Abstract
The fossil record suggests that, by the end of the early Devonian, vascular plants had diversified considerably but they were still relatively simple in their organization1–3. Most exhibit much-divided aerial shoots arranged in various patterns but lack clear differentiation into stems and leaves. I describe here a novel plant, discovered in the upper Lower Devonian of Gaspe, Quebec, Canada, whose anatomy is more complex and indicates a level of stem–leaf differentiation significantly more advanced than any known for trimerophytes or other taxa of this age. The presence of a lobed xylem, with mesarch protoxylem elements in major axes, and an elliptically shaped trace in first-order lateral axes in the new plant suggests that by the end of the early Devonian, the evolution of megaphyllous leaves has indeed begun, even though morphologically they were still much divided and non-laminate.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
