A Late Devonian tree lycopsid with large strobili and isotomous roots

Area of Science:

• Paleobotany
• Paleoecology
• Evolutionary Biology

Background:

• Late Devonian tree lycopsids were key components of ancient forest ecosystems, influencing Earth's climate.
• Limited morphological diversity in their reproductive organs has hindered understanding of their ecological roles.

Purpose of the Study:

• To describe a new genus and species of tree lycopsid, Omprelostrobus gigas, from the Upper Devonian.
• To analyze the morphology of its strobili and associated root systems.
• To infer ecological strategies based on reproductive structures.

Main Methods:

• Paleontological excavation and analysis of fossilized plant remains.
• Morphological description of aerial axes, strobili, and roots.
• Comparative analysis with coeval lycopsid fossils.

Main Results:

• Discovery of Omprelostrobus gigas, featuring exceptionally large strobili for its time.
• Strobili exhibit dimorphic sporophylls with differentiated laminae, suggesting photosynthetic capacity.
• Associated roots are branched and lack rootlets, differing from typical root structures.

Conclusions:

• The large strobili indicate a significant reproductive investment strategy in Omprelostrobus gigas.
• This investment may have been crucial for survival in disturbed, flooded Late Devonian habitats.
• The findings enhance our understanding of early tree lycopsid reproductive biology and paleoecology.