The sequence of koalas in the fossil record:
| 15 million years ago: Perikoala Palankarinnica | |
| 10 million years ago: Litokoala Kutjamarpensis | |
| 5 million years ago: Koobor notabilis and Koobor jimbarratti | |
| 0 million years ago: Phastcolarctos cinereus & Phastcolarctos stirtoni |

| Gazette. |
| from the Greek words for "leather pouch" and "bear". Later, the German naturalists Goldfuss gave it the specific name cinereus, meaning "ash colored", after the color of the original specimen. |