One of the critical things we have to understand about the Martian ecology is that it has clearly undergone a catastrophic mass extinction. This is not a wild guess if one bothers to take a look at the remaining species: The ten-legged dinosaur-sized Zitidars, the eight-legged thoats, the banths, calots, white apes, soraks, etc... These are all highly evolved and fairly distinctive creatures that inevitably came from an extensive evolutionary line, but are now reduced to a few individuals. Notably:

• Mars has fish, but these are mostly confined to the underground seas (Omean and Ayathor) at the poles, as well as the Sea of Korus.

• Mars has reptilian fauna, mostly associated with or near water, but no evidence of any extant amphibians, so either they never found a viable niche, or they all died off in the big crunch.

• There are arthropoids, but now mostly they're confined to relic populations.

• There are avians, but again, mostly relic populations.

• There are a couple of species of mammalians, but they're small timid creatures that apparently never amounted to much.

• The dominant life on Mars appears to be endoskeletal non-reptilian egg-laying vertebrates. These vertebrates come in all sizes, from that of a dog or a cat, all the way up to elephant and dino sized critters, and are distinguished in their numbers of legs. There are four limbed, six limbed, eight limbed and ten limbed creatures. All of these vertebrates seem to have high constant levels of activity, and show signs of being endothermic (warm blooded), so they're definitely not reptilians as we know them, but they're definitely not mammalians either.

Of the Avians, a few exist, though they cling to the fringes of the post-extinction biosphere.

Malagor

A giant, "prehistoric" Martian bird with a 40-ft wingspread, Malagors (also known as malagawrs or simply gawrs) are used as beasts of burden in the country surrounding the Tanoolian Marshes, as well as the country surrounding the Thakkor Marshes. Opportunistic omnivores, Malagors feast on a diet of plants and small to medium sized animals, and often congregate in large flocks.

Therne

Related to the Malagor, the Therne is a small flock-dwelling predator/scavenger of Mars' polar areas. These avians have abandoned flight, and repurposed their wings into organs similar to the forelimbs of a preying mantis.

Rodal

What can be said about this riding beast? Simple.

A Rodal is disgusting, and riding one is even more so, and is only domesticated because of its ability to survive in habitats where more common draft animals such as the Thoat, Slidar, and Vortlup cannot.

It is a large, flightless avian, with a gait designed to reduce a rider's spine to rubble, and with a considerably more unpleasant disposition. Its temper is short, its disposition unpleasant, and its contempt for a rider is boundless. There is apparently a lively debate over whether it is better to ride a Rodal or merely to be kicked to death by one. It is said, however, that a Rodal has a sort of loyalty in that it will never ever leave a rider behind... because it hasn't finished making them suffer.

In the wild, Rodals congregate in flocks of 10-15 individuals, led by the most aggressive female. They are opportunists, eating everything edible indiscriminately.

Koree

The Koree (or koroo) is a massive, solitary predator related to the Rodal. Its wings are covered with sharp, horny protuberances which make them quite formidable weapons, and indeed these are one of the few beasts capable of taking on an adult Zitidar.

Caldecta

A Martian avian with a feathered wing membrane, the Caldecta is a wide-ranging scavenger, and one of the most successful of all Martian avians, being found across all habitats on the planet

Ombrion

Commonly found in Mars' more desolate areas (near the poles, the deserts, etc...), the Ombrion is the most recent of Mars' animals to be domesticated, a flying mount capable of carrying its rider longer and through rougher weather than the Malagor.

This species exhibits sexual dimorphism. Males are twelve feet in stature, with iron grey plumage which turns to dark green on the edges of the wings and tail, a tuft of jet black feathers on the head. The average wingspan of a male measures 50 feet.

Females are more colorful, their plumage a rich lavender color mottled with dark brown shades, the breast from the throat down is snow white, while the wings and tail are edged with bands of golden yellow. A red crest tops the head of the female avian. Females are also smaller, with a 9-foot stature and a wingspan of 36 feet.