Tyra is a female tyrannosaurus rex and the main protagonist of Dino Time.
Tyra was a pink, female Tyrannosaurus Rex, who ruled over the Upper Valley, a massive Cretaceous period valley that would eventually become the town of Terra Dino. Despite being a predatory Tyranosaurus, she was a kind, fair and caring ruler to many of her fellow dinosaurs and looked after many orphan dinosaurs,one of them being Dodger, a hyperactive feathered dinosaur. However, all was not well for Tyra, for her throne was challenged by two Sarcosuchuses, Sarco and Surly who were fed up with their domain in the volcanic tar pit abundant Lower Valley and so,along with their dimwitted henchmen Morris, Borace and Horace, decided to overthrow Tyra and claim rulership over the Upper Valley and recklessly feast upon the other dinos. Luckily, Tyra had managed to keep the diabolical duo at bay.
One day, Tyra had managed to give birth to a child of her own and she eagerly awaited for days for the egg to hatch.
Then something quite unexpected happened. A time machine from present day Terra Dino landed in her nest and caused her real egg to dematerialize and be sent into the future. The unwilling passengers on-board the machine were three kids. Ernie Fitzpatrick,a rebellious daredevil who is an expert on dinosaurs and whose rambunctious behavior has led him to have a difficult relationship with his mother Susan, his little bratish sister Julia who likes to tattle on her brother and get him into trouble (and is partially responsible for activating the time machine and sending them back in time having caused Ernie to spill some soda on the time machine's control panel while trying to ''bust'' him again) and Max Santiago, a child prodigy, Ernie's friend and the son of Dr Santiago, the man who built the time machine. However, due to the time machine's oval shape, Tyra could not tell the difference between it and her egg so when the trio emerged from the machine, Tyra thinks that their her own children and quickly takes them in. She immediately calls all the other dinosaurs in the valley to bear witness to her new children. They congratulate Tyra on the birth of her ''newborn'' sons and daughters and she decrees that when her reign is at a close, they will protect them and the Upper Valley from the evil Sarco Brothers.
Some of the dinosaurs, are skeptical of the "newborn"'s ability to protect them and note their strange appearance as well. Tyra reassures them that her babies will grow up big and strong like her and sends them away, saying that her babies need their nap time. Unbeknownst to them all, Morris, Borace and Horace were spying on her and her ''newborns'' and decide to report back to the Sarco brothers. The kids try to get the time machine up and running again to get back to the present, but unfortunately, the power key which helps power the machine is missing (unbeknownst to Max and Julia, Ernie had hidden it in his pocket so that they could explore some more).
Later, while Tyra is sweeping up her lair with her tail, Ernie tries to go exploring, but Tyra stops him and makes him go back to the nest. Just them, a rustling is heard in some nearby ferns, causing the kids to panic and Tyra to get defensive. However, it turns out to be Dodger, who had heard about Tyra's ''newborns'' and wanted to see them for himself. When he sees them, he is overjoyed to have some new siblings and so he and the kids befriend each other (he too notes their strange appearance however). Later that night, Tyra puts the kids to bed and proclaims her excitement about teaching them everything she knows.
Early in the morning, the kids sneak away from Tyra to look for the power key and after getting into a bunch of shenanigans (in which Ernie actually loses the power key), Tyra finds them and takes them back to the nest. On the way back, she expresses her disappointment in Dodger for not keeping an eye on the kids. She then comes to the conclusion that if their going to start wandering off on their own, she might as well start teaching them everything she knows.
Throughout the rest of day, she gives the kids lessons on how to survive and protect the Upper valley. These lessons include hunting, practicing roaring, gathering fruit and lighting camp fires (one of which she accidentally blows out onto the kids by sneezing).
Later that night, after Tyra puts them to bed again, Ernie tries to sneak away to look for the power key. Unfortunately, Tyra wakes up and catches him in the act. Ernie tries to explain to Tyra that he needs to find the power key and tries to get away. Tyra however, doesn't have any of it, so she decides to "ground" him by sitting on him all night (much to Ernie's embarrassment, especially when the others find out in the morning).
The next day, Tyra and the others find tracks from Morris and his gang. The kids decide to follow the tracks and Tyra decides to go with them, saying it would be good practice for them. While their away, Morris, Borace and Horace steal the time machine on the Sarco brothers orders (who think that its another one of Tyra's eggs and wish to use it as bait to lure Tyra into the Lower Valley). Meanwhile Tyra and the kids follow the tracks down the river to Lower Valley. Tyra, knowing better than to venture any further, forbids the kids from entering the Lower Valley and decides to take them back to the nest. She tells Dodger to keep a closer eye on the kids as she does not want them entering the Lower Valley.
