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Summary Lycopodiaceae are one of three surviving families of lycopsids, a lineage of vascular plants with a fossil history dating to at least the Early Devonian or perhaps the Late Silurian (c. 415 Ma). Many fossils have been linked to crown Lycopodiaceae, but the lack of well‐preserved material has hindered definitive recognition of this group in the paleobotanical record.New, exceptionally well‐preserved permineralized lycopsid fossils from the Early Cretaceous (125.6 ± 1.0 Ma) of Inner Mongolia, China, were examined in detail using acetate peel and micro‐computed tomography techniques. The anatomy of extant Lycopodiaceae was analyzed for comparison using fluorescence microscopy. Phylogenetic relationships of the new fossil to extant Lycopodiaceae were evaluated using parsimony and maximum likelihood analyses.Lycopodicaulis oellgaardiigen. et sp. nov. provides the earliest unequivocal and best‐documented evidence of crown Lycopodiaceae and Lycopodioideae, based on anatomically‐preserved fossil material.Recognition ofLycopodicaulisin Asia during the Early Cretaceous indicates the presence of crown Lycopodiaceae at this time, and striking similarities of stem anatomy with extant species provide a framework for the understanding of the interaction of branching and vascular anatomy in crown‐group lycopsids.
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Cretaceous pollen cone with three‐dimensional preservation sheds light on the morphological evolution of cycads in deep time
Summary The Cycadales are an ancient and charismatic group of seed plants. However, their morphological evolution in deep time is poorly understood. While molecular divergence time analyses estimate a Cretaceous origin for most major living cycad clades, much of the extant diversity is inferred to be a result of Neogene diversifications. This leads to long branches throughout the cycadalean phylogeny that, with few exceptions, have yet to be rectified by unequivocal fossil cycads.We report a permineralized pollen cone from the Campanian Holz Shale located in Silverado Canyon, CA, USA (c.80 million yr ago). This fossil was studied via serial sectioning, SEM, 3D reconstruction and phylogenetic analyses.Microsporophyll and pollen morphology indicate this cone is assignable toSkyttegaardia, a recently described genus based on disarticulated lignitized microsporophylls from the Early Cretaceous of Denmark. Data from this new species, including a simple cone architecture, anatomical details and vasculature organization, indicate cycadalean affinities forSkyttegaardia. Phylogenetic analyses support this assignment and recoverSkyttegaardiaas crown‐group Cycadales, nested within Zamiaceae.Our findings support a Cretaceous diversification for crown‐group Zamiaceae, which included the evolution of morphological divergent extinct taxa with unique traits that have yet to be widely identified in the fossil record.
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- Award ID(s):
- 1953993
- PAR ID:
- 10402552
- Publisher / Repository:
- Wiley-Blackwell
- Date Published:
- Journal Name:
- New Phytologist
- Volume:
- 238
- Issue:
- 4
- ISSN:
- 0028-646X
- Page Range / eLocation ID:
- p. 1695-1710
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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