Epona: The COTI Mundi World
Created by Martyn Fogg and the COTI Mundi Team*


Artwork by Steven Hanly
COTI Mundi was born after CONTACT's annual gathering in 1992. Suggested by COTI co-ordinator Dirk van der Elst, the new project was motivated by the desire of many of us to expand COTI -- our intensive but exhausting 3-day world-building, alien-designing, culture-constructing contact simulation -- into a longer term project that could broaden participation, give increased attention to detail, and allow for more thoughtful and rigorous scientific speculation. An international team, headed by Martyn Fogg and Greg Barr, embarked upon a three-year project and has produced for us this wondrously rich and exotic world, Epona. Supported by hundreds of pages of documentation garnered from countless hours spend at the conference, on the internet, and in the study, Epona is quite likely the most thoroughly researched imaginary world ever created. It has its own web page here: worldbuilders.info

Larry Niven, veteran of many CONTACTs and keynote speaker at CONTACT XII, enthused on Epona's final presentation at the conference in 1995:

"Half the secret of Epona is [COTI's] 20 years of practice. The other half was in realizing that a week wasn't long enough. Epona was three years in the making ... I've never seen a playground this size!"

* The Team: Paul Birch, John Bray, Julie Carlin, Randall Clague, Del Cotter,.Keith Halperin, Steven Hanly, Howard Hendrix, Anthony Hobbs, Jon Hoffman, Aleta Jackson, Stefan E. Jones, Jeff Kallman, Karl Kofoed, Geoffrey A. Landis, Edward E. McClanahan, Steve Mitome, Dave R Moore, Donn & Chris Mukensnable, Gerald D. Nordley, Paul Preuss, Wolf A. Read, Susan Sackinger, Donald Scott, Edward Kenneth Smallwood, Trevor A. Sproston, Roger & Nancy Zuidema, J Gert van Dijk, and Gerard van Leusden.

Bateson Project: COTI Mundi - Epona
Summary by Wolf Read, edited by Jim Funaro © 1995 Contact

Epona's Family of Worlds

Epona is the third world of nine which circle the star 82 Eridani, now named Taranis. Taranis is a single G5 V main-sequence star that is roughly 5 billion years old. The star resides in the constellation Eridanis, and currently drifts in its galactic orbit some 21 light-years from Sol. The four inner worlds of Taranis, including Epona, are terrestrial in nature, being small, ranging from 0.09 to 2 Earth masses in size, and having average densities within the range of rock, from 3.8-6.4 g/cm3. The inner two worlds, Belenos and Grannos respectively, are similar to Mercury, with small bodies, high densities and little in the way of atmospheres. Epona follows, with a mass of 0.55 Earths, an oxygenated atmosphere that averages 0.577 bar at the surface, continents of silicate rock, temperate climate and seas of water. Sucellus, the fourth world, has surface conditions similar to what has been hypothesized for Mars early in its history The next four planets are a family of gaseous giants, hot, dense Rosmerta, huge Borvo, Bormo with its extreme axial tilt, and Bormanus circled by an icy ring. The final world, Sirona, is Tritonian, being comprised of ices, though it is more massive than Mars. This system shares many characteristics with our our own. The orbital spacing of worlds is similar to that of the Solar System, with separations increasing in a roughly logarithmic progression from the sun. The orbital positions represent stable points among the gravitational resonances between Taranis' worlds, so the similarity in spacing between Epona's system and Earth's is not unusual. Included is a diagram showing orbital position and mass of the nine worlds comprising Epona's family.

Epona's Geology

Epona accreted a similar distance from Taranis as the Earth did the Sun, so the composition between the two worlds is quite alike. Epona has a slightly lower abundance of heavy elements, which accounts for its slightly lower density. During the first 3.3 billion years of her existence, Epona possessed a liquid iron-nickel core, a convective asthenosphere and shifting lithospheric plates at her surface. This wonderful tectonic activity did not last as long for Epona as it has the Earth, for one big reason. Being a smaller world, Epona has a higher surface to volume ratio than the Earth, and thus has had its store of internal heat dissipated at a significantly faster rate. By 1.7 billion years ago, Epona's tectonism began to slow significantly, and later it froze up completely as the lithosphere continued to thicken. Many types of mountain building stopped, and continental masses simply began weathering and eroding away. Highly weathered continents are okay, as far as Epona's biome is concerned, but breakdown of tectonism has one major side effect for life. Epona's dead geology severs the all-important carbonate-silicate cycle. In a few tens of millions of years, much of the avalable CO2 becomes chemically bound to Epona's crust, leaving a very cold world indeed.

