Campanian Stage

What happened during this time?

• Palms (Arecaceae) are the first modern family of monocots appearing in the fossil record around this time

• Based on fossil leaves, modern-looking tropical rainforests already existed since 80 Ma in northeastern Africa in an area corresponding to 10 % of the modern Amazonian or 25 % of the Congolese (Coiffard et al. 2023)

• Study by Mallon and Anderson (2013) indicates that during this time food resources were limiting for dinosaurs, and that niche partitioning was present for these animals

  • Plants  weren't super-abundant to support large herbivores; species had to share available food sources by specializing on different types of vegetation

  • Ankylosaurs probably specialized on eating ferns, because they stood low to the ground, and their wide beaks would have allowed them to feed efficiently on abundant, relatively low-nutrient plants.

    • However, within this group, the family known as nodosaurids (clubless ankylosaurs) had more efficient jaw mechanics that might have enabled them to include tougher plants in their diets. 

  • Ceratopsids had skulls that suggest they were adapted to feeding on mid-sized shrubs

  • Taller hadrosaurs were less picky and would have fed on anything within reach.

• Mite houses, or acarodomatia, found on the leaves from angiosperm leaves discovered in the Kaiparowits Formation (76.6-74.5 Ma) in southern UT (Macracken, Miller, and Labandeira 2019)

  • These structures facilitate tri-trophic interactions between the host plant, its fungi or herbivore adversaries, and fungivorous or predaceous mites by providing shelter for the mite consumers