We take evolution for granted. It is easy to imagine ourselves as the end goal, regardless of whereas there is a God or not. That the current state of affairs is the destined one.
But evolution is nothing if not chaos. Life is the result of many chances and happenstances, which resulted in our status quo. The most frequent “what if” scenario when imagining different possibilities of how life would have evolved different is perhaps the famous “what if [non-avian] dinosaurs never died out”, but I believe this project will illustrate this point even better.
In our timeline, Theria, the group of mammals composed of placentals, marsupials and any extinct cousins that descended from their last common ancestor, came to dominate the world. From the hopping kangaroos to majestic tigers, to the flying foxes and enormous whales, they’re the definition of “mammal” in most people’s minds.
But it wasn’t always like this.
Even today, monotremes still live in Oceania, but the beginning of the “Age of Mammals” actually had another group as far more dominant than therians: multituberculates. This ancient lineage were the most common and diverse mammals in the Mesozoic, and their entrance into the Cenozoic was promising: surviving a mass extinction event, they proliferated and came to dominate the mammalian fossil reccord for the first 5 million years.
But they declined rapidly, for reasons still poorly understood, giving way to therian mammals. This is why you’re here, and why only some paleontologists know what a multituberculate is.
So what if they didn’t die out?
Ectypodus arctos devouring a basal rodent by Dylan Bajda. Already a carnivorous animal, this scene could have taken place in both timelines, but in this one it heralds the end of placentals, and the era of the allotheres.
Table of contents
- What is a multituberculate?
- An alternate history:
- Animal Groups (note: only until Oligocene for now)
- Multituberculate Diets
- Multituberculate Saberteeth
- Multituberculate Sounds
- Flying Mammals
- Sea Mammals
- Marine Reptiles
- A world with no lizards
- Alternate Timelines Of The Timeline
- Nyctosaurid Earth
- Enantiornithean Earth
- The three Multituberculate Earths