Prehistoric Animal Sizes

Mammals

Heaviest prehistoric mammals

A list of prehistoric mammals over 10 metric tonnes.

1. Basilosaurus (38.6-?60.2 tonnes/ 40-60.8 tons)
2. Basiloterus (30-?40 tonnes/31-?40 tons)
3. Indricotherium (12-15 tonnes/12-16 tons)
4. Deinotherium (10-14 tonnes/10-15 tons)
5. Mammuthus imperator (12.5 tonnes/13 tons)

Longest prehistoric mammals

A list of all prehistoric mammals equal to or longer than 8 metres.

1. Basilosaurus (18-21 metres/59.1-?70.8 feet)
2. Zueglodon (12.3-17 metres/40-55 feet)
3. Basiloterus (10-?13 metres/33-?42.6 feet)
4. Deinotherium (8.8-12.5 metres/29-41 feet)
5. Indricotherium (9-12 metres/30.8-39.3 feet)
6. Zygorhiza (6-8 metres/19.6-25 feet)

Icthyosaurs

Longest Icthyosaurs

A list of all icthyosaurs equal to or longer than 9 metres.

1. Shonisaurus (18-23 metres/59-75 feet)
2. Himalayasaurus (14.3 metres/46.9 feet)
3. Temnodontosaurus (13.4 metres/44 feet)
4. Cymbospondylus (10-11.6 metres/33-38 feet)

Smallest Icthyosaurs

A list of all icthyosaurs under 3 metres.

1. Chaohusaurus(60 centimetres/2 feet)
2. Mixosaurus (1.1 metres/3.8 feet)
3. Eurhinosaurus (1.5 metres/4.7 feet)

Plesiosaurs

Longest Plesiosaurs

A list of all plesiosaurs equal to or longer than 9 metres.

1. Elasmosaurus (15 meters/49 feet)