepals with quincuncial aestivation, five free petals with quincuncial aestivation, 2028 stamens arranged in a single series, extrorse anther orientation in the bud, ventral anther attachment and a tricarpellate, syncarpous ovary with three free styles and numerous small ovules on axile, protruding-diffuse and pendant placentae. The calyx is characterized by a conspicuous indumentum of large, densely arranged, multicellular and possibly glandular trichomes. Conclusions Comparison with extant taxa provides clear evidence for a relationship with core Ericales comprised of the extant families Actinidiaceae, Roridulaceae, Sarraceniaceae, Clethraceae, Cyrillaceae and Ericaceae. Within this group, the most marked similarities are with extant Actinidiaceae and, to a lesser degree, with Clethraceae. More detailed analyses of the relationships of Glandulocalyx and other Ericales from the Late Cretaceous will require an improved understanding of the morphological features that diagnose particular extant groups defined on the basis of molecular data.
KW - Actinidiaceae
KW - Clethraceae
KW - Ericales
KW - Glandulocalyx upatoiensis
KW - Late Cretaceous
KW - Santonian
KW - flowers
KW - fossils
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U2 - 10.1093/aob/mcs009
DO - 10.1093/aob/mcs009
M3 - Article
C2 - 22442339
AN - SCOPUS:84859175168
SN - 0305-7364
VL - 109
SP - 921
EP - 936
JO - Annals of botany
JF - Annals of botany
IS - 5
ER -