Sources:
https://hort.extension.wisc.edu/articles/cycads/
https://www.sciencedirect.com/science/article/pii/B9780123749840003363
https://www.cmnh.org/paleobotany-paleoecology
https://www.farandwide.com/s/national-parks-no-longer-exist-1795c23e03294277
https://www.nps.gov/articles/fossil-cycad-national-monument.htm
https://www.biologydiscussion.com/gymnosperm/top-9-economic-uses-of-cycas-cycadales/22602
https://www.fotw.info/flags/vu.html
https://plants.ces.ncsu.edu/plants/zamia-integrifolia/
https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/cycad