| Named By: | Christian Erich Hermann von Meyer in 1852 |
| Time Period: | Middle Triassic, 245-228 Ma |
| Location: | Europe, Middle East and China |
| Size: | 6 meters long |
| Diet: | unavailable |
| Fossil(s): | Several Skeletons, many preserved juveniles from Besano Formationin in Italy |
| Classification: | | Chordata | Reptilia | Diapsida | Archosauromorpha | Prolacertiformes | Tanystrophidae | |
| Also known as: | | Tribelesodon | Procerosaurus | |
Tanystropheus (Greek tanus "long" + strophaeus "vertebra"), was a 6 metre (20 ft) long reptile that dated from the Middle Triassic period. It is recognizable by its extremely elongated neck, which measured 3 metres (10 ft) long - longer than its body and tail combined. The neck was composed of 12-13 extremely elongate vertebrae Fossils have been found in Europe, the Middle East and China. Complete skeletons of juvenile individuals are most abundant in the Besano Formation of Italy, dating to 232 million years ago during the middle Triassic period (Ladinian stage).