1 "11 Facts about Endangered Species." DoSomething.org Facts. Accessed August 18, 2017.
2 "20 of the World's Weirdest Endangered Animal Species." Web Ecoist. Accessed: August 31, 2017.
3 Bland, Alestair. "These Animals Might Go Extinct Because No One Wants to Eat Them." NPR. April 24, 2015. Accessed: August 31, 2017.
4 Cressey, Daniel. "Cost of Conserving Global Set at $76 Billion." Scientific American. October 12, 2012. Accessed August 27, 2017.
5 “Extinct Animal List.” Extinct Animal Facts. Accessed August 17, 2017.
6 Greenwald, Noah. “Listing Species Under The Endangered Species Act.” Center for Biological Diversity. Accessed August 17, 2017.
7 ———.The Extinction Crisis.” Center for Biological Diversity. Accessed August 17, 2017.
8 Harmon, Katherine. "No Sex Needed: All-Female Lizards Species Cross Their Chromosomes to Make Babies." Scientific American. February 21, 2010. Accessed: September 1, 2017.
9 Hartston, William. "Top 10 Facts about Extinction." Express. July 3, 2015. Accessed August 28, 2017.
10 Hood, Marlowe. "The Secret Life of Dodos, Revealed." Phys Org. August 24, 2017. Accessed: September 1, 2017.
11 Johnson, Bailey. "Brazilian Bikini Wax Making Crab Lice Endangered." CBS News. January 14, 2013. Accessed: September 1, 2017.
12 Khalid, Waleed. "Dinosaur Facts For Kids." Animal Time. Accessed August 28, 2017.
13 Kolbert, Elizabeth. The Sixth Extinction: An Unnatural History. New York: Henry Holt and Company. 2014.
14 "Laws Protecting the Bald Eagle." American Eagle Foundation. April 20, 2015. Accessed August 28, 2017. Updated: January 12, 2024.
15 Levy, Sharon. Once and Future Giants: What Ice Age Extinctions Tell Us About the Fate of Earth’s Largest Animal. Oxford: New York, Oxford Publishing. February 17, 2011.