Aalenian
![Life restorations of two different ammonite genera.](/Images/godic/202412/16/Douvilleiceras_Hoplites3804.jpg")
![Belemnites.](/Images/godic/202412/16/BelemniteDB23804.jpg")
The Aalenian (pronunciation: /ɑːˈliːniən/) is a subdivision of the Middle Jurassic epoch/series of the geologic timescale that extends from about 174.1 Ma to about 170.3 Ma (million years ago). It was preceded by the Toarcian and succeeded by the Bajocian.