Top Ten Weirdest Prehistoric Creatures

[Arul]

Cucumber fish, in indonesia we called it teripang. It lived since prehistoric era the fossil found a lot in my country. It eat and poo with the same hole, it only have one hole on it body

[Rathalosaurus]

Okay, Nictosaurus, Ambulocetus and........


TAPEJARA:


For me, these are the most weirdest things that ever lived on earth.

[Tyto_Theropod]

I'm pretty sure that there's so much I'm not including simply because I don't know about it, but I'm going to mainly stick to dinosaurs (excluding the ones people have already mentioned) simply because they're the ones I know most about. I'm not even going to attempt to try and rank these.

Charnia: It grew fractally, nuff said. Common enough in the Precambrian, but pretty weird for us, looking back on it today.
Lambeosaurus lambei: Pretty standard Hadrosaur, and then you get the the crest...
Ankylosaurs: Not as weird as some of the others, but they get a mention for all the armour and spikes, and especially the scary looking tail clubs.
Thylacosmilus: I seriously cannot believe no one has mentioned this guy yet!
Yi qi: Need I say more?
Spinosaurus: A dinosaur on its way to being a whale/crocodile/marinething. This is an aquatic Theropod with tiny hind legs (it was possibly quadrupedal at least some of the time), a crocodile's head, and ginormous neural processes coming off the vertebrae (function still unclear, btw). Dinosaurs don't get much weirder than that.

Probably the weirdest extant animals are deep sea fish. They either look scary, or as if Mother Nature is on acid. Or both.

[Derek.McManus]

 :)Mother Nature on acid...now there's a thought!

[Tyto_Theropod]

If it happened, we'd get Luis V. Rey paintings in real life! 

[Stuckasaurus (Dino Dad Reviews)]

I found this weirdo in the book "Paleo Sharks: Survival of the Strangest". Technically not a shark, though Promexyele is in the ratfish/ray/shark cartilaginous fish family. It apparently was not any sort of "flying fish", but just had really big fins like a lionfish.
That book really does live up to its name, btw. I could probably add several more fish to the list just from there!

[Lizerd]

I think we are forgetting the weirdest creature of all, the almighty ambulocetus. It just doesn't feel right...

[Papi-Anon]

I'd say the weirdest animals are all hominins. Name me one creature in nature outside of hominins that required some form of clothing, fire, and tools to just get by?

But outside of our family tree, here's my list:

Opabinia - prehensile proboscis, five eyes, backwards-facing mouth, and external gill appendages? Are we sure this wasn't something from another planet that got off at the wrong stop?

Thylocosmilus - sabertoothed synapsids are nothing new, but having a sabettoothed CHIN is beyond bizarre.

Deinotherium - having a saber-tusked chin is also weird, but so were a lot of proboscids.

Megatherium - why any sloth would want to give up the easy life of just hanging around chilling to be a more active creature with more worries and on the ground is beyond me.

Gastornis - descended from carnivorous Mesozoic theropods and one of the largest terrestrial animals of its time, it decided to just be a vegan instead of becoming the new T-Rex. Then again it was related to chickens and ducks...

Ambulocetus - "They said I could be whatever I wanted to be when I evolved. So I decided to be a crocodile."

[Brontozaurus]

I'd like to add Mastodonsaurus and Microposaurus to the list, for the fact that they evolved huge fangs in their lower jaw and specialised openings that they fit through in the upper jaw, so that they had the most metal nose piercings of all time.