Complex sentence: George Gaylord Simpson, a vertebrate paleontologist at the museum, subsequently visited Craighead Caverns in May, 1940 where he recovered additional jaguar bones and made casts of several jaguar footprints in the mud floor of the cave.
Split into simpler sentences: George Gaylord Simpson, a vertebrate paleontologist at the museum, subsequently visited Craighead Caverns in May 1940. During his visit, he recovered additional jaguar bones and made casts of several jaguar footprints in the mud floor of the cave.