When the Dunwalli vanished from the Galaxy, they left behind possibly tens of thousands of ring worlds, orbital habitats constructed from already existent planets, great ring structures with a biosphere clinging to their inward surfaces.  Over time, these ring worlds slowly broke down, their systems and ecologies no longer maintained.  Entire biospheres vanished, leaving behind barren surfaces covered with the frozen mass that had been life.  Other ring worlds fell into their suns as those stars aged and expanded off of the main sequence.  Only only a few, life remained, their environment stable, existing in a static form as there were rarely any causes for adaptive radiation.

On one such ring world, however, life did evolve, and it developed sapiency.  More than that, this species inherited a technological knowledge left behind by the Dunwalli, knowledge that aided them in their growth to a high technological civilization.  These were the T'zeche, and 747 million years ago they first learned to farm the land of their ring world, and to domesticate the animals that shred the world with them.  For some time the ruins of the Dunwalli were worshipped as holy places, but time and inevitability conspired to bring their curiosity to a point where they no longer took these ruins for granted, and instead they investigated them with a critical and curious eye.  In only a few thousand years, they began to understand the use of Dunwalli technology.

And it was a timely understanding as well, for their world had begun to reach a point where the biosphere was breaking down.  The seas, long silting up, lacking any sort of transfer or recycling of erosional material, began to become anaerobic.  With the dying of life in the seas, terrestrial biomes began to breakdown.  The T'zeche were faced with the end of their world, but by this time they had already learned to travel to nearby stars, and they understood, especially in their case, the importance of extrasolar colonization.

Because of the state of their world, and its slow demise, they also learned a new skill, one that the Dunwalli had utilized but not to a great degree:  terraforming.  For the four million years that the T'zeche moved across the Galaxy, they terraformed with a degree of competency that was almost godlike.  Nearly any world they encountered, they could terraform.  On many such worlds, constant and active upkeep was necessary.  One could not terraform a small asteroid and expect the result to remain for even thousands of years without constant maintenance.  Even moderately sized worlds, such as those around Luna or Mars-size, needed constant attention.  But on larger worlds, the T'zeche had learned to perform the task so that a self-sustaining geological and biological system could maintain itself indefinitely, often to the point of the lifetime of the host star.

Though they existed for a very short time, compared to the Dunwalli and the Angelics, the T'zeche nonetheless managed to spread across much of the Galaxy in a short period of time, terraforming worlds as they went, sometimes multiple worlds in a single system.  It is likely that those worlds which eventually reverted to their pre-terraformed state would still be recognizable as having been altered in the past, but many of the biological markers that would signify them of T'zeche origin will have been lost.  It is these markers, left behind in the very bodies of animals and plants transferred to terraformed worlds, which would identify a T'zeche planet.  The T'zeche are almost certainly gone from this Galaxy.  Why they vanished is unknown, but records indicate that it was a period of some several thousand years that saw their decline.  Yet, while they are gone, evidence of their presence remains in those surviving worlds that hold, to one degree or another, their genetic imprint.

Updates

December 2, 2006

• Added a T'zeche sketch, by Neal Aaron.

February 23, 2006:  Completed the initial write up.

February 22, 2006:  Established this page and its data.

Classification:  Tzechis peregrinus sapiens
Biochemistry:  Carbon-based terrestrial form
Morphology:  Bipedal, with two appendages on their backs that resemble wings, but which may have been used with thermal regulation.  Three tails extend outward from the end of the being, one being used for balance, the other two reaching forward around the body, ending in three phalanges, and being used as manipulators.
Environment:  Gaian worlds were preferred.  A wide variety of habitats were tolerated, though arctic conditions were generally shunned.
Reproduction:  Asexual reproduction, with the infant "bud" being sheltered between the "wings".
Intelligence:  The discovery and use of Dunwalli technology so soon in their development may have contributed to their relatively swift demise, as they were a galactic presence for "only" four million years.

