Although existance of life on Mars has been hypothisized in the literature of Earth since at least 1880, and belief in current life was dispelled by the numerous Mars missions during the late 20th century, and then conclusively proven wrong by the manned missions to Mars during the mid-21st century, and the follow up missions in the late 22nd century, the recent appearances of Timewarps have proven that at one point in the distance past, Mars was definately inhabited by an unknown species. No living example of this race has been found, although numerous examples of their technology have been experimented with in the Martian Cities available through the Timewarps.
Although no skeletons have been found, based on the rare samples of artwork and architecture that have been recovered from various Timewarps, it is believed that the Martians were tall, in excess of 3 meters on average, and rather massive in build. They were bilaterally symmetrical, and most likely could perceive a significantly wider range of light than humans can, especially on the high frequency end of the electromagnetic spectrum. There are some contested theories that they were able to naturally see into the X-ray range. Their hearing appears to have been significantly less acute than that of humans, presumably due to the thinner atmosphere of Mars and it's correspondingly weaker ability to transfer sound.
There are only three reliable examples of Martian technology that has been found to date. The most prolific are the conversion machines, found in the Martian cities. These machines are the primary motivation for most prospectors to visit the Timewarps when they appear.
The second is a mysterious artifact that has been discovered by numerous prospectors, that somehow supercharges the Weapons and Defenses of the AREVs far beyond the range that can be reached and maintained with modern technology.