In school, my child is being challenged of how dinosaurs fit into science. How can I provide her proof? Shouldn't we just have faith that they were part of God's original creation?
There is nothing significant nor special about ‘dinosaurs’. They are merely extinct animals, no different than a carrier pigeon or dodo bird. They lived on earth in times past and today we occasionally find their skeletal remains. Beyond that, you are correct that dinosaurs are simply some of the animals that God created on Days 5 and 6 in Creation.
The only reason the world assigns so much significance to the discovery of these extinct animals is because they believe (wrongly) that these animals lived millions of years ago, which adds to their mystic. In reality, these animals were just like any other animal that God created at the same time in the Garden of Eden. Many died about 4,500 years ago when the world was flooded with water and at least two of every kind of animal would have been on the Ark with Noah and his family. The animals we call ‘Dinosaurs’ likely became extinct for various reasons after the flood such as the changing post flood climate and being hunted because they were dangerous and/or a food source.
The very existence of millions of fossils buried in layers in the ground lends credibility to scripture as the flood is the most plausible explanation for why there are so many fossilized remains. Fossilization isn't something that just happens, it requires rapid burial under watery conditions which doesn't happen all too often in today's natural processes. Usually when something dies its body gets scattered by scavengers, be it under the sea or on land, and it very rarely gets buried. However, scientifically speaking, we have excellently preserved fossil remains of virtually all of the dinosaurs and every other creature that continues to exist today – and not in small isolated numbers either. This suggests a catastrophic global level of flooding which is naturalistically unexplainable apart from Noah's Flood in the Bible.
For more information on this topic, please read the following:
How do dinosaurs fit into the bible?
You may also find this (older) presentation on Evolution interesting:
Evolution Exposed
Additonally, there are groups such as Creation Ministries International and Answers in Genesis who specialise in the area of Creation Science and actively pursue scientific research with a biblical mindset as well as publishing great resources for kids about Dinosaurs and The Flood.
