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Volume 1502

Den Valdron
Part of the Exploring Barsoom Series


The Biology of Barsoom in Carter's Time
Life Begins on Barsoom, Following Earths Pattern
Barsoom's Life Diverges from the Terrestrial Pathway
Multiple Conquests of Land, and a Permian Extinction that Didn't Happen
Bigger Bangs for the Buck, Why Ten Legs Beats Four
Ecological Zones
The Birthplace of Barsoom, the Polar Sea
The Martian Mediterranean, Marinis
The Madagascar of Mars, Elysium
Martian Wasteland - The Tharsis Bulge
The Desert Barrier, Syrtis and the Ring Around Hellas and Argyre
Hellas,  A Lost World in the Southern Hemisphere
The Lost Sea of Korus
What is the history of life on Barsoom.   How did it get to the stage it is at now?   From John Carter's Barsoom, the following data formed my core of working knowledge: 

The Biology of Barsoom in Carter's Time

  • Mars has/had fish. 
  • Mars has/had reptiles, mostly associated with or near water. No evidence of amphibians, so either they never found a viable niche, or they all died off in the big crunch. 
  • There are insects, but now mostly they're confined to relic populations. 
  • There are birds, but again, mostly relic populations, in the swamps or around the canals. 
  • There are a couple of species of mammals, but they're small timid creatures that apparently never amounted to much. 
  • Dominant life on Mars appears to be endoskeletal non-reptilian 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. 
  • These vertebrates are distinguished in their numbers of legs. There are four limbed, six limbed, eight limbed and ten limbed creatures. 
  • We don't know explicitly about all of them, but it appears that the four limbed and six limbed specimens are definitely egg layers. 
  • 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 reptiles as we know them. But they're definitely not mammals either. 
  • As far as plants go, the dominant fauna appears to be a hardy purple moss that grows along much of the sea bottoms, and seems to be the staple. 
  • There are martian trees, but they're on the way out, existing mostly in water catchments, or along canals. They seem to be mostly the leafy broad branched variety, rather than the evergreens. 
  • I don't recall much in the way of flowering plants, although they are occasionally mentioned.  There is no mention of flower propagating species, such as bees.   Almost all plant propagation appears to be by wind. 
  • There are mobile carnivorous plants, a 'tree', some 'bushes' and an actual non-sentient 'plant man' which actually more resembles a kangaroo than a human form. The first two are rare, but generally known, the third type is and confined to a single southern hemisphere valley. 
  • Very little mention is made of crops, but by inference, they have to exist to support the cities. I assume that trees propagate by fruits and nuts, there may be grains, berries and bush crops. No mention that I can recall of root or tuber crops. 
So, taking this as our starting point, let us begin to work backwards.   For the canvas, we'll use the modern topographic map of Mars, showing features which are unchanged for billions of years, and we'll assume, as speculated, that Mars once had a vast northern ocean, as well as two great southern seas.

Life Begins on Barsoom, Following Earths Pattern

It is believed that life on Earth evolved on tidal flats. So too on Mars.    Although Mars did not have a moon to produced tides, there were other factors:    Seasonal water level changes caused by the expansion and contraction of the north polar cap might have raised and lowered the seas, and winds blowing from the Polar sea would have pushed up vast amounts of water, creating extensive tidal zones, mud flats and pools which provided a hospitable environment for life to emerge. 

As on earth, Martian life first colonized the sea, and the earliest plants and animals were sea borne. The sea produced corals, armoured arthropods and eventually notochordates which evolved into fishes. 

Interestingly, Barsoom does not appear to have produced mollusks, or if it did, they are long extinct. Nowhere in Burroughs Barsoom chronicles is there mention of shellfish, clams, mussels, oysters, snails, slugs or cephalopods. The mollusks either never evolved or were entirely extinct by Carter's time. 

