Mesozoic zigzag

The story "Mesozoic Zigzag" has something in common with several epochal works of the last two centuries: "The Lost World" by Arthur Conan Doyle, "Jurassic Park" by Michael Creighton and "The Butterfly Effect" by Ray Bradbury. The heroes find themselves on the Earth of the distant past and encounter the amazing and mysterious flora and fauna of the Permian Period. Escaping and surviving, without expecting it, they set off a chain of events that triggered the Mesozoic zigzag!