Horizon Season 1976 Episode 25 The Hot-Blooded Dinosaurs

The Hot-Blooded Dinosaurs is the twenty-fifth episode of the season 1976 of the popular British science television series, Horizon. The show explores the fascinating world of dinosaurs, their unique characteristics and their evolution.

The episode begins by discussing the traditional view of dinosaurs as ancient cold-blooded reptiles. However, recent research shows that some dinosaurs may have been warm-blooded, which is a revolutionary and controversial idea. The scientist leading this research is Robert Bakker, a paleontologist who believes that some dinosaurs were endothermic, or warm-blooded. Bakker posits that some dinosaurs were active creatures who required a high metabolism, but living in a cold-blooded body would have forced them to be sluggish.

Horizon delves deeper into Bakker's research through exploring the fossils that prove warm-bloodedness in dinosaurs. The first example comes from the herbivorous dinosaur named Hadrosaur, which had a massive nasal cavity that was almost the size of a human body's chest. Bakker believes it was used as a way to warm the air before it entered the body, in effect creating something akin to a bird's heat exchange system. The second example comes from the famous dinosaur Tyranosaurus Rex, whose huge size and active nature give the clue to its high internal temperature. Bakker argues that the T-Rex would have to consume a vast amount of prey to generate the energy needed to power such a large body, an impossible feat with a cold-blooded metabolism.

Horizon also explores the possibilities of how dinosaurs could have been warm-blooded. One idea is that they had a unique "gizzard system," allowing them to extract heat from their food. However, it is unclear if this would have been sufficient for warming the body of these enormous animals. Another theory is that these animals possessed a very complicated lung system - possibly even a system similar to some bird species today, like geese or ducks. By storing large amounts of air in their lungs and circulating it in and out of their body, the dinosaurs could have maintained their high internal temperature, effectively acting as their own heating system.

Finally, Horizon discusses the implications of warm-blooded dinosaurs and their connection to the rise of mammals. Although the idea of warm-blooded dinosaurs may seem small, it has a huge impact on how we understand animal evolution throughout history. If some dinosaurs were indeed warm-blooded, it could answer some longstanding questions about how mammals came to be. Mammals could have risen to dominance after the end of the age of dinosaurs, encouraged by the absence of these fierce, warm-blooded giants.

Overall, The Hot-Blooded Dinosaurs is a fascinating episode of Horizon that provides viewers with groundbreaking information about dinosaurs. The program is well researched, engaging, and thought-provoking. It introduces us to new ideas and challenges our preconceptions of what we know about the extinct creatures. It will leave viewers with a greater appreciation for the power and complexity of these magnificent animals.