We can assume that the early evolution of vertebrates was much the same as on Earth. We probably started off with a spinal structure which became armoured with segmented bone or cartilage. This provided muscle anchors to support more powerful swimming. 

The early vertebrates/notochordates outdid their spineless worm and arthropod rivals. They could easily outswim the worms, moving faster and with more maneuverability, even able to swim against currents. They were also far lighter than the armoured arthropods, who also had powered swimming, and could thus swim far more efficiently. So they quickly dominated the waters, leaving the arthropods crawling along the bottoms or confined to tiny size ranges.

These faster moving creatures needed a more efficient respiration system.  A gill system evolved, swallowing water through the mouth and passing it out gills.  The gill slits had to be supported by arches in order to open and close and support the stresses of constant flow.   The rigid structure of the gill slits calcifies become the precursors to ribs, their arches being doubled and redoubled along the length of the body, adding support and strength while protecting the inner organs. 

The gills and fill arches needed to be somewhat flexible, so they weren't anchored directly to the spine.  Instead, they were loosely hinged, allowing some movement as the animal swam.

This allows the fish to grow to larger and larger sizes.   There's a limit to how big a fast moving creature can grow when its insides are merely a squishy bag without support. 

Meanwhile, the first few ribs, or gill slit arches, which are already hinged,  move forward, becoming jaws.  Teeth are developed from specialized skin scales.   Fins, either lobe fin or ray-fin are simply another development of the hinging trick done with ribs, only with increasing amounts of muscle attached directly to them.

It's not clear if Mars went to cartilaginous fish, although that's quite probable. Armoured fish appeared on Earth and represented a huge blind alley of evolution, this may or may not have happened on Mars. Lighter gravity might have made it easier on the armoured fish as far as swimming and maneuvering went, so they may well have made an appearance.

On Earth, Lobe Finned fishes evolved, apparently contemporary with, or even prior to Ray Finned fishes (the modern kind). This may imply that the 'lobe finned' development was an early and natural outcome of the bone and hinge evolution.

A protolung in the form of an air bladder also seems like a fairly natural development, since among fish, it appears to have evolved independently at least a couple of times. Lobe Fins, Mudskippers and Lungfish all come to mind.

I'm assuming that equivalent air gulping Lobe Finned fish, or something very like them, evolved on Mars. 

Barsoom's Life Diverges from the Terrestrial Pathway

Of course, on Earth, large tidal flats proved to be an environment that Lobe Finned fish could survive and move around on. Their adaptations or evolution allowed them to survive in the air, and make their way from one pool to the next.   Eventually, this gave rise to the four legged amphibians, who in turn went on to dominate the planet, and give rise to other four legged species.

But that's because Earth is a bit different from Mars. On Earth, we had a single world ocean, and a more or less continuous supercontinent, Gondwanaland. So, a successful evolutionary leap in one area might well spread right along the coasts uninterupted.

Martian geography was a bit different. Okay, now yes, there's a single polar ocean. But this ocean is configured a bit differently.

Stay with me here. Life is not going to be crawling out onto land at arctic floes, right? Nope, the transition to landlubbers are going to happen much further south in the temperate latitudes. And its going to stay there for a while. Your basic lobe finned graduating up to amphibian is not going to be going 'Arctic circle here we come!'

Now if we look at the Martian altitude map, we find that as the Martian ocean reaches south, it divides into three isolated lobes, each separated by two large expanses of land and highland, and a subcontinental volcanic island plateau. The lobes are Utopia, Acidalia and Arcadia. 

And each of these big lobes further give rise to isolated sheltered bays, Valles Marinis, Isidis, and Amazonia.

Now, what this means is that on Earth, the Lobe finned fish that made the successful transition to Amphibian could start out anywhere and gradually colonize the whole continent.

On Mars, most likely, the Lobe finned fish that successfully colonized the land as an Amphibian was probably stuck in a comparatively small sheltered sea or bay. Colonizing the entire coastline would mean moving up into colder and more inhospitable waters and lands, which would take a lot more evolving to handle.