At the beginning of this new era for Epona, some 1.7 billion years ago, her previously equitable climate eroded in the cold clasp of a prolonged ice age. For the terrestrial biosphere, and a little less so the aquan realm, this sustained ice age proved a significant challenge, causing vast extinctions. The very limited CO2 during these times is not enough to sustain photosynthesis very well for terrestrial plants, and most die. Herbivores quickly follow the vegetation's death march, and the carnivores subsequently suffer. In the oceans, photosynthetic organisms are able to survive by using bicarbonate as their carbon source, which keeps an undersea ecology going, albeit a cold one. But, alas, Epona's internal heat had not been completely dissipated. There has been enough to produce residual bouts of terminal volcanism every one hundred million years or so, give or take an epoch or two. These huge plagues of eruptive activity released vast quantities of CO2 back into Epona's atmosphere, providing a new greenhouse effect and an abundant carbon source for photosynthesizing life. Under the warming, the ice retreats, and land areas heretofore covered in glacial ice become exposed for repatriation by life. The volcanism is short-lived, say a few million years or so, and therefore the warm periods only last ten to twenty million years. Long enough for terrestrial life to become established, only to be chocked from the continents as the CO2 steadily drops, allowing Epona to ice over yet again. Epona has experienced at least twenty of these events in the last 1.7 billion years. She's at a warm-period's end right now, in our modern era. Much new aerial, terrestrial and sea life has evolved in the ten million years of equitable clime that has currently persisted on Epona.

Eponan Geography

During present time, Epona's major landmasses can be broken down into two major components. On the eastern limb is the Sunken Continent region, known also as Tir fo Thuinn. On the western limb, mainly in the northern hemisphere, are the Highlands continents, known also as Ard-Thir. Tir fo Thuinn is an ancient tectonically dead continental craton that has been weathered by rainfall and glacial action for at least the past 1.0 billion years. As a result, the land is flat, and shallow, not too dissimilar to Earth's Florida, but on a much larger scale. Due to the scouring action of continental glaciers, many fjords have been created, and what was once a single vast continent is now a menagerie of islands and subcontinents. Ard-Thir marks a huge blemish of past and modern terminal volcanism on Epona. This is where many eruption episodes have occurred, forming a bulge similar to the vast Tharsis region on Mars. Old volcanoes, achieving some 10 km in height, dominate the landscape along with steep ridges and valleys filled with volcanic rock ranging from basalt to various ash-flow tuffs - though apparently the former is much more common than the latter. An interesting point of volcanism is at a spot called Fire Island, or Teine Eilean. This is where relatively numerous explosive eruptions are still occurring (roughly once a century) from a single 11.5km high peak, the highest point on Epona. Teine Eilean has been arbitrarily placed at 0 degrees longitude, and nearly resides on the equator, making for the simple coordinates 0!, 0!.

Epona's Biology

Epona supports a vast and complex biology, and enough body plans have been developed for a full and integrated Eponan biota. The Tir fo Thuinn region of Epona has been particularly well studied. We'll sample a list of its denizens, and then concentrate on the group that has produced a sentient form.

The Archaeanimalia Kingdom: This kingdom consists of animals that have a somewhat Earth-like morphology and physiology. But though the archaeanimalia have some similarities to Earth critters, such as mineralized skeletons (both internal and external) and similar musculature, there are no vertebrates, and members of the existing archaeanimalia classes are quite different from anything existing on the Earth.

