... but, I do have a few ideas for a strictly land before time fanfiction story with no science fiction, magic, or humans at all.
1. Bron's heard and the old ones's (Ali's) herd meet up and migrate to the great valley together. Complications ensue when Bron (whose wife is dead) marries (or mates with?) Ali's mother (whose husband is either dead or unseen.) When they reach the great valley, everyones relationship to each other is revealed. More complications ensue.
2. Petrie's father arrives in the great valley, and learns that he has children (how many are there?)
Petrie wonders where his father was all this time (like LBT ten, I know.) After a long story, more complications ensue (such as Pterano returning, or yet another natural disaster.)
3. Tria lays eggs! (enough said)
These are just some of the feasable, non-science fiction ideas that are strictly related to the series.