Dinosaurs are not a comic book team, rather a classification of animals.
Depiction in Fiction
Dinosaur fossils have been found by human civilizations since the dawn of our own history, but their scientific explanation baffled their discoverers until the modern day. The fossils had previously used to prove the existence of numerous mythical creatures including dragons. Near the beginning of the twentieth century, the first scientific hypotheses were put forward which have formed the basis of those of the modern day. However, the hypotheses have evolved over time. With the advent of comic books in the early part of the 20th century, the subject of dinosaurs provided a fertile one for the telling of adventures (the earliest comics generally told adventure stories before superheroes were introduced.) With only a rough understanding of the science, early writers began to incorporate them into their stories. Two types of stories persisted, those of creatures that had traveled through time, or those of ancient humans that encountered them. The interaction of humans and dinosaurs is obviously not possible and an anachronism with dinosaurs having been dominant on Earth tens of millions of years ago, while humans have existed in their modern state since approximately 100,000 years. With the gradual creeping in of science into the field of comics (especially true with the beginning of the silver age in the 1960s), the human interaction with dinosaurs was changed to generally those dinosaurs that had survived the global cataclysm which had destroyed them. Thus areas such as Dinosaur Island became possible as a location out of space and time (such concepts of dinosaurs did occur earlier, such as in Arthur Conan Doyle's Lost World.) the only major change to the depiction of dinosaurs in comics (and in pop culture) has been with the popularity of Jurassic Park. In these stories scientists have discovered dinosaur DNA in fossilized amber and after extracting it were able to clone living animals from it. This is a very specific concept though and doesn't generally affect the depiction of the animals overall.
Dinosaurs exhibited a wide range of sizes, from creatures similar in size to the smallest land mammals to large behemoths which were the largest creatures to ever inhabit the earth's landmass (though some sea creatures are larger.) Because of their large size and imposing appearance numerous species became more common in fiction than others among them the Tyrannosaurus rex, the Brachiasaurus (Brontosaurus), Triceratops, and the Stegosaurus. The flying dinosaurs, the Pterodactyls have also been popular due to their ability to fly. Since the release Jurassic Park, the Velociraptor has been popular due to its supposed intelligence, speed and ferocity.
Dinosaurs in the Marvel Universe have been seen in the Savage Land. A tropical jungle infested with a variety of prehistoric life forms including primal humans but also dinosaurs. There are dinosaur characters like Devil Dinosaur, and characters with dinosaur based powers such as Reptil.
Famous examples of dinosaurs in DC are Dinosaur Island and those found in Skartaris.
Turok often interacts with dinosaurs in the course of his adventures.
Dinosaurs have been the genetic creation of Ingen in which their DNA was discovered and through DNA mixing with other species of animals (in this case toads) gave them life and were to be used as attractions at Jurassic Park. However the attraction didn't go as planned and the dinosaurs escaped and went on a murderous rampage. Despite being wildly popular in modern culture, Jurassic Park has never been particularly popular in comics.