Every form of life on our planet — from species that swim in the water to those that
soar through the air, from the largest land mammals to the smallest of insects — all
these creatures and their patterns of life are, in some way or another, determined by
the same, invisible force: gravity.
Earth’s gravitational pull influences the parameters of animals’ body plans, maximum
size, and behavior — often limiting the ways in which life can evolve.
But an earth-like level of gravity isn’t a constant through the universe.
Imagine a planet where gravity is much, much weaker than it is on earth.
What kinds of fantastical forms of alien life might evolve?
This speculative hypothetical is the inspiration behind the fictional alien world of Anu, a
creation of the talented artist Sam Vilasboas.
The organisms on Anu have evolved into very different forms than what could feasibly exist
on our own planet.
Vilasboas is an awesome worldbuilder, often creating entire diagrams going into the hypothetical
science behind the forms of low-gravity life populating planet Anu — including an entire
taxonomy chart showing how the various aliens we’ll be exploring in this video are related
to each other.
If you want to check out more of their work, as usual I have links to them in this video’s
description.
So, for this entry into the archive, we’ll be taking a documentary-style deep-dive into
this incredibly detailed low-gravity world.
Not surprisingly, the most fantastical forms are in the air, but let’s start where life
often begins — under the waves.
The small, rocky planet of Anu doesn’t have much water compared to earth.
But like on our own planet, multicellular life likely began within these depths.
Starting at the base of the Anu evolutionary-tree, we have the very simple Necroviscera, jellyfish
like organisms with emaciated forms that swim in the low-pressure depths.
These lightweight organisms are small and relatively uncomplicated, but they’re basal
to many other more fantastical lifeforms on the planet.
Moving up the evolutionary tree, we have these “fish-like” lifeforms present in most
bodies of water on Anu.
Ingentriadix are a basic example of such an organism.
Thanks to the semi-universal nature of hydro dynamics, the artist imagines these lifeforms
aren’t much different from fish on our own planet — although they don’t have to worry
as much about water pressure in the depths thanks to the lower gravity.
Feeding on organisms like Ingentriadix are species like the Litzacrista, early predators
about the size of a tiger shark.
They usually hunt alone, ensnaring prey in their four-part jaws — which the artist
imagines most species on planet Anu have due to a common ancestor.
This is another species which lives in the low-pressure depths, drifting along on silent
fins.
On land, organisms become more complicated, and start to truly adopt unfamiliar forms
which take advantage of the low gravity.
This spindly group is the Flammanasus — organisms that likely wouldn’t be able to stand up
on our planet, but move just fine in Anu’s gravity.
The artist imagines they travel in packs, like you can see here along one of Anu’s
many beaches.
In this image, a young Flammanasus picks a senseless fight with another pack member to
show strength.
And according to the artist, loses quite badly.
In another image, two Flammanasus walk along the muddy bank of a river, looking for a high
spot to warm themselves in the sun.
Temperature regulation is critical to Flammanasus survival.
The artist imagines that specialized organs all along their bodies accumulate and burn
fats, creating heat when needed.
The Flammanasus use this adaptation in a specialized manner: they can heat the air stored in the
space in their upper jaw.
At night, Flammanasus — which can see in infrared light — use these flashes of heat
to communicate with one another, as this image demonstrates.
A larger land-dwelling organism is the Dracocentaurus — a species with legs too spindly to support
a sizable body on our planet, but whose limbs are effective in its own low-gravity environment.
These omnivorous creatures have evolved two long, pointed limbs for spearing prey, which
superficially resembles the insectoid claws on various types of mantises.
Despite their fearsome appearance, the large Dracocentaurus are a social species with some
signs of early intelligence, with packs exhibiting significant social complexity.
Even larger still, and less cunning, are the gargantuan Brachicornibus.
These mighty grazers take full advantage of the low gravity, growing over three times
the size of an earth elephant.
Their strange, antler like front limbs are a powerful form of defense, making them essentially
untouchable.
But the Brachicornibus aren’t the largest organisms on planet Anu.
