Were dinosaurs warm-blooded or cold-blooded?

When the first dinosaur fossils were recognized in the mid-19th century, scientists envisioned that the creatures were basically giant, lumbering lizards. They also presumed that dinosaurs were like present-day, cold-blooded lizards, meaning that their body temperature depended on the surrounding environment. However, this notion was later fiercely debated.  

“The general picture that we have of dinosaur physiology has changed quite a bit through the last [several] decades,” says Jasmina Wiemann, a molecular paleobiologist at the California Institute of Technology….