Anachronisms in the Book of Mormon 1000 years before the Jaredite record in the Book of Mormon begins. The main point of contention is how late these animals were present in the Americas before becoming extinct. Various Mormon authors have cited evidence that North American mound-builder cultures were familiar with the elephant. The oldest mound-builder societies date to around 2000 BC. The mound builder/elephant controversy did not originate with the Book of Mormon. In "The Mound Builders, Their Works and Relics", author Stephen Dennison Peet cites instances of exhumed mastodon remains and arguments given for why the remains were believed to be contemporary with mound builders.
Manis Mastodon Site tests dated the Manis site at 13,800 years old. Since the 1950s, archaeologists have believed the Clovis people were the first human inhabitants of North America and that they lived here 13,000 years ago. However the discovery of sites pre-dating Clovis, such as Monte Verde in Chile and Meadowcroft Rockshelter in Pennsylvania, have been challenging this presumption at least since the 1990s. The Manis Mastodon Site is 800 years older than the Clovis people. This site, among others, is helping to change the long-held beliefs of many archaeologists about the earliest human inhabitants of North America. The Manis Mastodon Site