Robert Fletcher's original background notes added:
"These were a lizard-like people who were very intelligent and made excellent officers. They had the unusual ability to breathe several different gases, which made them useful members of landing parties. They were also very strong and had four hearts."
Sauria (Psi Serpentis) was the name of a trinary star system in the Alpha Quadrant. The primary was a Class G star. Magnitude of this star was +1, which was 100 times brighter than Sol. Both of the stellar companions were Class G stars, too. Sauria was the name of a planet in the system and was a member of the Federation.
Saurians come in shades of green, purple and brown. Their race predated humanity and they never explored deep into space. Thir brandy is renowned throughout the universe. They are resistant to bright light, can see in the infra-red, has inner eyelids and can breathe different gases. Saurians are good swimmers and made First Contact with humans in 2162.
Starfleet captain An'il'taya was a Saurian. She had the philosophy that you picked the young, ambitious crew for your ship as each has a hunger to develop their career. Once an individual showed that they had peaked or stagnated, An'il'taya sought to replace them once the tour was over. She did not see this as anything personal, just that the person in question would better serve their career on another assignment.