An Ultimate of Phylum Cynosur; these inhabit a dry, warm environment, and generally prefer modular biotech that resembles organic utility sand
The Ultimates were one of the earliest xenosophont races to be encountered by Terragens, in 4001, though due to the circumstances of their discovery they remained little known within the Terragen Sphere for over a thousand years. The Terragen name for this species group, 'The Ultimates', is a translation of the original term, which may be translated more literally as 'That Which Cannot Be Surpassed' (in the sense that their gengineering and bionanotech have reached an optimal level and further changes would be destabilizing).
Ultimates in their several varieties were discovered inside the so-called Black Acropolis dyson swarm, which was built by an even older and apparently extinct xenosophont race about 14.8 million years ago. The civilisation which created the Ultimates has left no other traces in the Terragen Sphere, and in fact may have arrived in a long-distance exploration probe which targeted the Acropolis from far outside the Terragen Sphere. For many years the Ultimates were believed to have been created by an unknown faction of Terragens, probably transapient in nature, but this appears not to have been the case.
The Ultimates were first contacted by an expedition of relativistic space adapted human colonists seeking to escape hyperturing dominance and establish their own civilization out in what was then the Periphery. By this time the Ultimates had become a cocooned culture that had lost their expansionistic desire. Some of the more adventurous Ultimates joined the humans and the other terragen clades that arrived in the following centuries to form the now transcended Gerkletoss civilisation. The remaining Ultimates isolated themselves in a number of biospheres, refusing to have anything to do with these crude barbaric newcomers. Some of the Ultimates who joined with the humans were later to populate a number of other star systems.
The Ultimates have a DNA-analog chemical complex which can mutate quite easily, but mutations almost always quickly degrade with hybridization. The result is that viable mutations are almost vanishingly rare, so the phenotypes of the different Ultimate phyla appear to have remained more-or-less unchanged for well over a million years. This trait is almost certainly the result of genetic engineering that occurred in the early history of their civilisation. It is quite possible, even likely, that none of the many different phyla resemble the original race that first created them. They communicate through pheromones, chromatopores, and complex body signals. Their bionanotech is quite sophisticated, but they lack any of the technologies developed by transapient entities.
Not only is the biotech of the Ultimates even more advanced than that of the Genen, but the tech from one clade is also incomprehensible to another clade, due to the different styles that evolved in isolation. Consider a plant/coral-based biotechnology in contrast to an insectile, mollusc-based or mammalian technology. Each Ultimate clade or phyle likes to approach and solve roughly the same problem in utterly different ways. A house might be a hollow tree, a chitinous cocoon or a mobile cone of fur. A computer might be much more different, and when one moves to the specialties of the different technologies the designs can be totally different. A sessile-style biotech, such as preferred by the Phylum Phyttinu (Lineage B), often involves having huge areas covered with plant-devices producing nutrient and controlling the environment, whilst the molluscan biotech used by Phylum Mhohrr usually involves the use of swarms of small beings doing jobs, whilst the mammalian biotech developed by Phylum GiiBuna adds social capabilities to all devices...
The Ultimates seem to be the remnants of a very ancient nomadic civilization, and retain the skills to construct large amat powered biotech worldships that move at no more than 0.1 c. Certain Ultimate clades have become integrated with the greater Terragen culture, often by forming a synthesis such as the Gerkeltoss civilisation which has spread out from the Black Acropolis in generation ships constructed by the Ultimates.
The so-called Ddgvko Culture is based on a symbiosis between MetaAllelle 5c Ultimates and the Vedokiklek.