When they get back to the nest, the kids finally find the power key (after it had been eaten by Horace and spat out when they were stealing the time machine) and discover, much to their frustration, that Ernie had been withholding it from them until he lost it during their shenanigans. To further rub salt in the wound, they also discover that their time machine has been stolen. As Julia breaks down into tears over the fact that they now have no way of returning to the present, Tyra sympathizes with her children.
Later, while the kids try to carve a message for their parents on Mystery Rock (a famous landmark in Terra Dino) telling to spill Soda on the time machine for it to work, Morris, Borace and Horace (who had been ordered by the Sarco brothers to kidnap one of Tyra's 'newborns'' after the "egg" fails to lure her to their domain) snatch Julia and take her to the Sarco brothers Lair in the Lower Valley. Tyra and the others immediatly give chase and follow the terrible trio to the Lower Valley.
Tyra enters the Sarco brothers lair and confronts Sarco himself. She and the brothers engage in a long-drawn out battle in which she fiercely fights the diabolical duo to protect both her Julia & Max (who had gotten himself captured while trying to rescue Julia) and her rulership in the Upper Valley, all the while the Sarco brothers continue to taunt her.
Luckily, Ernie makes loud, roaring noises to distract the brothers, giving Tyra the opportunity to knock them out and rescue Max and Julia. However, while trying to find their way out of the lair, they end up back where they started. They meet up with Ernie and Dodger (who had managed to defeat Morris, Borace and Horace by causing them to fall into a tar pit).Unfortunately, they run into the Sarco brothers again and Tyra once again engages them in battle, all while an earthquake occurs, causing the lair to start collapsing. Tyra makes the children leave without her while she fends off the brothers. The kids quickly get into the time machine, but Sarco kicks it into a tar pit and it starts to sink. Meanwhile, Tyra continues to battle the malevolent Sarcosuchuses, but it appears they have the upper hand.
Fortunately, the kids (who had decided to abandon the time machine to help Tyra) rush in and try to help her defeat the Sarcos. Ernie, Dodger and Max distract Surly while Tyra fights Sarco himself. All the while, another earthquake strikes, causing the ground to break and flip up. Ernie uses his rocket powered skateboard to launch Surly into a lava pit, killing him and leaving Sarco lone to fight Tyra.
Enraged over the death of his brother, Sarco tries to kill the kids, but Tyra stops him by grabbing his tail and throwing him into a pillar, causing more of the lair to collapse. Tyra shelters the kids from the falling rubble, badly wounding herself in the process. Thinking that she's dead, Dodger and the kids sadly mourn her. However the mourning is cut short when Sarco emerges from a nearby pile of rubble. Seeing Tyra down, Sarco uses this opportunity to go for another attack. Suddenly Sue and Dr. Santiago (who after much trial and error, had managed to build their own time machine out of Sue's car & had brought with them Tyra's real baby who had hatched in Santiago's lab) arrive in the Lower Valleys, and drive the car right into Sarco, knocking him out again. Sue and Santiago reunite with their children. However, Sarco tries to attack the group again, but Tyra regains her strength and engages Sarco in one last duel to the death. During the battle, Sarco laches onto Tyra's neck and bites down hard. Just when it seems Sarco has the upper hand again, Tyra sees her children in distress and she gains the strength to break free from Sarco's jaws and throws him over the edge of a cliff, at the bottom of which is a tar pit. As Sarco clings onto the edge of the cliff, Tyra sarcascally asks Sarco to let her know if the tar's too hot before breaking the cliff with a stomp, causing him to fall into the tar pit, finally killing the wicked sarcosuchus once and for all. Tyra then lets out a triumphant roar before turning her attention back to the kids. Sue thinks Tyra is hostile and tries to defend the group but Ernie and others tell her that she was the one protected them. Upon seeing Sue and Santiago, Tyra realizes that the kids belong to them and returns them to her, albeit with a heavy heart. To cheer her up, Dr. Santiago returns her real baby. Just then, another earthquake strikes, causing the cave and the entire Lower Valley to fully collapse so Tyra and the others quickly escape and return to the Upper Valley.
As they prepare to leave, the kids say their final goodbyes to Tyra. The group then gets the time machine up and running and they finally return to the present (unknown to them, Dodger had managed to hitch a ride with them). Tyra is also happy to finally have her real baby back and to never worry about the Sarco brothers again.
The end credits show the kids drawing pictures of Tyra and of them hanging out with her, implying that they may have gone back to visit her again.
She is cool, calm, and collected in most situations and is shown to be a proud and loving mother.