History Main / MeekMesozoicMammal

The Mesozoic is commonly called "the AgeOfReptiles" because the largest animals at the time (and the largest land animals of ''all'' time) were all reptiles, from non-avian dinosaurs on land, pterosaurs in the sky, and mosasaurs, plesiosaurs, and ichthyosaurs in the water. Around the same time as the first dinosaurs in the late Triassic, the first true mammals evolved, but due to reptiles occupying all the large niches, they rarely reached a metre long.

** ''WesternAnimation/TheLandBeforeTimeIVJourneyThroughTheMists'' plays with this with Tickles, a ratlike mammal. While she is prone to fleeing away from larger animals as the rest of her kind are, she has a moment of bravery when she saves Ducky from being eaten by [[FeatheredFiend Ichy]] and [[NeverSmileAtACrocodile Dil]].

* WesternAnimation/{{Dinotrux}}: Interestingly (in a kinda [[Irony ironic]] way) this trope gets played not by mammals, but ''reptiles''. Reptools are half-lizards and half-tools who live in Reptool Ravine, a [[HiddenElfVillage hidden Reptool village]] where the citizens spend their days hiding in fear of the outside world including titular Dinotrux (half-dinosaurs, half-vehicles).

* While all the vertebrates in ''WebOriginal/HamstersParadise'' are mammals, the original draft features an era called the Mouseozoic that resembles the Mesozoic. The largest animals at the time resemble dinosaurs, but there's a group of small hamster-descendants that have changed little from their ancestors called neomice, that are mostly noctural and low on the food chain. [[spoiler:They're among the few lineages to survive the ice age that ends the Mouseozoic.]]

In RealLife, this trope wasn't the case, as they were quite a diverse and successful group back then, with swimmers, gliders, and burrowers among their ranks. Some of them were so big and fierce that they even ''ate'' small [[https://en.wikipedia.org/wiki/Repenomamus dinosaurs.]][[note]]We're not just talking dinosaur eggs or hatchlings either, adult dinosaurs up to ''two metres long'' may have been on the menu for certain Mesozoic mammals according to recent findings[[/note]] The trope also gets a bit surreal when you consider the predecessor to mammals, the Therapsids, were the dominant land animals of the Permian Period that immediately preceded the Age of Dinosaurs. The Permian ancestors of dinosaurs meanwhile were the small forms occupying niches not unlike what mammals would in the Mesozoic.

In RealLife, this trope wasn't the case, as they were quite a diverse and successful group back then, with swimmers, gliders, and burrowers among their ranks. Some of them were so big and fierce that they even ''ate'' small [[https://en.wikipedia.org/wiki/Repenomamus dinosaurs.]] The trope also gets a bit surreal when you consider the predecessor to mammals, the Therapsids, were the dominant land animals of the Permian Period that immediately preceded the Age of Dinosaurs. The Permian ancestors of dinosaurs meanwhile were the small forms occupying niches not unlike what mammals would in the Mesozoic.

** In "Surprise", Dink befriends a mouse-like mammal named Tiny whose attempts to get fruit is being thwarted by a brutish sauropod keeping the fruit tree to himself. The two team up to deal with the sauropod, with Tiny climbing onto the sauropod's back and covering his eyes with a flower to distract him while Dink ties his tail to the tree.

* ''Series/PrehistoricPlanet'': In the episode "Ice Worlds", an Alaskan troodontid is shown using fire to smoke out a number of small burrowing mammals (identified by WordOfGod as ''Cimolodon''), and it easily captures and kills one of them. This is the only time in the entire series mammals appear.

** In fact, one of the common subsets of this trope by portraying human ancestors in this Mesozoic does have some validity. Molecular research showing when lineages diversified implies that the earliest primitive primates, likely resembling modern tree shrews or mouse lemurs, were probably around in the later stages of the Cretaceous Period.

In RealLife, this trope wasn't the case, as they were quite a diverse and successful group back then, with swimmers, gliders, and burrowers among their ranks. Some of them were so big and fierce that they even ''ate'' small [[https://en.wikipedia.org/wiki/Repenomamus dinosaurs.]] The trope also gets a big surreal when you consider the predecessor to mammals, the Therapsids, were the dominant land animals of the Permian Period that immediately preceded the Age of Dinosaurs. The Permian ancestors of dinosaurs meanwhile were the small forms occupying niches not unlike what mammals would in the Mesozoic.

