Introduction
Dinosaurs lived on our planet 245 to 65 million years ago. These creatures varied drastically from the 2-metre-long velociraptor to the 25-metre-long brachiosaurus, the plant-eating triceratops to the carnivorous T-rex and the long-clawed therizinosaurus to the armored ankylosaurus. However, the great dinosaur empire perished roughly 65 million years ago when an asteroid hit, trapping the planet in a sphere of ash, cold and death.
But what if they returned? What if mankind developed the technology to bring the dinosaurs back? Should we?
Advantages and Disadvantages
Bringing dinosaurs back would fill in major mysteries about their behaviour and appearance. Also, these creatures may have adaptations that we could use to create new medical treatments. Similar to Jurassic Park, zoos may be created for dinosaurs or dinosaurs may join existing zoos. This would result in zoos attracting more visitors and gaining more money. The existence of dinosaurs could also be an advantage for farms, with dinosaur dung being used for fertilizer and herbivores possibly towing plows.
However, the return of dinosaurs would be a double-edged sword. Dinosaurs may be aggressive towards vehicles, seeing them as a threat or (in the case of carnivores) prey. Some dinosaurs have massive appetites with brachiosaurus needing to eat 400 kg daily and Tyrannosaurus rex requiring 254 kg. This could result in a massive decrease in crops and livestock. However, large carnivores would most likely go for large herbivore dinosaurs instead of loads of cattle or people. Also, some countries may decide to turn dinosaurs into weapons and use them in wars.
The Natural World
If the plant-eating dinosaurs lived in the wild, they would probably live in coniferous forests which have similar plant life to that of the Mesozoic Era. However, it is most likely that dinosaurs would adapt to eat more modern plant life. Also, there is a possibility that the large sauropods may struggle to find enough food. If they managed to survive, the large sauropods may become smaller so they don’t need to consume as much plant matter.
The large sauropods would most likely not gain any predators from the modern world. These dinosaurs are much larger than giraffes, which have few predators due to their size. Meanwhile, ceratopsians (like triceratops), would rarely be hunted, similar to rhinos. The same goes for ankylosaurs due to the armour and tail. However, the smallest herbivores would probably be regularly hunted by animals like hyenas and leopards.
Meanwhile, the carnivorous dinosaurs would have a different effect on the natural world. Large theropods like Tyrannosaurus rex and giganotosaurus would most likely hunt plant-eating dinosaurs. They may also hunt large modern-day animals like elephants and giraffes. Smaller carnivores may hunt the same prey as lions and other big cats. The piscivores (spinosaurus, baryonyx, etc.) would probably live near rivers, lakes and the sea in order to have access to fish. However, all these carnivores would most likely scavenge if given the chance.
Threats
However, dinosaurs would have to face prehistoric and modern problems. The first of these is the environment. The temperatures during the Mesozoic were higher than they are today and dinosaurs may struggle in the colder temperatures. Also, the ancient animals may struggle to find food (depending on size). Only the largest herbivores would probably struggle with ankylosaurus eating approximately 60 kg per day, modern elephants eating up to 150 kg daily and brachiosaurus needing 400kg. The same would probably be true for carnivores. However, if enough large herbivores were brought back and successfully survived and bred, the large carnivores would have a good food supply that did not require multiple kills. Also, dinosaurs may have no or little immunity to modern diseases.
The second major problem for dinosaurs would be us. Just like all other animals, dinosaurs may struggle to adapt to the climate change caused by the pollution from our activities. Also, deforestation would be a major threat due to some of the herbivores needing lots of leaves. Some dinosaurs may also get trapped or injured by our litter. Another alarming threat could be illegal hunting: they could be sold as pets or their scales, bones, claws and teeth may be sold for money.
My Thoughts
I would personally be on the side against bringing dinosaurs back and not keeping them in zoos or sanctuaries. However, this is not because of the threats dinosaurs give to humanity. If we brought them back and released them into the wild, it could be a repeat of 65 million years ago: extinction. The causes would be different; illegal hunting and deforestation instead of a meteor and fire, plastic replacing a sphere of ash. However, the result would be the same. I am not worried about what dinosaurs would do to us but what we would do to them. I am not saying that humanity is evil, but too many creatures are extinct (like the dodo) or critically endangered (like amur leopards) because of us for us to resurrect an ancient species.