Explanation:
Animals lived in the water during the Mesozoic and on land in the Paleozoic. Animal complexity increased during the Paleozoic while the first flowering plants appeared in the Mesozoic era. ...
The Paleozoic era, not the Mesozoic era, had the first dinosaurs. The first mammals emerged in the Paleozoic era, not the Mesozoic era. The Mesozoic era, not the Paleozoic era, had the first animals with shells.
The answer is no, high biological fitness in one environment doesn’t have to be high in another environment.
Biological fitness is a term used in evolutionary biology and it is the quantitative representation of how a genotype (or phenotype) is successful (reproductively) in a certain environment. Fitness depends on environment so it changes if the environment changes. The fitness of a genotype is manifested through its phenotype, which is affected by the environment.
Sunlight
solar energy
water