Warm-bloodedness possibly much older than previously thought: Characteristic may have developed 20 million years earlier, study shows

This is really huge. The reason isn’t just that Ophiacodon may have been warm blooded. It’s that it puts warm bloodedness that much closer to the origin of Reptiles. It may have been a common trait in the early Reptiles from which Ophiacodon arose. The Reptiles we see now may have later lost the ability to generate their own heat.