The ArcBuilder Universe


TimeLine of the ArcBuilder Universe


The Archaic Galactic Era

1.35 billion to 390 million years ago


1.35 billion years ago:  The earliest known examples of the Dunwalli presence as a space faring polity.  With an already magnificently high level of technology, their culture and societies had certainly already been present within the Milky Way for some time.

1.2 billion years ago:  Single celled eukaryotic organisms develop meiosis and sexual reproduction.  This innovative method of transferring genetic codes down to the next generation, while still primitive, hastens the diversity and evolution of life forms.  Among these new early forms are the red algae.  Simplistic multicellular forms also begin to diversify.
1.06 billion years ago:  The earliest forms of true fungi evolve.  While no fossils have been discovered, their presence is inferred from a comparative basis of the rate of evolution of closely related groups.

900 million years ago:  The earliest choanoflagellates evolve.  Living in colonies, they show the first signs of having cellular specialization for specific bodily tasks.  While these creatures are the direct ancestors of the first sponges, they are also the direct ancestors of all animal groups on the planet.

720 million years ago:  The Sturtian Glaciation, a snowball Earth event, takes hold of the planet.  It is a severe climatic episode, With the entire surface of the planet falling under the ice sheets.  Even at the equator, seasonal temperatures rarely exceed the warmer temperatures found in modern day Antarctica.
660 million years ago:  The Sturtian Glaciation comes to an end relatively swiftly, as atmospheric carbon dioxide levels, produced by volcanic activity, create a level of global warming that thaws the planet.
650 million years ago:  The beginning of the Marinoan Glaciation, a snowball Earth Event.  This was perhaps the most severe such episode that the Earth had ever suffered, with ice sheets of substantial thickness reaching down to the equatorial regions. 
635 million years ago:  The Marinoan Glaciation comes to an end.  In concert with this, the earliest forms of Ediacaran biota  evolve, being primarily enigmatic tubular and frond-shaped, largely sessile organisms.

600 million years ago

  • The earliest sponges evolve.  These were extremely primitive multicellular creatures, possessing partially differentiated tissues.  Indeed, sponges remain the oldest extant animal phylum on Earth
  • The planetary oxygen level has increased to the point where an ozone layer begins to form, protecting the surface from solar radiation and opening terrestrial colonization by the earliest plants and animals.
  • The latest known presence of the Dunwalli species.  A Galactic level civilization, it is likely that they existed well past this point, though their ultimate fate remains unknown. 
580 million years ago:  The cnidarians evolve.  These are the earliest creatures to possess nerves and muscles, allowing for independent movement.  They are also the first to possess a definitive form and shape, largely defined by radial symmetry.  Specialized nerve clusters also begin to develop, capable of detecting external light levels.  These are the first eyes.
575 million years ago:  The Avalon Explosion.  This is a massive expansion and radiation of the Ediacaran biota, and represents the first major diversification of multicellular, complex life forms.
550 million years ago:  The evolution of flatworms sees the first animals appear who have brains and simple bilateral symmetry.  At the same time, the earliest known comb jellies, corals, and anemones appear.
542 million years ago:  The last of the Ediacaran biota go extinct, supplanted by creatures evolving during the Cambrian Explosion.  It is clear that the extinction was caused by this new radiation of life, and it was the resulting animals which lead to nearly all modern forms of animal life on Earth.  It is also during this period that fungi begins to colonize the land, along the margins of tidal bays, rivers, and lakes.
530 million years ago:  Several species of early chordate predecessors evolve, most notably being the species Pikaia.  Some two inches in length on average, lacking a well-defined head, it swam in the Cambrian seas among the other residents of the Burgess Shale.  Its movement was much like that of an eel, aiding it in its preferred bottom-dwelling environment, where it on organic debris within the mud.
510 million years ago:  The first cephalopods evolve, along with the first chitons.
505 million years ago:  The first vertebrates evolve.  Represented by the ostracoderms, these are jawless fish with cartilaginous inner skeletons.  Generally these were bottom dwelling creatures, feeding off of plants or other biological matter.  While primitive, they would eventually lead to the more advanced Osteichthyes, or boney fish.
480 million years ago:  The first jawed fish evolve.  The much more efficient jaw first evolved from the already present gill arch, and allowed these creatures to expand their diets to fish and other prey animals, increasing metabolism and evolutionary success.  These early jawed fish were represented by the Placoderms, fish with armored heads and thoraxes, the rest of their bodies being either naked or scaled.  Despite this innovative evolutionary advancement, the Placoderms left no living relatives.
470 million years ago:  An asteroid approaches the Earth and is broken up by tidal stresses.  The fragments rain down on the planet, in a rough line that stretches from modern Sweden, over the polar regions, and to modern Iowa.  The event affects the climate quite drastically, but it also inspires the Great Ordovician Biodiversity Event, a diversification of life across the planet as the many forms attempt to adapt to the fluctuating climate.
460 million years ago:  The earliest known members of the eurypterids appear.  Commonly called sea scorpions, they represent a formidable group of marine predators, which diversified greatly during their evolutionary history.  The earliest known example, Pentecopterus decorahensis, was already a well developed and large species, indicating that as of yet undiscovered ancestral forms had already existed.
434 million years ago:  The first primitive plants appear on land.  Having evolved from shore-dwelling green algae, a symbiotic relationship with fungi is started, aiding in their spread across the planet.
420 million years ago:  Some of the earliest land animals appear, taking up residence in the thickening, but still short "forests".  Among them are the trigonotarbid arachnids and land scorpions.  In the oceans, the first sharks appear, although their appearance is quite different from their later, more streamlined look.
407 million years ago:  The first definitive insect fossils come from this time.  The species, Rhyniognatha hirsti, possessed features consistent with winged insects.  This infers that the true origin of insects lay much further back in time.

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The ArcBuilder Universe is a science fiction project established, authored, and copyrighted ©
by John M. Dollan 2002-2016
This page first uploaded in February 10, 2016
Most recent update for this page February 13, 2016