Topps, Cera's belligerent father, and his first wife are seen to have several children in the first film. However, when he and Cera are reunited in the Great Valley at the end of the film, his wife and all of Cera's siblings are absent. This suggests that they died on the herds' journey to the Great Valley. Still, the existence of Dinah and Dana - Cera's niece and nephew and Topps's grandchildren - implies that at least one of Cera's older siblings survived to adulthood. Topps's family's fate thereof remains unknown.
Dinah and Dana having only appeared in The Secret of Saurus Rock also implies that this older sibling of Cera's and his/her nuclear family live outside the Great Valley, and occasionally visit their relatives within.
Cera is seen to have nestmate siblings at her hatching; they seem to be mostly sisters, according to Cera: Littlefoot (trying to persuade Cera to come with him): "Well at least we wouldn't be alone!" Cera: "Well, when I find my sisters, I won't be alone!". They, along with their mother, have mostly disappeared from the film series, and it is disputed as to what exactly happened to them. Their possible fates are:
- Because of the fatalistic nature of the original film, they and their mother may have died on their way to the Great Valley; possibly from from hunger, thirst, exhaustion, or being attacked by Sharpteeth.
- It is revealed in The Stone of Cold Fire that Pterano, Petrie's uncle, manipulated a large portion of the herd into breaking away and following him instead of Topps and Grandpa Longneck. After a while, they were attacked by Fast Biters, and presumably most if not all of them were eaten or killed. Cera's mother and her siblings may have been among these ill-fated dinosaurs as, what appear to be Triceratops are seen with a number of unknown dinosaurs.
- Cera's mother may have, for whatever reason, divorced Topps and taken custody of all the children except Cera. This theory would lead to the questioning of why they seem to have left the Great Valley, since the Great Valley had everything that all the plant eaters could possibly need.
Two of Cera's sisters may appear in The Great Valley Adventure and The Land Before Time III: Time of the Great Giving; in which two baby Threehorns, colored same as Cera, are seen playing near Topps in the pool beneath the Thundering Falls. It is not made clear if these are Cera's younger sisters, nephews and/or nieces, cousins, or unrelated Threehorns that are in the valley.
Baby Threehorns seen in first two sequelsEdit
The death theory is heavily disputed by the end scene (the Peaceful Valley-reprise) of The Great Valley Adventure, in which, along with Ducky's younger siblings hatching, three or four little Threehorns run up behind Cera and grab her in play. Two Threehorns identical to these also appear in The Time of the Great Giving when Littlefoot is at the Thundering Falls. This could suggest that Cera's mother does make it to the Valley alive and has more children with Topps before her definate disappearance. However, it is still fully possible that these little Threehorns are completely unrelated to Cera. It is nearly impossible to draw any conclusions about the fate of Cera's family, as the early sequels are not clear on this.
Main Article: Tricia
Tricia is a young dark pink Triceratops. She is the daughter of Tria and Topps and the paternal half-sister of Cera. Her first appearance is in The Land Before Time XII: The Great Day of the Flyers.