usage Extant is sometimes wrongly used simply to say that something exists, without any connotation of survival: plutonium is perhaps the deadliest element in existence (not the deadliest element extant)
1545, "standing out above a surface," from L. extantem, prp. of extare "stand out, be visible, exist," from ex- "out" + stare "to stand," from PIE base *sta- "to stand" (see stet). Sense of "in existence" appeared in Eng. 1561.