65 million years after they ruled the planet, dinosaurs are back.

A new four-part miniseries on the Discovery Channel peels back the millennia and the skin, revealing a never before seen look at the birth and death of dinosaurs.

Researchers have made incredible leaps in the last year or two, learning previously unknown details about how the giant creatures were born, smelled, thought, acted and more. This Sunday at 8 p.m., a new series captures those advances like never before.

"Dinosaur science really evolves on an annular basis. So much changes year after year," explains "Clash of the Dinosaurs" executive producer Bill Howard to FoxNews.com in an exclusive interview.

"The series sets out to gather the sum total of today's paleontology and scientific knowledge about dinosaurs, letting viewers see what these creatures were like as animals, not prehistoric monsters."

SLIDESHOW: A sneak peek at "Clash of the Dinosaurs"

There have also been mighty steps forward in computational power and computer-rendering ability. Discovery's artists used these advances in graphics to depict dinosaurs as never before, letting viewers to see deep inside the body of a dinosaur.

"We took apart the anatomy of the different dinosaurs themselves, and really got into the cutting edge of how they moved, appeared, and behaved," said Howard. To study the muscles, tissues, and brain functions of creatures dead for tens of millions of years, Discovery relied upon the expertise of consulting anatomists and paleontologists, giving a previously unexplored look at dinosaur tendons and tissue.

"We're starting to understand where muscle attached to bone, how skin looked, how it resembled (or didn't) modern animals," said Howard."We've taken walk cycle models and anatomy and put it together with the correct weight and mass and how the muscles would have to move in order to move the joints and so on. With photo-realistic computer graphics, you see what the animals would have looked like when they moved."

"When you see the animals move, you see the skin responding to their movements, the effects of rain hitting their hides," he gushes.

Beyond mere anatomy, the show explores new theories about these powerful animals. For example, conventional wisdom holds that the fearsome Tyrannosaurus rex had a brain like a walnut, limiting its actions to reactions, fight or flight mechanisms. But modern science suggests the T. rex had a large brain capable of complex behaviors. The show depicts the incredibly maternal instincts and family bonding scientists now think was commonplace among the gigantic animals.

Flying reptile Quetzalcoatlus (named after the Aztec god) had a 40-foot wingspan. "We figured out how it's anatomy worked and how it was able to fly for extended periods," adds Howard. Given the creature's weight and size, paleontologists speculated that it lived in an area where it took off from cliffs and soared like a glider. "We've discovered that their leg muscles had the quick reflexes of a frog, so unlike a modern bird, it could leap into the air very readily." Howard also notes that the creatures had tremendous eyesight, seeing in ultraviolet to following the urine trails of its prey.

"These creatures are no longer mysterious, they're more closely related in how they see, think and move to modern animals than you might think."