Warm Blood Crocodiles? The Endothermic Ancestry of Crocodilians. Part 2: Evolutionary History

Like most other reptiles, crocodilians have a low metabolism. Commonly referred to as “cold-blooded”, they are reliant on the external environment to maintain their body temperature. Among other things, this means they are not able to be as active as warm-blooded animals, who generate their own body heat. However, this was not always the case. Like their more famous cousins, the dinosaurs, the ancestors of the crocodilians were also once warm-blooded. While Part 1 examined the evidence for this, this video will instead explore how the metabolism of the ancestors of the crocodilians changed over time and why they returned to a lower metabolism.

Sources

https://www.sciencedirect.com/science...

https://digital.library.adelaide.edu....

https://academic.oup.com/bioscience/a...

https://academic.oup.com/biolinnean/a...

https://royalsocietypublishing.org/do...

https://academic.oup.com/sysbio/artic...

https://onlinelibrary.wiley.com/doi/1...

00:00 - Introduction
01:38 - Distant Relatives
02:58 - Triassic Period
05:09 - Jurassic and Cretaceous Periods
06:46 - Metriorhynchidae
07:38 - Cenozoic Era
08:16 - Endothermy vs. Ectothermy
09:53 - Ectothermy and the Crocodilians
11:22 - Convergent Ectotherms
12:37 - Early Loss of a High Metabolism
13:40 - Implications
15:52 - Outro