So, the lobe finned amphibian stayed where it was, and concentrated on refining its act, for convenience, we'll just say its Arcadia.

Which meant that the other two ocean lobes, Acidalia and Utopia, had miles and miles of virgin seashore, just waiting for some other breed of local lobe finned fish to independently try the same trick.

Now, here's the interesting thing about the Coelecanth on Earth. It doesn't just have four lobe fins, its got six. In fact, we get all kinds of numbers of lobe fins on fossil fish, including odd numbers on fossil lobe fins.    Four wasn't a magic number. 

But on Earth, what probably happened, was that it was a four limbed lobe fin that got the jump onto others, colonized the land, and shut all its brothers and sisters out. And that's why, ladies and gentlemen, all Vertebrates on land are four limbed critters (setting aside a few snakes and flightless birds).

Except on Mars, there are at least three major separated sea/seashore biomes in the polar ocean, and quite possibly a few more minor ones. So, somewhere a four lobed fish makes it. Somewhere else an eight lobed fish becomes an Amphibian. Someplace else a six, and elsewhere even a ten.

Then they're all stuck. They're all in isolated biomes with no ability to get to each other. So here evolution slows down. You have all these relatively small, relatively isolated populations. It's not a recipe for rapid advancement.

Basically, they're all sitting around in their amphibian cottages, watching the sun rise, producing generation after generation, and accumulating the evolutionary advances that will allow each of them to penetrate into dryer country, penetrate into colder country. But apart from that, life is slow and easy. These are the Martian salad days.

Or are they? There's huge seasonal tides along with wind tides, so there's lots of opportunities for ambitious amphibians. Maybe they're not evolving as slowly as we think. But one thing that's for sure, every group is facing the same evolutionary and habitat pressures, and so springing from a common genetic heritage of lobe finned fish, their consequent adaptations are similar and happening at the same rate. 

There isn't even really that one big habitat that would allow one line to really get pumped up. They're all occupying ecological biomes of about the same latitudes and the same surface areas.

Multiple Conquests of Land, and a Permian Extinction that Didn't Happen

Martian amphibians and later Martian land animals came in four, six, eight and ten legged varieties, each variety establishing itself in isolation at the base of each Ocean lobe, and then expanding outwards to encounter and evolve in competition with each other.

Of course, once they start encountering each other, then evolution starts to take off. Fortunately, or unfortunately, its not a biological massacre, like placental mammals in South America. Each population has had the opportunity to develop at about the same rate, so while some lines take hits, most survive. 

Perhaps there are two legs or twelve leg lines that get wiped out. But the 4, 6, 8 and 10 legged lines all manage to stay in the game with each other, sure each of them loses some species to competition and extinction, but each of them produces successful species that invade the others biomes.

The result is an explosion of adaptation as multiple lines continually invade and reinvade biomes, and colonize and create new biomes, continually adapting and evolving.

The amphibians are superseded by the reptiles. Colonization of dryer and dryer lands leads to hardier and hardier forms, who then return to the lowlands, pushing aside reptiles and amphibians. The Martians are out there pushing into empty spaces, trying to build the better beast.

In the evolutionary terms of Earth, Mars has reached its Permian period. 

On Earth, our Permian was an explosion in the seas and lands, a heady period which saw, in succession, Amphibians, and almost immediately after, the emergence of Reptiles, Lizards, Turtles, Crocadilians, Archosaurs, Mammal-Like Reptiles and perhaps even Mammals. On Earth it was a brilliant booming time that produced an amazing diversity of life and some remarkably sophisticated animals, all dominated by the Mammal-Like Reptiles who seemed well on the way to going places and doing things.

