To'ul'h

To'ul'hs are a sapient, technological species in the Orion's Arm science fiction universe, native to planet To'ul'h Prime in the H'tat'sa'thoss Sytem. They are the first intelligent extraterrestrial species ever to be contacted by Humanity in-universe, around the 58th century CE.

Etymology
To'ul'h (plural To'ul'hs) is intended to be a genuinely alien name and not a construct from words of any human language.

The word's pronunciation is not specified.

Anatomy and physiology
A To'ul'h possesses both bilateral and tetraradial symmetry, though the last one is approximate. Much like Earth tetrapods, a To'ul'h has bilateral symmetry, a bony skeleton and four limbs; though the cardiovascular system is much closer to that of an echinoderm.

A To'ul'h's mass is anywhere between 40 and 100 kg, varying with regional varieties, with a typical adult mass of 70 kg for males and 63 kg for females.

The braincase is located in the central dorsal part of the body trunk, from where it innervates the limbs and receives input from sensory organs. Having a thin and light skull, fat is accumulated around to absorb mechanical shock. The central position of the skull might indicate that a To'ul'h lacks a vertebral column.

The frontal dorsal part of the body contains three bat-like ears that a To'ul'h uses for echolocation. The central ear is powered by a lung-like organ. Hardly-noticeable eyespots on the dorsal surface allow a To'ul'h to detect light but not form an image out of it.

The four limbs look very much alike, organized into frontal and hind pairs. However, the hind limbs are stronger, heavier and keen at jumping. The fore and hind limbs are connected with retractable patagia, providing the ability to glide. Certain birth defects can render a To'ul'h unable to fly.

All four limbs are segmented into three and end with hand-like structures. Each hand has six fingers and two thumbs, thus making a To'ul'h octodactyl and giving the impression that land locomotion is digitigrade. Unlike human hands, the eight digits are arranged symmetrically.

Being a heterotrophic organism, a To'ul'h possess an internal digestive system. It begins with sideways-opening mandibles between the forelimbs and ends with an anus between the hind limbs, both being ventral openings. The stomach and intestines are located in the ventral central part of the body, protected by fat like the braincase. Mastication is carried out by a gizzard on the forepart of the stomach rather than by teeth in the mouth. After nutrient absorption in the intestines, liquid waste and excess salts are excreted through the anus.

A To'ul'h has three lungs, with the two being responsible for respiration being located between the pairs of limbs. These two book-lungs are independent and have one opening (spiracle) to both dorsal and ventral surfaces. Breathing is rather complex. With normal exercise, air just flows between the dorsal spiracles, helped by limb movement. With heavy exercise however, air can be pumped by opening endings in both surfaces in turns, providing greater oxygen uptake and cooling at the expense of greater hydration.

Blood composition and appearance is never specified, though the circulatory system resembles that of an Earth echinoderm, pumped by three hearts. Like humans, the cardiovascular system is divided into pulmonary and systematic systems. However, instead of having a single, chambered heart; two hearts are connected to the lungs, with another one pumping oxygenated blood into the body.

A To'ul'h exhibits no external genitalia and is either male or female, being a sexually-reproducing dioecious species. The genitalia are comparable to the pedipalps found on spiders, and fertilization is internal.

Environmental requirements
Taxonomically, To'ul'hs belong to the hyperthermophile superkingdom, a group of organisms with an optimal physiological temperature of 135 ºC. Without some form of conditioning (such as clothing or hydration), a To'ul'h dies at temperatures cooler than 100 ºC or higher than 150 ºC.

Adapted to an atmospheric pressure of about 60 atmospheres, they can nonetheless withstand short-tem exposures of as little as 10 atmospheres and longer terms exposure of 50 atmospheres. Earth-like pressure is immediately fatal, resulting in bodily fluids boiling away. To'ul'hs are aerobic like humans, but die with an oxygen concentration lower than 7% or higher than 15%.

Drinking pure or alkaline water has a more fatal effect in To'ul'hs than in humans. They can however, drink from fresh moderately acidic (pH 4) to hypersaline water, excreting excess salt in the last case.