That distinction goes to the Necrocampus Continentale — which at a glance just look like a field
of savanna grasses, but are actually a single massive lifeform.
A cross-section reveals these ‘grasses’ are just the top part of the huge, cell-like
structures that makes up these curious organisms.
The artist imagines some of these cell networks form whole biomes of their own, and are so
large they can be seen from space.
In the places where two of these lifeforms meet, elevated areas form — which makes
the organisms almost analogous to living tectonics plates.
A genuinely unique speculative concept.
But the land isn’t the only place to take advantage of Anu’s low gravity.
In the vast skies above this small planet, a truly unique ecosystem has formed.
The skies of Anu are like an aerial ocean, with lightweight organisms gliding along on
fins similar to how creatures move through the seas on Earth.
Near the bottom of this aerial oceanic food-chain are the Endocrura, lightweight organisms whose
size allows them to be easily scattered by the winds.
Most live within the equatorial forests on Anu, and can display mesmerizing colors like
tropical birds on our own planet.
Other Endocrura have adapted to the cold lands north of the equator, like this fuzzy, sleek
species whose color helps it blend in with the snow.
Often called ‘wolves’ due to their pack hunting behavior, these species can both leap
great distances to catch prey and scavenge on the ground — although they aren’t true
fliers like their relatives.
Higher up in the atmosphere, larger organisms take flight.
This is an example of a Foliopalum, a brightly colored herbivore that sails along on three
sets of paddle-like wings.
These colorful noodles eat leaves and giant spores which are sometimes released into the
air by specific plants.
The idea of flying spores reminds me of dandelion seeds, which, as I’m sure you know, can
also become airborne on gusts of wind.
But where there’s herbivores, there are carnivores.
The Enodoptera are a group of large equatorial predators which the artist has nicknamed the
‘air-sharks.’
One specific species is the Orbualus — a high-altitude ambush predator that specializes
in capturing low flying prey.
Their keen eyes allow them to scan for prey far below them, then dive down at high speeds
and pierce their target with their front limbs.
Like birds on earth, Enodoptera will sometimes rest on the trunks of tall vegetation in between
periods of searching for food, which can be a draining ordeal.
Here, a group takes a break after an unsuccessful hunt, looking for some shade where they might
hopefully get some rest.
Another type of Enodoptera are the Stellapulmo — snake-like predators that fly along the
riverbanks of a region called Eden Valley — a biome surrounding the largest lakes
on the planet Anu, and one with the highest concentration of biomass of any region.
In this lush environment, serpentine Stellapulmo, flourish in large numbers: catching small
creatures when they spot them from above.
A larger Enodoptera are the Bia-lavis-qualus, lion-sized aerial predators that glide in
packs through the skies above mountainous regions.
They hunt and eat any terrestrial animals on the mountain ranges that they can take
down, which likely includes most species of the aformentioned Flammanasus.
But there are some organisms in the skies far too large for most predators to consider
hunting.
The Abzulong — which actually fall into the Enodoptera classification despite being
herbivores — have long, narrow bodies which wouldn’t be able to take to the air in earth’s
gravity.
On Anu, however, the Abzulong rule these clear skies.
Or at least, mostly.
In truth, even the massive Abzulong aren’t completely safe.
Not when the Crommus Rex is on the prowl: the biggest flying creature in the skies of
Anu.
These giant organisms almost resemble small airplanes — and consume anything they can
fit in their mouths.
Which, as this diagram shows is quite a lot — as the artist imagines the Crommus Rex
has not a four, but a six-part jaw that can fit around almost anything.
A true apex of the low-gravity ocean-like skies.
The unique low-gravity lifeforms of planet Anu are just one speculative interpretation
of what life on a planet with lower gravity than our own might look like.
If you like exploring this fictional world, consider supporting Sam Vilasboas by visiting
the links below.
There are other species of Anu on their page which I didn’t get to here, so check those
out if you’re interested.
Also, thanks for watching.
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See you in the next video.