A DNA molecule is very long, it has of the order of 1 billion nucleotides. You don’t need entire molecules to do the sequencing, just segments. Even if you had

A DNA molecule is very long, it has of the order of 1 billion nucleotides. You don’t need entire molecules to do the sequencing, just segments. Even if you had the entire molecules, you would start by splitting them up [1]. If you can retrieve enough segments, you might try some sort of Bayesian inference. You start with the DNA of the common ancestor of reptiles and dinosaurs (and therefore birds). You don’t know what it was, but you know that it evolved into the current reptiles and birds via random mutations followed by adaptive selections. You get a posterior for it, then you use it as a prior for the DNA of the dino for which you have sequenced a number of segments. [1] https://www.khanacademy.org/science/ap-biology/gene-expression-and-regulation/biotechnology/a/dna-sequencing https://www.khanacademy.org/science/ap-biology/gene-expressi...