Le'ma

**Le'ma**, also known as **Tau Ceti f** is the fifth planet from Tau Ceti and the only object in the Tau Ceti system to naturally support life. It is the densest planet in the Tau Ceti System and the largest of the five terrestrial planets. It is the homeworld of the K'lerin.

According to radiometric dating and other sources of evidence, Tau Ceti f formed about 5.8 billion years ago. Le'ma's gravity interacts with other objects in space, especially Tau Ceti and the planet's three natural satellites, To'ba, Yin'ba, and Va'ba. During one orbit around Tau Ceti, Le'ma rotates about its axis over 642 times. Le'ma's axis of rotation is tilted at 12 degrees, producing seasonal variations on the planet's surface that are more mild than those experienced on Earth. The gravitational interaction between Le'ma and its three large satellites causes ocean tides, stabilizes the planet's orientation on its axis, and gradually slows its rotation.

Le'ma's lithosphere is divided into several rigid tectonic plates that migrate across the surface over periods of many millions of years, and for the last 79 million years have produced a single super-continent. About 55% of Le'ma's surface is covered with water, mostly by a global ocean. The majority of planet's polar regions are covered in sea ice forming large glacial ice pack. Le'ma's interior remains active with a solid iron inner core, a liquid outer core that generates a sustained magnetic field, and a convecting mantle that drives plate tectonics.

## Life

Much like Earth, life emerged within the first billion years of Le'ma's history, as evident in its fossil record. Curiously, Le'ma did not experience any kind of life explosion equivalent to the Cambrian Epoch on Earth until 579 million years ago, lasting approximately 25 million years, giving rise to the theory of a Galactic Great Filter that hindered the evolution of complex life until relatively recently. In the history of the Le'ma, biodiversity has gone through long periods of expansion, punctuated by mass extinction events.

Prior to first contact the planet was defined by terran scientists to exist in the *K'lerisian* geological epoch, and the *Ornizoic era*, or the *Age of Birds.* While there is no genetic common ancestor between life on Earth and life on Le'ma, much less any relationship with Terran birds, the characteristics between the Ornizoic era of Le'maian life and terran birds and their status as the dominant terrestrial animals is difficult to ignore.

After a century of exploration, human and K'lerin scientists have a far greater understanding of Le'ma's fossil record and most date the origin of the Ornizoic at 44 million years ago. Like Terran birds, the bulk of Le'maian life include air sacs, hollow bones, while feathers (or cutaneous structures similar to them) and beaks are far more common than on Earth. Where they differ is that without exception the Le'maian "avian" life forms give birth to live young rather than laying eggs. These similarities has prompted many members of the International Union for Conservation of Nature to designate these organisms as Le'maian Dinosaurs. However, scientists specializing in the study of Le'Maian life generally do not use this phrase, as it implies a relationship with Earth life where none exists. The scientific name for the clade that the K'lerin belong to, which is the dominant group of "vertebrates" in the Ornizoic, is *Rhynchognathia,* or "beak-jaws".

The largest terrestrial "animals" on Le'ma exhibit a body plan similar to *Paraceratherium,* with animals akin to Sauropods being closer in size to a Giraffe. In the planet's single ocean, the largest creatures have hydrodynamically enforced body plans, and are remarkably similar to terran Cetaceans. The largest of these latter clade is the 38 meter long Greater Puffinwhale, only discovered by human or K'lerin in 2115. Ironically, powered flight does not appear to exist among the Rhynchognathia, and instead Le'ma's dominant clade of flying organisms belong to an "invertebrate" group that has independently evolved a means of supporting itself and breathing at large sizes. The largest of these flyers, known to the K'lerin as the Brasik, is roughly the size of a large albatross.

### K'lerin

*Main article: K'lerin*
As of 2160 an estimated 230 million K'lerin live on Le'ma and depend on its biosphere and minerals for their survival. K'lerin have only one coherent civilization on the planet, while the rest of the species lives as nomadic traders, and hunter-gatherers.