So what happened on Earth? Just the biggest Mass Extinction in recorded history. A bigger Mass Extinction than the dinosaurs. Perhaps it was an asteroid, perhaps something else. But suddenly 99% of all plants and animals were extinct. In particular, the Mammal-Like Reptiles, who had managed to dominate the planet and shunt off all competitors into the margins were entirely wiped out.

Instead, after the extinction, the Dinosaurs took over. They were less efficient than the MLR's, their brains were smaller, metabolisms creakier. But nevertheless, they were ahead of the other reptilian and amphibian forms. They shouldered aside the mammals, and took Evolution down the Mesozoic river, a 200 million year blind alley.

On Mars, the Permian mass extinction never happened. Evolutionary pressure pushed each of the lines to develop their own rude forms of mammal-like reptiles, and they all just kept getting smarter and tougher and more efficient competing with each other. There was no 200 million year blind alley.

Bigger Bangs for the Buck, Why Ten Legs Beats Four

Of course, the different lines did find different advantages. One of these was weight distribution. Ten legs carry weight better than four legs. Now, the gravity is light, that's not a big deal... until you are becoming a big deal. Suddenly, if you're getting hefty, having eight or ten legs to distribute the weight load along becomes an advantage.

Martian ecology begins to shake out along size lines. Up around Dinosaur size, the ten legs rule. Around Elephant size, the eight legs find that they can go head to head with the ten legs, their advantage isn't big enough that they can't overcome it.

Around the size of a cow, bear, buffalo, rhino or large critter like that, the six leggers become competitive. The weight distribution advantages of 8 to 10 legs become minimal. It's turning into a three cornered fight.

Go down another size level, to a few hundred pounds, man or deer or mountain lion and down, then the four legs enter the fray. It's now a four way contest, and here is where the evolutionary pressure starts to get truly fierce.

Because that size range, is also the upper limits of where mammals, insects and reptiles can still consider themselves somewhat competitive on Mars.

So, on the small scale, you've got at least seven major evolutionary lines, all fighting it out. That's going to call for some impressive competition, a lot of speciation and specialization, a real biological laboratory of adaptations.

So Evolution progresses swiftly. The Martian ‘Mammal-like’ reptiles are operating very much on mammal levels as far as energy, muscle and intelligence are concerned. Hell, they're all using everything they can grow their hands on.

Winners and losers shake out. The big losers seem to be mammals and reptiles, who are pushed to the margins of the ecology. In John Carter's time, they're both still around, but fairly no-account.

The four legged critters take a pounding. There's other advantages than weight distribution in having extra limbs. You dig faster and deeper, you run faster and further, swim better, what have you. In fact, by John Carter's time, just about every four legged species is extinct, the entire lineage is mostly gone...

Except for one clever little line of fourlegs, who have out of sheer desperation, their evolutionary back to the wall, have learned to make and use tools.

How about that.

Ecological Zones

On Earth in its early history, there were only two significant ecological zones. The single land mass, Gondwanaland, and the world ocean that surrounded it.

Gradually, plate tectonics split Gondwanaland up, creating continents, mountain ranges, islands and isolated seas. South America, Antarctica and Australia split off some sixty million years ago, each developing its own unique flora and fauna. Later, Madagascar and New Zealand became separate island ecologies. Eurasia, Africa and North America were loosely linked. The Atlantic became a separate water body, as did the Mediterranean and to an extent, the Caribbean. North America split from Eurasia and joined South America. Africa, Asia and Europe were partially isolated from each other by seas, mountain ranges and deserts. 

In short, Earth in its evolutionary history began as a relatively uniform area and then slowly divided up into a multitude of ecological zones, which separated and then reemerged over time.   And in fact, the break of earth into different ecological zones, and the separation and unification of those zones helped to chart the course of life and evolution on Earth.

The history of ecological zones of Martian life is much different. Without plate tectonics, the geography was much more stable and uniform, but it was effectively diverse in structure from the start.

