Dinosaur Extinction Changed Plant Evolution | A Bioscience Publishing Platform

Dinosaur Extinction Changed Plant Evolution

Published:12 Sep.2022 Source:German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig

To answer this question, a research team analysed fossil and living palms today. They first confirmed the common scientific assumption that many palm species at the time of the dinosaurs bore large fruits and were covered with spines and thorns on their trunks and leaves. However, the research team found that the "evolutionary speed" with which new palm species with small fruits arose during the megaherbivore gap decreased, whereas the evolutionary speed of those with large fruits remained almost constant. The size of the fruits themselves, however, also increased.

So, there were palms with large fruits even after the extinction of the dinosaurs. Apparently, much smaller animals could also eat large fruits and spread the seeds with their excretions. “We were thus able to refute the previous scientific assumption that the presence of large palm fruits depended exclusively on megaherbivores,” says the study’s first author. “We therefore assume that the lack of influence of large herbivores led to denser vegetations in which plants with larger seeds and fruits had an evolutionary advantage.” However, the defence traits of the plants; spines and thorns on leaves and stems, showed a different picture: the number of palm species with defence traits decreased during the megaherbivore gap. However, they returned in most palm species when new megaherbivores evolved, in contrast to the changes in fruits, which persisted.