History TearJerker / PrehistoricPlanet

** The peril the pregnant mother pleisiosaur goes through as she gives birth and her adolescent son's frantic and dangerous attempt to distract the mosasaur. Fortunately, it turns out well for them in the end.

** While the blow is softened somewhat by the knowledge that he lived a full life, the death by old age of the 70-year-old bull ''Alamosaurus'' is still a sombre event.

** The hatchling ''Isisaurus'' who falls into a volcanic mud-trap and desperately cries out to its siblings, [[NoSympathy who completely ignore it and continue on their way]]. We're mercifully spared the shot of its death, but its fate is clearly implied. Made even worse in that, while this series is ''no'' stranger to averting ImprobableInfantSurvival, the majority of the other infant animals up to this point have at least been lucky enough to receive relatively quick and painless deaths. [[CruelAndUnusualDeath We can safely assume this hatchling's death was neither]].

** The hatchling ''Isisaurus'' who falls into a volcanic mud-trap and desperately cries out to its siblings, [[NoSympathy who completely ignore it and continue on their way]]. We're mercifully spared the shot of its death, but its fate is clearly implied. Made even worse in that, while this series is ''no'' stranger to averting ImprobableInfantSurvival, the majority of the other infant animals up to this point have at least been lucky enough to receive relatively quick and painless deaths. [[CruelAndUnusualDeath We can safely assume this hatchling's death was neither]].

** The hatchling ''Isisaurus'' who falls into a volcanic mud-trap and desperately cries out to its siblings, [[NoSympathy who completely ignore it and continue on their way]]. We're mercifully spared the shot of its death, but its fate is clearly implied. Made even worse in that, while this series is ''no'' stranger to averting ImprobableInfantSurvival, the majority of the other infant animals up to this point have at least gotten quick and relatively painless deaths. [[CruelAndUnusualDeath We can safely assume this hatchling's death was neither]].

** The male ''Carnotaurus'' goes through all the trouble preparing to woo a mate and performing his courtship dance, but at the end, the female isn't interested and departs leaving him empty-handed.

[[quoteright:350:https://static.tvtropes.org/pmwiki/pub/images/screenshot_20220529_172601_youtube.jpg]]
[[caption-width-right:350:[[DidNotGetTheGirl It's alright, buddy. You tried your best.]]]]

** The ''Dreadnoughtus'' dying from their injuries due to fighting over mates. They are simply so big and heavy that merely falling down in a fight is a death sentence, as they are too heavy to get up again. The kicker is the AstronomicZoom that shows just how even as giants they're dwarfed by the land the live in.

** Two male ''Barbaridactylus'' are shown fighting in mid-air over the rights to engage in courtship displays on a large flat rock surface. The dominant male manages to kill his rival by landing a hit, which causes it to slam into a rock wall and due to its flight momentum violently crashes on the sandy slopes below.

** When the ''Pachyrhinosaurus'' herd breaks, the previously-wounded bull starts to lag behind and gets surrounded by the ''Nanuqsaurus'' pack. While two other males try to come back to help, they are too late as the bull gets taken down with barely a fight.

** The troodontids killing the Artic mammal (likely ''Schowalteria''). It's depressing seeing a cute, harmless, chubby creature running for its life from a fire only to end as the meal of the perpetrator.

** When the ''Pachyrhinosaurus'' herd breaks, the previously-wounded bull starts to lag behind and gets surrounded by the ''Nanuqsaurus'' pack. While two other males try to come back to help, they are too late as the bull gets taken down with barely a fight.

** The troodontids killing the Artic mammal (likely ''Schowalteria''). It's depressing seeing a cute, harmless, chubby creature running for its life of a fire only to end as the meal of the perpetrator.

** Troodontids killing the ''Schowalteria''. It is depressing the only apparence of Mesozoic mammals in the entire show is just fodder, especially an animal that stands out for its unique adaptations for herbivory and massive size.

** The death of one of the baby ''T. rexes'' courtesy of a mosasaur. The father doesn't even seem to notice, and simply carries on with his four remaining chicks.

** Troodontids killing the ''Schowalteria''. It is depressing the only apparence of Mesozoic mammals in the entire show is just fodder, especially an animal that stands out for its unique adaptations for herbivory and massive size.

** Similarly, the mother ''Masiakasaurus'' losing one of her babies to a hungry ''Beelzebufo''.

** Two male ''Barbaridactylus'' are shown fighting in mid-air over the rights to engage in courtship displays on a large flat rock surface. The dominant male manages to kill his rival by landing a hit, which causes it to slam into a rock wall and due to its flight momentum violently crashes on the sandy slopes below.

** The ''Alcione'' hatchlings’ perilous journey to the forest, where several get eaten by larger pterosaurs, by ''Barbaridactylus''in the air and by ''Phosphatodraco'' on the ground. A lucky few, however, safely reach the refuge of the forest.