TY - JOUR
T1 - Leaves of Podozamites and Pseudotorellia from the Early Cretaceous of Mongolia
T2 - stomatal patterns and implications for relationships
AU - Shi, Gongle
AU - Herrera, Fabiany
AU - Herendeen, Patrick S.
AU - Leslie, Andrew B.
AU - Ichinnorov, Niiden
AU - Takahashi, Masamichi
AU - Crane, Peter R.
N1 - Funding Information:
We thank T. Gombosuren and O. Nyamsambuu for assistance with fieldwork in Mongolia, D. E. G. Briggs and S. Butts for use of facilities in the Yale University invertebrate palaeontology laboratory, I. Glasspool and S. Grant for curatorial assistance, and C. Thornton, L. Nowack, A. Basey, B. Cooper, D. Bruzzese and S. Crane for help sorting the fossil material. We are also grateful to E. V. Bugdaeva and N. V. Nosova for supplying key references, and Z. Zhou and M. Pole for constructive discussions. Funding for this work was provided by NSF grant DEB-1348456 to PSH and PRC, Grants-in-Aid for Scientific Research (21405010 and 24405015) from the Japan Society for the Promotion of Science to MT, and National Natural Science Foundation of China grant 41206173 and Youth Innovation Promotion Association, CAS (2017359) to GS.
Funding Information:
Division of Environmental Biology, Japan Society for the Promotion of Science, National Natural Science Foundation of China, Youth Innovation Promotion Association of the Chinese Academy of Sciences We thank T. Gombosuren and O. Nyamsambuu for assistance with fieldwork in Mongolia, D. E. G. Briggs and S. Butts for use of facilities in the Yale University invertebrate palaeontology laboratory, I. Glasspool and S. Grant for curatorial assistance, and C. Thornton, L. Nowack, A. Basey, B. Cooper, D. Bruzzese and S. Crane for help sorting the fossil material. We are also grateful to E. V. Bugdaeva and N. V. Nosova for supplying key references, and Z. Zhou and M. Pole for constructive discussions. Funding for this work was provided by NSF grant DEB-1348456 to PSH and PRC, Grants-in-Aid for Scientific Research (21405010 and 24405015) from the Japan Society for the Promotion of Science to MT, and National Natural Science Foundation of China grant 41206173 and Youth Innovation Promotion Association, CAS (2017359) to GS.
Publisher Copyright:
© 2017, © The Trustees of the Natural History Museum, London 2017. All rights reserved.
PY - 2018/1/26
Y1 - 2018/1/26
N2 - Strap-shaped, parallel-veined leaves of Podozamites and Pseudotorellia are among the most common fossils in Late Triassic to Early Cretaceous floras from the Northern Hemisphere. Podozamites is considered to be the leaf of a voltzian conifer, but its cuticle is poorly known, whereas Pseudotorellia, with a thick cuticle and haplocheilic stomata, is commonly considered to be the leaf of a ginkgoalean. Here we describe the leaf morphology, cuticle and stomata of Podozamites and Pseudotorellia based on excellently preserved material from the Early Cretaceous of central Mongolia. Podozamites harrisii sp. nov. has transversely oriented, paracytic (probably syndetocheilic) stomata that are regularly arranged in longitudinal files. Pseudotorellia resinosa sp. nov. and Pseudotorellia palustris sp. nov. have scattered, longitudinally oriented stomata in which the two guard cells are sunken and surrounded by 2–5 specialized lateral subsidiary cells and 1–3 unspecialized polar cells. Association evidence and similarities in cuticular structure suggest that Podozamites harrisii was produced by the same plant as the seed cone Krassilovia. The distinctive stomatal pattern of Podozamites harrisii and Krassilovia is also seen in some species of Swedenborgia and Cycadocarpidium, suggesting these plants may all belong to the same natural group. Cycadocarpidium, Krassilovia and Swedenborgia have previously been treated as conifers, but their transversely oriented, paracytic stomata hint instead at a possible relationship with Bennettitales and Gnetales.
AB - Strap-shaped, parallel-veined leaves of Podozamites and Pseudotorellia are among the most common fossils in Late Triassic to Early Cretaceous floras from the Northern Hemisphere. Podozamites is considered to be the leaf of a voltzian conifer, but its cuticle is poorly known, whereas Pseudotorellia, with a thick cuticle and haplocheilic stomata, is commonly considered to be the leaf of a ginkgoalean. Here we describe the leaf morphology, cuticle and stomata of Podozamites and Pseudotorellia based on excellently preserved material from the Early Cretaceous of central Mongolia. Podozamites harrisii sp. nov. has transversely oriented, paracytic (probably syndetocheilic) stomata that are regularly arranged in longitudinal files. Pseudotorellia resinosa sp. nov. and Pseudotorellia palustris sp. nov. have scattered, longitudinally oriented stomata in which the two guard cells are sunken and surrounded by 2–5 specialized lateral subsidiary cells and 1–3 unspecialized polar cells. Association evidence and similarities in cuticular structure suggest that Podozamites harrisii was produced by the same plant as the seed cone Krassilovia. The distinctive stomatal pattern of Podozamites harrisii and Krassilovia is also seen in some species of Swedenborgia and Cycadocarpidium, suggesting these plants may all belong to the same natural group. Cycadocarpidium, Krassilovia and Swedenborgia have previously been treated as conifers, but their transversely oriented, paracytic stomata hint instead at a possible relationship with Bennettitales and Gnetales.
KW - Early Cretaceous
KW - Ginkgo
KW - Podozamites
KW - Pseudotorellia
KW - paracytic stoma
KW - voltzian
UR - http://www.scopus.com/inward/record.url?scp=85010641899&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85010641899&partnerID=8YFLogxK
U2 - 10.1080/14772019.2016.1274343
DO - 10.1080/14772019.2016.1274343
M3 - Article
AN - SCOPUS:85010641899
SN - 1477-2019
VL - 16
SP - 111
EP - 137
JO - Journal of Systematic Palaeontology
JF - Journal of Systematic Palaeontology
IS - 2
ER -