Dr. Cretacia, biological mother of Rex Owen and wife of Dr. Ancient, has short blonde hair, wears glasses, and sports a distinctive outfit: a pink suit with white cuffs and a blue vest. Her name originates from the Cretaceous period.

Outgoing and occasionally silly, her personality contrasts with her husband's reserved nature. She displays genuine affection for her family, especially her son Rex.

A significant scientific partner to Dr. Ancient, she co-discovered the Stone Tablets in the future and co-created the Backlander time machine to rescue dinosaurs as cards. Unaware of her pregnancy during this project, she traveled with Dr. Ancient to the past, where Rex was born. On a return trip to the future, the Alpha Gang (Dr. Z and Seth) sabotaged their mission, ejecting their escape pods into a time vortex. This separated Rex from his parents; Dr. Owen later found the infant.

Retrieved from the vortex in the first series finale, she reunited with Rex. She and Dr. Ancient attempted to return Rex and the dinosaur cards to their original timeline, but an attack by the Spectral Space Pirates interrupted this.

Captured by the Spectral Space Pirates alongside the Taylors and Drakes during the second series, she was held aboard their ship. Coerced into building a Cosmos Stone Detector with Dr. Ancient, they subtly sabotaged the project. After rejecting an exchange involving the Cosmos Stones, they were rescued when the D-Team's Backlander docked with the Pirate vessel during the final confrontation. Following the Backlander's disablement, she returned to the future using the Pirates' ship.

Her narrative involvement centers on group dynamics with her husband or the collective of captured parents. Rex inherited her blonde hair.