Ecological zones emerged on Mars with permanent, although not insurmountable barriers of seas and geography.   This made it both easier and harder on life.  The barriers of geography were, as I said, not insurmountable.   Life forms could travel through the whole of the planet.  On the other hand, it wasn't going to be easy, and so life forms had to be adapted to a certain degree of hardiness to overcome the geographical obstacles.   There were no free rides brought about by continental plates joining up.
The principle ecological zone was the Polar Ocean that dominated the Northern Hemisphere. The Ocean extended into three lobes which provided some diversity in local fish and plant populations.

The three lobes of the Polar Ocean also meant that there would be three, loosely connected and interrelated lowland equatorial areas each with slightly different conditions, which may have contributed to the proliferation of vertebrate life forms. 

Each equatorial lowland seemed to develop in its own way, but overland and coastal transmission meant that as they each expanded, they encountered and began to influence each other. As many species are common to all three or two out of three as are particular to only one. Of the three, the most unique, geologically, and biologically is Marinis Valles.

Around the sea, ecological zones emerged based on altitude above sea level, thus seasonal tidelands emerged near the seas, rain forests above the maximum sea levels, grasslands above the rain forests and finally deserts in the highlands.

Elysium and Hecates, geographically separated from the mainland evolved radically on its own. In the southern hemisphere, vast deserts of Tharsis and Syrtis acted as geographical barriers, slowing the spread of life and isolating it. Life did not originate independently in the Oceans of the Southern hemisphere, but travelled there as primitive or hardy forms from the north, who swiftly adapted to the relative prosperity of the Hellas and Argyre regions.

The Birthplace of Barsoom, the Polar Sea

For ancient Barsoom, the polar ocean was the planet's engine. Due to greater distance from the sun, the martian environment was proportionally colder and less energetic than the terrestrial. This is moderated somewhat by the shallow northern polar ocean which maintains a high level of biological activity, equivalent to sub-arctic and sub temperate ocean areas. The cooler temperatures meant that the waters were saturated with oxygen and the lower gravity dramatically increased the nutrient content of the oceans and seas in terms of suspended sediments or dissolved constituents.

The great polar sea and its tributaries were biologically intensely active, teeming with multitudes of fish. In the shallows, lobe finned fish predominated. On sea floors a variety of arthropods devoured the slowly drifting vestiges of the biological feast above them. Barsoom produced a variety of fish, including analogues of sharks, rays, eels and whales.

The Polar Ocean was a single continuous body, so there would be a degree of commonality to its species, particularly for fish or arthropod species that were adapted for northern waters, or could survive passage through northern waters. 

But moving south, the Ocean divided into three lobes. For southern adapted fish and arthropods, the northern reaches formed a subtle barrier, allowing species to diversify and specialize. Each southern lobe offered its own mix of hospitable shorelines, bays, coves, harbours, valleys and lowlands, and so we can imagine a lively and diverse series of coastal fisheries.

Likely or most of the early permanent communities of Barsoomian hominids were based on fisheries rather than agriculture. The sea, once again, was the mother, this time to Barsoomian civilization.

The Martian Mediterranean, Marinis

The Marinis Valles canyon system, a huge gouge that stretches across 3600 miles of modern Mars with trenches up to ten miles deep is flooded and is an adjunct to the Acidalia lobe of the Polar sea. 

Hydrologically, it does not behave like the rest of the ocean. The deep canyon trenches and high ridge walls provide a degree of climactic and environmental stability that is unique. Marinis has the most stable and consistently warm climate on the planet, even the seasonal fluctuations in water level are reduced here.

The Madagascar of Mars, Elysium

The shield volcano that created the Elysium Montes platform was never part of the Martian mainlands, and never connected by any kind of land bridge. Accordingly, like Madagascar or New Zealand, life evolved in its own directions.

The Elysium Montes area constituted a central land mass, with an equally large hinterland of seasonal tidal lands, and a large network of islands, many of which were isolated from surrounding lands, or submerged completely, during the summer high waters.

