Weatherby Chesney's "The Lizard" (as by C J Cutcliffe Hyne) (short story, free): A man wakes up a sleeping prehistoric monster
This is not really a dinosaur story, however; the monster is a giant prehistoric lizard. At a certain level, this is of the class of stories where curious humans consciously wake up a sleeping ancient monster, not realizing it's a monster (e.g., Benson Dolling's "Amber Insect" or John Campbell's "Who Goes There?" (download))
Narrator is a "cave hunter", exploring a newly visible cave, & ends up being chased by the monster lizard sleeping there for millennia...
Fact sheet.First published: The Strand Magazine, June 1898.
Download full text from Horror Masters.
Related: Fiction from 19th century.