* Generally speaking this trope has ''some'' truth to it, but this isn't to say mammals were all meek prey species. The End-Permian extinction event was a significant blow to Therapsid [[note]]the family of animals mammals belong to[[/note]] diversity and the following Triassic Period saw Archosaurs [[note]]the family of animals dinosaurs, pterosaurs, and crocodilians belong to[[/note]] largely surpass Therapsids for the megafauna roles by the end of the Period. Archosaurs being more efficient at larger sizes for various reasons meant the predecessors to and even true mammals just couldn't successfully compete with them for ecological niches larger than around badger size. Broadly speaking, mammals actually did manage a respectable diversity in small forms across the Mesozoic which would go on to found the various families we see today after the End-Cretaceous extinction; it's just they didn't start achieving large sizes until after the Mesozoic.

Since MostWritersAreHuman and ReptilesAreAbhorrent, it's easy to sympathise with our distant ancestors. In fiction, non-fiction, and {{Speculative Documentar|y}}ies alike, they're usually portrayed as underdogs whose potential is yet to be unleashed as they cower beneath their [[PrehistoricMonster dinosaur overlords]]. This trope may have risen to popularity in The80s, when HollywoodPrehistory became a DeadHorseTrope coupled with the Dinosaur Renaissance influencing popular culture, establishing dinosaurs as complex and prosperous even today.

In RealLife, this trope wasn't the case, as they were quite a diverse and successful group back then, with swimmers, gliders, and burrowers among their ranks. Some of them were so big and fierce that they even ''ate'' [[https://en.wikipedia.org/wiki/Repenomamus dinosaurs.]]

Since MostWritersAreHuman and ReptilesAreAbhorrent, it's easy to sympathise with our distant ancestors. In fiction, non-fiction, and {{Speculative Documentar|y}}ies alike, they're usually portrayed as underdogs whose potential is yet to be unleashed as they cower beneath their [[PrehistoricMonster dinosaur overlords]]. This trope may have risen to popularity in The80s, when OneMillionBC became a DeadHorseTrope coupled with the Dinosaur Renaissance influencing popular culture, establishing dinosaurs as complex and prosperous even today.

** In the first film, a recently-hatched Ducky briefly chases after a small, shrew-looking mammal.

* ''Literature/TheNewDinosaursAnAlternateEvolution'': It's made clear that the continued dominance of the dinosaurs has prevented any possible diversification of mammals, and they have all remained small and rodent-like. Only one mammal gets any focus, the desman-like zwim, although unnamed mammals appear as generic prey animals in a few other entries.

* ''WesternAnimation/{{Futurama}}'': Discussed in "A Clockwork Origin". The crew gets attacked by robotic versions of dinosaurs and large reptiles, which are then wiped out by a solar flare bring out an electric surge that short-circuited them. The Professor proclaims that "only puny mammal-like robots cowering in caves could survive such a catastrophe", just as Bender comes out of a cave annoucing that he had taught himself to knit during the time.

* ''WesternAnimation/{{Futurama}}'': Discussed in "A Clockwork Origin". The crew gets attacked by robotic dinosaurs and reptiles, which are then wiped out by a solar flare bring out an electric surge that short-circuited them. The Professor proclaims that "only puny mammal-like robots cowering in caves could survive such a catastrophe", just as Bender comes out of a cave annoucing that he had taught himself to knit during the time.

* WesternAnimation/{{Futurama}}'': Discussed in "A Clockwork Origin". The crew gets attacked by robotic dinosaurs and reptiles, which are then wiped out by a solar flare bring out an electric surge that short-circuited them. The Professor proclaims that "only puny mammal-like robots cowering in caves could survive such a catastrophe", just as Bender comes out of a cave annoucing that he had taught himself to knit during the time.

* ''Amime/YouAreUmasou'': During his mad search for Umasou, Heart terrifies a squirrel-looking mammal into [[PottyFailure wetting itself]].

** ''WesternAnimation/TheLandBeforeTimeIVJourneyThroughTheMists'' downplays this with Tickles, a ratlike mammal. While she is prone to fleeing away from larger animals as the rest of her kind are, she has a moment of bravery when she saves Ducky from being eaten by [[FeatheredFiend Ichy]] and [[NeverSmileAtACrocodile Dil]].