Captain Tim's crew was the crew of said Tim. They resided on their ship. They were eventually killed by a stray creature when it managed to get aboard. Wander and Sylvia found the ship, and explored in search of survivors, however it was too late for them. The crew's corpses, suits, helmets and bones were later seen in various hallways and rooms. What was left of them was presumably destroyed when their ship was blown up.
Although they were never seen in person, there skulls and corpses were, and Captain Tim was seen in a vlog recording. Given that the captain wore the same suit as one of the corpses (minus the helmet), and the skulls of the crew seen were all about the same, it appears that the crew was all one species (presumably Captain Tim's).