Geographically separated for all of its history, life took some different turns here. Lobe fins and amphibians colonized the tidal lands, as had been done on the mainland. Even the primitive seagoing reptiles made it over, as did many species of wind borne or water borne plants.

After that, things went off in their own direction. The relatively small land mass, large tidal flats and multitude of islands gave a permanent advantage to semi-aquatic forms. Land based life had trouble getting started. 

Arthropods were likely the first to successfully colonize Elysium, and a variety of gigantic insects and spiders flourished on the permanently dry land, many using the power of flight to reach the lands and propagate themselves, reaching the absolute limits of size under the square cube rule. 

Lizards and reptiles tended to dominate along the shores and swamps. Developing into titanic serpents and huge dinosaur like foragers.

Birds were a relatively late addition to the environment of Elysium Montes, and fought a protracted war with flying insects for a foothold.   Elysium probably had a variety of winged and flightless birds, including some of the largest species on the planet.

The regular varieties of land animals, whether four legged, six, eight or ten, would find it difficult to reach Elysium, forever out of reach across the sea.   Only the aquatic or semi-aquatic types would be able to reach it, and they might find little incentive to colonize the land.    The local lobe fins might evolve into ‘legged’ animals, but there would be a very good chance that these creatures were poorly adapted and more primitive than their mainland cousins. 

The only mainland animal that could truly colonize Elysium was a sailing species:   Man

Mars poster by Ballantine ~ Art by Gino D'Achille
Click for larger image

Martian Wasteland - The Tharsis Bulge

The extreme highlands of the Tharsis Bulge, the home of most of the Martian Volcanoes and a huge volcanic shield plateau amounted to some of the coldest, most inhospitable zones on the planet. 

Arid and nearly devoid of moisture, by reason of its extreme altitude the bulge frequently sported thin air, blistering hot and cold temperatures and savage storms.

Life on the Tharsis Bulge was likely to be hard, brutish and short. Many conventional Martian plant and animal species probably colonized the bulge, but tended to evolve rapidly to suit the harsh conditions. Martian trees and plants grew stunted, with withered leaves designed to conserve moisture and thick root systems. 

The animals which survived up there tended to become Dwarf versions of the originals. Thus, there was a probably omnivorous Dwarf Thoat, Dwarf White Ape, etc. Life evolving for Tharsis did poorly in the more generous lower latitudes.

All around the Tharsis bulge, in the shadow of great volcanoes, we would expect volcanic vents, steam vents, geysers and small deep canyons. Essentially a series of microclimates of extreme conditions, perhaps some of the hottest and moistest habitats on Mars. It would be fascinating to see what colonizes these inhospitable regions, and how they adapt to their new homes.

The Desert Barrier, Syrtis and the Ring Around Hellas and Argyre

Syrtis is an arid desert area, roughly boomerang shaped, which separates Hellas from the Polar Ocean and lowlands in the north, to Korus in the west. The Syrtis desert comprises a wide variety of biomes from harsh sterile desert at its core, to tundra, moderate or mild desert and scrub lands towards its periphery.

Syrtis was probably the area closest to modern Barsoom, and likely it was the birthplace of many of the surviving species of John Carter's time.

Syrtis is not so much an ecological zone as a barrier to ecological zones. The life at its edges is often most influenced by its immediate neighbors. Only a handful of plant and animal species, such as the White Ape are both native and range widely.

Hellas,  A Lost World in the Southern Hemisphere

The northern hemisphere and the polar ocean and its shores were the origins of life on Mars. But in the southern hemisphere, two large seas, Hellas and Argyre were isolated bodies of water, separated by several thousand miles from each other and from the northern water complexes.

On Earth, the oceans interconnect, and isolate islands and continents. Australia, New Zealand, Madagascar were all isolated areas which allowed life to evolve differently. On Mars, the Tharsis bulge and Martian desert highlands formed massive barriers which isolated and created ecological ‘island continents around Hellas and Argyre.

