https://www.vice.com/en_us/article/wx8ymx/scientists-sequenced-million-year-old-mammoth-dna-the-most-ancient-ever

In a major scientific breakthrough, researchers have sequenced ancient DNA from mammoths preserved in Siberian permafrost that lived more than one million years ago, making it by far the oldest genomic data ever recovered from any specimen. 

DNA extracted from the teeth of two mammoth specimens is hundreds of thousands of years more ancient than the previous record-holder for oldest sequenced DNA, belonging to a horse that lived between 560,000 and 780,000 years ago, according to a study published on Wednesday in Nature.