Gymnosperms, including cycads, ginkgoes and conifers were the dominant plants during the Mesozoic era. Cycads were particularly diverse and widespread, forming extensive forests in many parts of the world. These plants were well adapted to the environmental conditions of the Mesozoic, including high levels of carbon dioxide and warm temperatures.

Cycads were a rich source of nutrients, providing Mesozoic herbivores with essential vitamins, minerals and proteins. Their leaves were packed with carbohydrates and fiber, while their seeds were high in fat and protein. In addition, cycads produced toxic chemicals that helped deter predators, making them a relatively safe food source for herbivores.

Mesozoic herbivores that fed on cycads included dinosaurs, mammals and birds. Some of the most notable herbivores that relied heavily on cycads were sauropods, such as the Brachiosaurus and Diplodocus. These giant dinosaurs had long necks and tails that allowed them to reach the tops of cycad trees. Other herbivores that ate cycads included stegosaurs, such as the Stegosaurus and Triceratops. These dinosaurs had tough, beak-like mouths that were well suited for crushing cycad leaves and seeds.

The abundance and nutritional value of cycads made them a key part of the food chain during the Mesozoic era. These plants played a crucial role in supporting the diverse and thriving herbivore populations of the time.