### id260185274 millipedes were the first oxygen-breathing animals > Millipedes have been around for about [420 million years](https://www.sciencedirect.com/science/article/abs/pii/S1467803909000887). They were the first known animal to breathe atmospheric oxygen, based on fossil evidence. Some extinct species were over 6 feet long and 1 foot wide. - [View Highlight](https://read.readwise.io/read/01fq9jrcehrk98rjem788rcrjv) - [[Scientists Have Identified the First 'True' Millipede by Shayla Love#id260185274 millipedes were the first oxygen-breathing animals|View in Vault]]