Earth-like sunlight intensity can blind their eyespots and ultraviolet radiation produces severe burns.

Evolutionary history
To'ul'hs and all life on their homeworld had a common, prokaryotic, single-celled ancestor roughly 2 billion years ago, while Earth was having its Orosirian period. Some point after that, that common ancestor diversified into three different prokaryotic superkingdoms that would eventually and independently create multicellular eukaryotic life.

One of these multicellular eukaryotes evolved into crinoid-like sessile organisms with tetraradial symmetry, which would eventually give to the dominant animal phylum to which the To'ul'hs belong. Roughly 400,000 years before humans first landed on the Moon, modern baseline To'ul'hs appeared, making them twice as old as the Homo sapiens sapiens.

Senses
A To'ul'h's primary sense is based on sound. Three large bat-like ears are used for this. A To'ul'h can just listen and still get a lot of information about a place. This passive form of sonar can help a To'ul'h image a low-resolution picture of something up to one kilometer away.

However, the central ear can produce ultrasonic chirps in 50-200 kHz range to define features as small as half a millimeter within a 20 meter radius; this is named echolocation or active sonar.

Besides, the forelimbs contain organs that generate and sense weak electric fields within the range of a meter, constituting a To'ul'h's second most important sense: electroreception. On land, it allows detection of distant storms. It is more helpful on water or mud than on land though, since nearby creatures can be detected this way. On land, a To'ul'h is able to detect the magnetic field of the planet and use it for orientation (magnetoreception).

Touch is very sensitive, especially on their hands and the overall ventral surface. To'ul'hs can also taste with their hands, in order to distinguish between edible and poisonous saprophytes or track prey. Smell is also very acute.

Arguably, their least sophisticated sense is that of sight. With a dark and noisy environment, hearing resulted more useful than seeing. Eyespots do allow a To'ul'h to perceive light, but not form an image.

Psychology
Despite all the differences between humans and To'ul'hs, there are simmilarities in developmental history and reproduction with a profound impact between both species understanding each other's psyche and society.

However, having sonar and electroreception has a profound influence in their method of thinking. Not having sight distances To'ul'hs from understanding humans, bringing them closer to getting literary concepts of other blind species, such as the ancient space-faring Muuh.

To'ul'h metaphors are based on the properties of sound, since light is not something positive and are afraid of occassional clear patches formed on the sky in the same way a human might fear lightning. In fact, their version of Heaven is that of a warm, damp and dark place, while the human vision of it as something fresh and brilliant embodies their vision of Hell.

They are as capable of concentration and rational thinking as humans, which is necessary to understand science and invent technologies that rely on patient planning rather than eureka moments.

Communication and language
Perphaps surpringly, To'ul'hs communicate using sound despite their noisy and astoundingly loud environment, speaking with their ventral respiratory openings. However, their environment would mean no impediment at all if the are able to produce sounds with a higher pitch. Since their To'ul'h can produce ultrasounds for echolocation, this is likely the case.

For millennia, To'ul'hs have had means for recording history and enabling long-distance communication through writing. Letters, ideographs and glyphs are carved rather than written however, in order to be read by active sonar or touch. Anyway, To'ul'h writing resembles anything from runes to braille.

Though there are or have been hundreds of languages, the common language is To'ul'ho'lo'ss, which was already in existence in existence 30 millennia before present. Strangely, though To'ul'ho'lo'ss names can be translated as written words in Latin characters, many of them are unpronouceable in English. Names such as H'th'hh, H'sh'l'ho'th'th or Ho'th'hss'lho exemplify this. Furthermore, what the apostrophes (found in virtually every To'ul'h-related word) mean is never explained.

Culture
Though limited to a sole planet before contacting humanity, To'ul'hs have created a vast range of cultures based on radically different worldviews, due to their long history. Analogs of Capitalism, Christianity, Confucianism, Fascism, Hinduism, Humanism, Marxism, Neoplatonism, Stocism and Taoism have all at least emerged once among a To'ul'h community, as well the in-universe ideologies of Etodism and Negentropism.

