"The Tyranids are without doubt the most rapidly evolving creatures in the galaxy. The Magos Biologis of Mars have observed developmental DNA leaps between broods originating from different hive fleets that would take other beasts millions of years to achieve. It appears that the Tyranid "Norn Queens" or primogenitor organisms aboard the Hive Ships are capable of modifying their progeny in response to the environment and life-forms they encounter. Newly harvested genetic codes are assimilated, the prey's defensive measures are examined, and improved creatures are bio-engineered to overcome that resistance. Over time, the myriad improvements to the hive fleet's gene pool are melded with others, strengthening the entire race."
- —Extract from Magos Biologis Alder Garrick
Variant Imperial icon used for identifying Tyranid hive fleet activity.
A Norn-Queen, also sometimes referred to as a Splicer-Beast, is the highly intelligent Tyranid bioform that leads the great Tyranid swarms and directs the evolutionary paths they take as they adapt to each new environment or tactical need.
The Norn-Queens live upon massive Hive Ships in huge chambers at the centre of the hive fleet and ingest genetic materials. They then churn out through asexual reproduction all the countless types of bioforms that make up the Tyranid hive fleet. All Tyranids have genetic links back to a Norn-Queen, as the only way for Tyranids to reproduce is through this cloning technique. Unlike so many of the other Tyranid bioforms, Norn-Queens are self-aware beings.
The Norn-Queens are constantly producing new biomechanical Tyranid organisms, bio-weapons, and voidships from a target planet's recently consumed bio-mass. The Norn-Queens control the fleet and send orders to Tyranid synapse creatures on an invaded planet. The synapse creatures then retransmit those orders through the Hive Mind to the lesser Tyranid bioforms.
The Norn-Queens control the evolutionary course of the Tyranid swarm. Upon arrival at a new target world they intend to strip of its biomass, the Tyranids disgorge the "Alpha" swarm of bioforms. The Alpha swarm contains the genetic material of that particular hive fleet's ruling Norn-Queen. These creatures then relay telepathic information to the Norn-Queen on the new world's environmental conditions and battlefield requirements, which spawn the second and subsequent generations of Tyranid bioforms, sometimes with tens of thousands of casualties in the collection of the data.
Capture of an Alpha wave Tyranid bioform can lead to the creation of a deadly neurotoxin which can directly affect the Norn-Queen, as was done by the Ultramarines during the invasion of Ultramar by Hive Fleet Behemoth. When a Norn-Queen is killed, the psychic backlash of its death in the Hive Mind -- approaching level Gamma 12 in intensity -- causes nearby Tyranid Hive Ships to calve, creating more Norn-Queens within their interiors. This is an instinctual survival mechanism of the Tyranid species that is known as the "Hydra Effect," and is the reason why when a hive fleet is defeated, it can quickly form splinter fleets that eventually become larger than the original.
The forces of the Imperium to date have encountered only a single Norn-Queen during the Battle of Tarsis Ultra. A biological plague created by using a Lictor's DNA as the foundation for the pathogen was injected into the Norn-Queen by Captain Uriel Ventris of the Ultramarines 4th Company. This disrupted the Hive Mind's coherency and the Tyranid creatures reverted to overly aggressive, animalistic behaviours, turning upon one another in an orgy of cannibalism. This action also crippled a tendril of Hive Fleet Leviathan.
Quick Answers
What role does the Norn-Queen play in the evolution of the Tyranids?
How does the Norn-Queen modify her progeny in response to their environment?
What is the significance of the Norn Emissary in the Tyranid hive?
What is the size of the Norn Emissary compared to other Tyranids?
Tyranid Reproduction
A Tyranid hive fleet's Norn-Queens require a constant supply of genetic material and undifferentiated nutrient bio-mass (a slurry of organic and inorganic chemicals including minerals, proteins, nucleic acids and carbohydrates) in order to clone or genetically craft new Tyranid bioforms. This bio-mass mainly consists of the slurry formed in Reclamation Pools on a target planet's surface that are pumped up into the orbiting Tyranid Hive Ships through massive Capillary Towers created by Tyranid bioforms.
Genetic material is also supplied directly to the Norn-Queen by other Tyranid bioforms, such as the Coffin-Crawlers. This raw material is pumped into the great jaws that are located at the top of the Norn-Queen and then synthesised into a new bioform design by the Norn-Queen's genetic shredder organs. The disassembled DNA structures form a biochemical "gene-bank" of millions of different genotypes that can be used to "assemble" a new organism using the biomolecular machinery of the Norn-Queen's metabolism. This organic genetic engineering mechanism is very similar to a Terran mammalian immune system in that it "remembers" the biochemical structure of every DNA sequence it has absorbed just as an immune system can biochemically "remember" every pathogen it has ever encountered.
These absorbed DNA sequences provide the raw material for splicing and mutation from which new Tyranid creatures are created. Once a type of bioform has been engineered to meet a purpose determined by the Norn-Queen, more bioforms of the same type can be cloned by all the other Norn-Queens of a given hive fleet.
The Norn-Queens are capable of bringing forth new Tyranid bioforms in a variety of different ways, each designed to ensure maximum reproductive efficiency. Most Tyranid bioforms are born live as tiny, hideous larvae or as eggs that must be nurtured further before they hatch and rapidly grow into their mature, adult forms.
Clusters of Tyranid eggs spill from the rows of ovipository orifices along a Norn-Queen's flanks, while nutrient fluid-filled depressions on the massive alien mother's upper surface writhe with maggot-like larvae. Fetal amniotic sacs for other bioforms hang like ripe fruit from corded umbilicals, while huge Teleporter Worms burst from incubator pouches on the Norn-Queen's sides to allow newborn bioforms to be quickly moved around the vessel for easy deployment.
The simplest Tyranid bioforms often emerge in their fully mature state and then are directed to begin serving their expected purpose by the horde of small Tyranid worker bioforms whose only purpose is to feed and maintain a hive fleet's Norn-Queens.
Sources
- Advanced Space Crusade Rulebook (Board Game)
- Codex: Tyranids (4th Edition), pp. 4-5, 17-18, 27
- White Dwarf 146 (UK), "Space Fleet: Tyranid Hive Fleets - The Hivefleet," by Andy Chambers & Andy Jones pg. 21
- Warriors of Ultramar (Novel) by Graham McNeill