Nation It’s tiny, delicate and rare. Zoo hatches a critically endangered northern spider tortoise. June 28, 2023Brittany Truong, USA TODAY NETWORKComments Off on It’s tiny, delicate and rare. Zoo hatches a critically endangered northern spider tortoise. Eggs of the critically endangered northern spider tortoise incubate for 220-240 days and only 1 of 10,000 live to adulthood.