History
Certain portion of To'ul'h history can be divided into three epochs, marked by the catastrophic eruption of Mount 'Thass'thon' and the contact with Terragens, shown as followed.
 * c. 400,000 BT - First anatomically and behaviorally-modern To'ul'hs speciate from their ancestors, beginning to live as bands of semi-nomadic foragers.
 * c. 95,000 BT - To'ul'hs have agriculture by this time, along with tools made of obsidian and ceramic.

Pre-eruption (72,500 BT to 37,500 BT)

 * c. 72,500 BT - The Necropolis Civilization (also known as the First Ones) become the first society to emerge on To'ul'h Prime. Members of this civilization use the psychotropic landsponge known as tho'rahl'shothan for recreational purposes, though not possibly being the first ones to do that.


 * c. 37,500 BT - Supervulcano 'Thass'thon' erupts, resulting in the death of tens of millions of To'ul'hs in the most destructive event their history.

Post-eruption or Pre-contact (37,499 BT to 4010 AT)

 * c. 30,000 BT - The oldest written recordings in To'ul'hoss language are made.
 * 25,883 BT - Beginning of the To'ul'h Calendar, 'Ha'ts'ul in To'ul'hoss language.
 * c. 7500 BT - The most recent skywhale-hunting cultures end.
 * 3831 AT - Terragens discover the To'ul'h through the MPA ship Fortunate Cloud, but decide to observe them instead of revealing themselves.

Post-contact (4011 AT onwards)

 * 4011 AT - Terragen-To'ul'h first contact is made. Shortly after, the To'ul'hs are invited to join the Terragen civilization, beginning a renaissance era on their homeworld.
 * 4211 AT - The first intra-To'ul'h conflict occurs, between the Spacer and Homeworlder factions.
 * 4300 AT - To'ul'hs have already integrated Terragen technology and ideas to their culture.
 * 4318 AT - First humans to ever be killed by To'ul'hs. The incident takes place on the Eithne habitat orbiting To'ul'h Prime.
 * 4328 AT - The Homeworlder faction expels the Spacer faction.
 * 4511 AT - Ideological tensions rise between the Spacer and Homeworlder factions, resulting in the major intra-To'ul'h conflict since Terragen contact, the Spacer-Homeworlder Wars.
 * 4645 AT - The Spacers' final assault on To'ul'h Prime is intercepted by transapient O'hoth'so'toh, also known as Smoking Mirror, who is affiliated with the Caretakers. He declares To'ul'h Prime under his sovereignity, establishing the current administration.
 * 4720s AT - Nearbaseline To'ul'h H'th'h'h begins to live in the megastructure of Kiyoshi, experimenting the nomadic philosophy of the Vagabond Way.
 * 4750s AT - H'th'h'h converts into Islam and begins to passionately study the Qur'an for months.
 * 4793 AT - H'th'h'h arrives and pilgrimages on Medina, a Terragen Islamic world, to explore and learn in the virtual reconstructions of the Mecca, Medina and Jerusalem.
 * 4912 AT - After preaching to other To'ul'hs, H'th'h'h has developed a sizable following and expose their plans of terraforming and colonizing a world with Muslim To'ul'hs to the Stellar Umma.
 * 4998 AT - H'th'h'h and his followers arrive at their target system for colonization, the third world of the H'sh'l'ho'th'th System. The Stellar Umma provides the colonists with the needed mediums to accomplish terraforming.
 * 5042 AT - H'me'ch has been terraformed for To'ul'h habitation and is subsequently settled by 30,000 To'ul'h colonists, 20,000 AIs and 500 xenosplices.
 * 5900s AT - Many non-To'ul'hs begin to visit H'me'ch.
 * 6000s AT - H'me'ch is renowned by the Stellar Umma for its philosophers and culture.
 * 6001 AT - H'th'h'h ascends to the first toposophic level, effectively becoming a post-To'ul'h.
 * 6833 AT - H'th'h'h disappears from the Stellar Umma, perphaps to continue to preach other extraterrestrial factions about Islam.
 * 8753 AT - H'me'ch is annexed to the Wormhole Nexus.

Future events

 * 11053 AT - The To'ul'h Calendar completes its first Great Year. Apocalyptic or historical events happen at this time, according to some cults.