Though the original ecology of the T'zeche is unknown, it could be assumed that they evolved on their ring world in response to the pressure of that dying ecosphere, where forests would have become less prevalent, and a drier climate would have dominated.  once they left their homeworld, however, the T'zeche embarked on a long history of terraforming worlds, whatever their original form, into lush Gaian planets capable of supporting themselves and those creatures which they brought with them.  As such, they came to inhabit a wide variety of ecospheres, with only arctic conditions being passed by.

They were apparently a hardy species, with toughened skins and a rather dense skeletal structure.  This brought about an initial image of the T'zeche as a race of fighters, a view that has since been regarded by the scientific community with a fair amount of disdain.  However, their dense construction is something of a mystery;  if one assumes that the Dunwalli ring worlds were universally constructed to provide 0.8 gravities, then the T'zeche should have been constructed more lightly.  Some scientists believe that this is proof of at least one instance of variation in the Dunwalli constructions, and that the T'zeche were from a higher gravity ring world.

The most telling item was a habitable world, a planet roughly the size of Mars, sporting a rich biosphere.  A number of items made this world, later named Würm because of the major ice age that is presently occurring, stand out as being unusual.  The lack of any moon meant that the planet's axial tilt changes chaotically over millions of years.  Such an occurrence would make advanced life nearly impossible.  There also was a near total lack of geological activity, and a resulting low level of greenhouse gases in the atmosphere, such as carbon dioxide.  Gaian planets are kept much warmer by the presence of such gases, and indeed this may have been the reason for the growing ice age.  In essence, this planet should never have been a living world.

While the determination that Würm was a terraformed world would come much later, after the initial scientific colony had been established, ruins on the surface of Würm were very swiftly found.  While geological activity on Würm had never been high, even with modifications made by the terraforming process, it was sufficient to bury or otherwise remove building and city structures left behind by the T'zeche.  However, one region, obscurely named Intempesta Nox by the colonists, was discovered to be filled with the artificial structures of the species.  Eroding out of a former lake bed, the sediments that had come to cover this city had never experienced the typical compression and pressures that would have come with a truly active geology.  As such, entire structures were found to be quite intact, having been well preserved in the anaerobic environment of the lakebed silt and mud.  It is from these ruins that the League's current knowledge of the T'zeche comes, largely in the form of actual bound "books" with diamondoid pages and lightly engraved surfaces.  While computer systems have been found, their systems and power sources have long since succumbed to the elements.

Most remarkable, however, were the associated bone beds.  Determined to be actual T'zeche remains, there have been found literally tens of thousands of individuals jumbled together, many of the preserved bones jumbled together.  Found just outside of Intempesta Nox, it is theorized that either this was some sort of mass grave, or it was a natural disaster which doomed these many individuals.  However, on a world that has been terraformed by the masters of the trade, it is difficult to imagine what sort of accident on a world might possibly occur, and which would overtake so many individuals at once.  The alternate possibility is then left the more likely one;  the implications of a mass grave, however, are quite chilling.

There are other remains to be found in this system, as well.  A number of half completed or time-ruined megastructures, primarily habitats remarkably similar to Bernal Spheres and averaging a diameter of 10 kilometers, can be found in solar orbits, with one example on a ballistic course out of the system, presumably after a close encounter with the sun.  But most remarkable is the next planet outward, named Günz, which has the blatant visual evidence of the de-orbiting and subsequent impact of an orbital ring megastructure.  Girdling the equator is a series of mountains and craters, the remains of the ring itself after it had impacted at varying velocities with the surface.  No remains of T'zeche have ever been discovered here, leading to the conclusion that the ring collapsed due to a cessation of upkeep.  The world had, in short, been abandoned.

Preserved evidence on Würm is sparse in regards to why the T'zeche disappeared.  But it is apparent that they did so over a span of several thousand years.  If so, then there may simply have been a sort of cultural or racial senescence.  The T'zeche may have finally expanded as far as they thought necessary and settled down on the many worlds that they terraformed and colonized.  In the end, these disparate population centers may have simply died out as the millennia wore on.