An archaeological party explore some caverns underground. Dr. Campbell and Dr. Hughes are the two leaders of the archaeological expedition, and get separated. While Dr. Hughes finds an alien corpse with a fossilized diamond, Dr. Campbell finds hieroglyphics at the cost of the party except for Hughes and himself. Two years later, Campbell and his assistant Holly are digging up the bones of Yonggary, a gargantuan dinosaur 50 times the size of a Tyrannosaurus Rex. Out of nowhere, people slowly are being killed around the site. While Holly is working, Dr. Hughes, who has been legally dead for 2 years, goes to Holly and tells her to stop the dig. Dr. Campbell comes into the tent and sends Dr. Hughes off. Holly quits the expedition when another "Accident" occurs. In the town bar, Dr. Hughes finds Holly and takes her back to her Hotel room to tell her why he thinks the bones of the Dinosaur, which he calls Yonggary, are going to bring the end of the world. After explaining, Holly and Hughes go to the site to stop Campbell but it is too late and Aliens resurrect Yonggary. After Yonggary's first appearance, the Army comes in and takes Holly and Campbell to an army base when Yonggary is dispatched by the aliens again. The army sends choppers after Yonggary, but he destroys them. Yonggary is then sent to the city (which was thought to be New York by fans, but is actually an all CGI Los Angeles near Korea Town) and does some damage, where some jets attack him. Then Yonggary is transported to a power plant where he is attacked by rocket pack soldiers. During the fight, Hughes and Holly find out that the diamond on Yonggary's forehead is the device giving the aliens control of Yonggary. Yonggary is transported back into the city, where the remainder of the soldiers destroy the diamond on his head. Enraged, the aliens send down their own monster, Cycor. Yonggary and Cycor battle, with Yonggary winning. The following morning, Yonggary went to sleep and sent to an uninhabited island where Yonggary can adjust to normal life and become a hero.
A group of young people get lost in an underground cavern while exploring a volcano. Eventually they find their way to the lost city of Atlantis, at the center of the Earth.
In an alternate futuristic society where humans and anthropomorphic dinosaurs co-exist, a tough police detective named Katie Coltraine (Whoopi Goldberg) is paired with a Tyrannosaurus named Theodore Rex (George Newbern) to find the killer of dinosaurs and other prehistoric animals leading them to a ruthless billionaire bent on killing off mankind by creating a new ice age.
The film centers on a group of Navy SEALs, led by American Dr. Frank Reno (Michael Gross), who once worked on the Philadelphia Experiment. The film begins in 1998, when Reno has purportedly perfected time travel technology. The SEALs use it to travel backwards to the year 112,000,000 BC (despite the movie's title) of the Early Cretaceous, in order to rescue a previous, 1949 expedition led by Reno's brother Erik (Christopher Atkins).
Four astronauts in 1960 travel to a planet called Nova that has just entered Earth's solar system. The crew begins studying the planet to see if it's suitable for a possible Earth colony. After first discovering normal Earth animals such as a kinkajou and an alligator, they soon encounter and battle giant insects, an enormous snake, prehistoric mammals, dinosaurs, and - on an island - the titular character, King Dinosaur, a putative Tyrannosaurus Rex. Eventually, the scientists blow up the island with an atomic bomb, killing all of its inhabitants.
Future War begins aboard a spaceship undergoing a revolt. A man enters and activates an escape pod which travels to Earth and crashes into the Pacific Ocean. The pod contains “The Runaway,” a human slave played by Daniel Bernhardt. He is being pursued by cyborg slavers and dinosaurs that they use as “trackers.” Since he was kidnapped some time from Earth’s past, the Runaway is familiar with the English language and the King James Bible and he regards Earth as a literal heaven.
Prehysteria! tells the story of Rico Sarno, a museum curator, who enters a forbidden temple in South America, and discovers a nest of five eggs. He steals them and brings them back to his museum. Frank Taylor (Brett Cullen), a farmer, sells fossils to Rico and in a mix up, the Taylor's dog takes a cooler, which has the eggs. The kids, Monica (Samantha Mills) and Jerry (Austin O'Brien) discover the dinosaurs when they hatch and try to keep it a secret, until their father finds out. Vicki (Colleen Morris), a woman who works for Rico, sees the dinosaurs, she tells the Taylors not to give them back to Rico because he will expose them. Rico finds out the Taylors have them and hires two robbers to help him get the dinosaurs back.
Professor Neelakantan (J. Livingston) is an maverick Indian scientist and inventor who develops and constructs a time machine, and begins experimenting with it. He realises that his machine requires a recognised "object" to work, and he therefore seeks to locate such an object that can be transported in time through his machine. He jokingly tells his pet dog that he would use it as the "object".
Une femme élégante (jouée par un travesti) arrive dans une ferme et demande Monsieur O. Elle dit travailler pour un zoo, et requiert ses services en tant qu'expert en crocodiles. Elle lui apprend qu'un nouveau zoo va ouvrir avec des dinosaures. Il accepte et elle l'emmène au zoo dans la forêt, où il retrouve son ancien amant qui se trouve être le directeur du zoo, Christ. Il rencontre aussi Pat, qui sera son assistant. Mais les dinosaures se révoltent et s'enfuient. Devant cette situation critique, les trois hommes ont besoin de se relaxer.