Disparity of cycad leaves dispels the living fossil metaphor

Autor(en)
Mario Coiro, Leyla Jean Seyfullah
Abstrakt

The living fossil metaphor is tightly linked with the cycads. This group of gymnosperms is supposed to be characterised by long-term morphological stasis, particularly after their peak of diversity and disparity in the Jurassic. However, no formal test of this hypothesis exists. Here, we use a recent phylogenetic framework and an improved character matrix to reconstruct the Disparity Through Time for cycad leaves using a Principal Coordinate Analysis and employing Pre-Ordination Ancestral State Reconstruction to test the impact of sampling on the results. Our analysis shows that the cycad leaf morsphospace expanded up to the present, with numerous shifts in its general positioning, independently of sampling biases. Moreover, they also show that Zamiaceae expanded rapidly in the Early Cretaceous and continued to expand up to the present, while now-extinct clades experienced a slow contraction from their peak in the Triassic. We also show that rates of evolution were constantly high up to the Early Cretaceous, and then experienced a slight decrease in the Paleogene, followed by a Neogene acceleration. These results show a much more dynamic history for cycads, and suggest that the 'living fossil' metaphor is actually a hindrance to our understanding of their macroevolution.

Organisation(en)
Institut für Paläontologie
Externe Organisation(en)
Ronin Institute for Independent Scholarship
Journal
Communications Biology
Band
7
Seiten
328
ISSN
2399-3642
DOI
https://doi.org/10.1038/s42003-024-06024-9
Publikationsdatum
12-2024
Peer-reviewed
Ja
ÖFOS 2012
105117 Paläobotanik, 106012 Evolutionsforschung, 106042 Systematische Botanik
Schlagwörter
ASJC Scopus Sachgebiete
Agricultural and Biological Sciences(all), Biochemistry, Genetics and Molecular Biology(all), Medicine (miscellaneous)
Sustainable Development Goals
SDG 15 – Leben an Land
Link zum Portal
https://ucrisportal.univie.ac.at/de/publications/disparity-of-cycad-leaves-dispels-the-living-fossil-metaphor(9e747cce-e8a9-4806-8461-534f7ec03c60).html