The Calcariopodans fill a niche similar to that filled by insects on Earth. They are a class of relatively small segmented organisms that are supported and protected by an exoskeleton of calcium carbonate. They carry an assortment of appendages with them, a legacy of their ancient ancestors. Modification of the numerous limbs is common, with typical products being the creation of liquid-filled spines for sensing sound waves and grasping organs quite like those used by some arachnids and crustaceans on the Earth. The unique Segmented Dragonfly is a communal organism, in a sense. The critter has five segments sharing a common nervous system but each one having its own digestive and circulatory system, so that when food is acquired, it is passed from one to the other segment (usually from the back forward) for a bite or two. The SPRINGCROCS are, well, weird. Looking somewhat like a single-legged clam in their basic form, one would hardly guess that they rate amongst the most vicious of predators on Epona. All acquire prey by the somewhat passive method of hiding under cover and then pouncing upon a hapless prey item that has wandered too close.

The Archaeplantae Kingdom: This kingdom contains photosynthetic organisms that superficially resemble Earth's plants. One prominent member is bubbleweed, which has small balloon-like leaves which are used for storing CO2. The plant is pelagic, and lives on the sea surface, sending rootlets downward while spreading laterally. There are many other archaeplant species, though many have not been identified at this current time.

The Myoskeletal Kingdom: This kingdom consists of organisms that possess no mineralized skeleton whatsoever. Instead, they have a structure supported by corded muscle, called extensile muscles, which gives the metazoans a very flexible and extendible body. The basic body plan in the myoskeleta consists of a barrel like midsection with five limbs protruding from either end. The tips of the five limbs are then further divided into three smaller digits. The kingdom is broken down into two phyla, the myophyta, which consists of photosynthetic organisms that are assuming plant-like niches on Epona, and the pentapoda, which has produced a host of animals.

Myophytes: These photosynthetic organisms, which have evolved from a tiered seaweed, have a very simple form: The above mentioned barrel is often carried upright, like the trunk of a tree, and the five limbs on one end are sunk into the ground, like roots. At the top of the barrel, the other five limbs have evolved into a large umbrella leaf, so that a single tiered member of this phylum looks somewhat like an oversized mushroom

Pentapods: In pentapods, the basic myoskeletal barrel contains all the vital organs, including the brain, and the sensory apparatus, which consists of four eyes, two ears and, a third ear located on top of the head that serves as a sonar sender/receiver. The Pentapod Phylum has produced at least two well-known major groups on Epona, the avians and the ceretridons. Both groups have diversified significantly in the past ten million years, and contain many species.

The Ceretridons: The pentapod's simple form has been modified significantly in the ceretridons. The barrel has elongated and grown larger, housing a massive digestive system (especially for the herbivores), and has become fenestrated to reduce weight. Thus the barrel looks ribbed. A head-like structure exists at the front end of the barrel, though it only is a housing for the sensory organs - the brain is still deep within the original barrel. The sonar ear is practically nonexistent, for it has atrophied in favor of eyesight. All ceretridons utilize their four eyes, with many having a pair aimed forward for binocular vision and a pair aimed upward to spot aerial predators. At the front of the head is a simple mouth that has four to twelve conical, chitinous teeth and a single tongue. The teeth represent the terminations of the fingers on what would otherwise be four of the standard pentapod five arms that originate from the front of the barrel. The tongue is the fifth limb. Five other limbs originate from the back end of the barrel. Two arms are carried forward, often inside the body, so that they protrude from the sides of the ceretridon head. They are used for grasping. The other three limbs trail behind and become the legs of the animal, hence the name. However, there are thousands of species of ceretridontid, and many locomotor patterns have evolved among them: monopedal, bipedal, tripedal, and even quadrupedal and pentapedal (using the "arms" by the head). The class has also produced carnivores, herbivores, scavengers and parasites along with those different leg numbers.

Epona's Sophants

The Avians: Similar to the ceretridons in construction, save for a few important aspects. Two of the three standard ceretridon legs have elongated in towings that sit near the head of the critter, while the remaining leg has grown very large, lengthening its three fingers to support another (two-part) broad wing, one that is larger than the two previously mentioned lifting members. The middle finger stretches through the fluke of this large hind wing and becomes a tail that effectively pulls the beast's center of mass into the same region as the center of lift achieved by this massive wing. Also, a triangular sonar "ear" sits ahead of the eyes on top of the head. Sonar is the avian's primary sense, though their eyesight also tends to be good. Eyes in avians are often located on the side of the head, giving the creature a 360 degree field of view. Usually one pair of optical sensors are highly atrophied. The avians have produced Epona's sophont, the Uther, or Eponas utherensis.


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