Sea life and river life was effectively cut off from the southern hemisphere water bodies. But wind was a major vector for transmission of seeds and spores from land and shore plants. Soon, the empty seas were surrounded by plant ecologies which had blown south, and began to evolve radically on their own. Wind based colonization was impeded by the fact that the southern hemisphere was cooler than the northern one, and thus winds tended to blow strongly north to south. 

This meant that while wind seeded plants might find a southern-going wind, these tended to be the lightest and often the most basic and widespread plants. Many plant species with heavier seeds or travelling at lower altitudes never got out of the northbound winds and failed to make it south. 

The southern hemisphere started with substantially less biodiversity than the north. This meant that the few life forms that did make it down found empty ecological niches literally on every side, and swiftly began to proliferate to take advantage of these new opportunities.

Animal life, travelling overland, eventually made it to the empty seas of Hellas, where over millions of years, many forms returned to the sea, taking advantage of lack of competition from water breathers. The Hellas sea was populated by equivalents of Martian dolphins, seals, otters, sea cows, crocodiles, turtles and perhaps even mermaids. On the shores of Hellas, other specialized variations of primitive Martian animals evolved, creating an ecological biome as unique as Australia.

Hellas became the dominant biome of the southern hemisphere. Plants and amphibian and desert animals evolving around Hellas spread to the multitudes of empty crater lakes in the southern hemisphere. A variety of animals spread out from Hellas, adapted for cold weather, erratic moisture and harsh conditions.

The Lost Sea of Korus

Argyre is Mars smallest ocean or sea. Argyre, was directly south of the Valles Marinis biological zone, in primeval times, it was loosely connected by a winding series of lowlands and oasis known as the Iss Corridor. The Iss Corridor allowed early Martian plants, but not animals to colonize the Korus sea complex. 

The Iss Corridor was a precarious series of valleys and oasis which formed a barrier to fish and to most of the primeval Martian land and insect life. Instead, prehistoric martian plants were able to propagate themselves in stepping stones through the corridor, during freakish wet periods that may have lasted only a few years or even months over millennia or millions of years, before finally establishing themselves in Argyre.

The plant life of Argyre has many resemblances to some of the earliest prehistoric plant life of the polar ocean lands, back before animals had truly learned to dominate the surface. Without animals for competition, plant life in Argyre evolved and diversified in strange ways. Separated from winds by the high ridge walls, many found alternate means of propagation. Some eventually evolving mobile and semi-mobile forms, becoming animal like, in replacement of missing animals.

Meanwhile the shallow valleys of the Iss Corridor were desicated by their proximity to the Syrtis and Tharsis highlands. The oasis dried up for millions of years. A partial warm humid spell, millions upon millions of years later allowed a second invasion of small northern hemisphere plants and animals, mostly reptiles. But by this time, the native plants had evolved so far and were so well established, and the invading plants and animals were so small and weak in comparison, that they were simply incorporated into the ecology and local mobile plants became carnivorous to prey upon these new sources of food.

The ultimate result of Argyre unique evolution were the feared Plant men of the Dor Valley, and a variety of man eating plants, including a semi-mobile tree that, although fixed, could seize prey. Some of the exotic and motile plant forms were transplanted by homo ares into small pockets in the northern hemisphere, where they survived to John Carter's time.

Animal life remained marginal. Reptiles returned to the water and gave rise to a unique range of eel like creatures known as silurians.

Argyre has had some ecological influence on its surrounding biomes, although not as much as Hellas. The crater lakes closest to the pole and adjacent to Argyre contain primitive but hardy plant life closely related to Argyre forms. However, due to harsh conditions, much of it is fairly primitive. There are many crater lakes where Argyre and Hellas plant life are found, but Hellas invariably dominates. 

The motile plants are not seen in any of the crater lakes and are unique to Argyre Korus regions.

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