30 November, 2021

PAART | MESOCAMBRIAN | CAMBRIAN | PART 2.5

Author's note

Phew! Gosh it's been way more than 1 year since Paart received any official updates - and I will do what's expected from me now, apologize for the time lost - due myself being shy as hecc to advertise the project still and do much about it, plus I just recently got out of my block and depression to finally do something about - hence why just recently this blog had any updates at all.

I must say that we aren't at the desired point yet, we are not even close to being ready like some others (Alien Biospheres or Wallace II for instance) which have more or less the same age 1~2yrs. BUT I think we have done enough to make a small diorama of the world so far, and it's a good thing that new members can even retroactively update the bestiary in the following updates.

I'm glad Porject Paart is not my salamander waterworld anymore, thanks to you all who stayed in the porject so far!

Without further ado, let's get into it.

wow, that's animals & stuff

Over the last couple of posts, we've discussed how the planet's climate heavily affected the ecosystem and animal "progress" - in which case we just accepted that things happened the right way so far in order for life to arise and develop.

We have always fast forwarded hundreds of millions of years at a time in order to get here, because life was generally simple and not a lot relevant to our topics. But now begins the real fun. Over the next updates starting from now, things will be "voted out" in our Discord server, we will generate alternate futures which will be chosen and built upon in the next update.

Because of difficulties regarding time notation, a second timescale will be used for life-related events, centered around 3840 PMA, or the Zero Year for complex animal life.

For all effects, the starting world is as follows...

THE CLIMATE

Mesocambrian Paart in Natural Colors

40 million years after the thawing of the land, which was marked by daily booms of cracking ice, the ancient riverbeds have evolved into bodies of water as large as the Mediterranean Sea. The new volcanic activity cycle has restarted the plate orders, so ancient mountains were now destined to be ground to dust into highlands and plateaus, as the world shifted and drifted towards the south pole.

The world has also been warmer for the stellar development of Vol, now 0,3% brighter, nearly +3 extra watts per square meter of irradiance - since the cracking of the ice, some clades have been developing across the tropical shores and continental shelves of the planet, which we will talk about in a bit.

The aftermath of these changes, generated a very hot world compared to Earth, with an average temperature of 30ºC.

The planet has developed a tight tropical belt where the regions are the hottest, the deserts reach a maximum daytime temperature of over 70,8ºC whereas the humid equatorial regions go to 50,5ºC. The overall high terrain is dry and colder at temperatures of 20-ish degrees.

Paart spins faster than Earth, it currently spins every 18 hours, so the atmospheric equatorial bulge of the planet is thicker than on Earth - which means that the ozone layer is also thicker around the equator. Hence why the land vegetation has first appeared in the equatorial regions of the continents of Germania, Alaska and Brittania.

The stabilization of the climate in the equatorial regions due the changes in soil albedo has created a great potential difference in the atmospheric systems, sucking water from the equator and raining it on temperate lands where the winds meet the massive polar vortexes.

We could state that Paart's cloud systems are formed by 3 belts (not to be confused with the atmospheric cells), the Equatorial Ascending Belt, the Temperate Descending Belt, and the Polar Streams.

The Ferrel Cells of Paart are truncated due the fast rotation and larger atmospheric mass, the Equator-to-Pole temperature difference also expands the polar cell just a little bit.


While on Earth the hot deserts are subtropical, on Paart due the truncated Ferrel Cell plus the thicker atmosphere and increased water vapor, an inversion zone is formed mid-Hadley, where high altitude clouds are denser, softening the insolation and balancing the humidity on the subtropical zones which are still relatively dry but not as much as they would on Earth, the descending currents impede further advancing of the vapor on the polar region, creating dry regions into the Ferrel Cell, and thus supertropical deserts, going further out, the polar front accumulates enough humidity (gathered from lakes and northern seas, in this case) for tundra and temperate forests to form.

Earth's cloud belt pattern derivated from a cloud map, blur on the left and zonal on the right

Paart's cloud belts pattern, the whiter the belt the more frequent the cloud formation

This extra cloud belt also makes the planet more reflective, and thus colder than it would be without it.

Despite not having any forests, nor any trees to be honest, so we can track the biomes from space - Paart has...

CHRYSOPHYTES!

Before any plant life existed on Paart, the oceans were rather acidic and lacking of magnesium minerals, so early xenoalgae resorted to the next element with similar properties, zinc - combination of photosynthesis and zinc makes Paart's algae 1,4x more efficient on average than if they used Earth-like pigments. This modified pigmentation (see Chrysophyll) is the root cause of their characteristic yellow-golden coloration, which they are named after.

Like on Earth, Paart's different photosynthetic life can be found redder the deeper into the disphotic zone, the filtering of red light is necessary so the plant absorbs mostly blue light which is more abundant at depths. On shallow waters, no complementary pigments are heavily favored so algae in general tend to be rather pure yellow - and by the time some colonies adapted to live on shores instead of open ocean, further protection from harmful sunlight were needed.

Euchrysophyta algal colonies

Some clades had over time developed two different ways to deal with excess acidity in the environment, either turn blue using calcium in their tissues to neutralized their internal media, or becoming red/purple with an anthocyanin layer under the vegetal cuticle - both which also served as some sort of plant sunscreen.

The first plantoid organisms to reach Paart's mainland were the anthocyanin users, the Ensarkophytes which quickly diversified into various moss and frond-like organisms.
Although the name suggests 'meat-colored', ensarkophytes have rich color wheel which depends on the specific soil chemistry.


High Iron and Alkaline soils lead to the non-expression of colored anthocyanin, which in turn also opens space for blue, green and cyan pigments to express themselves if there is also aluminum present - in near neutral soil the natural color of plants is towards purple.

WATER PLANTS
Artophytopsida by user Agen5

As far one goes on macroalgae of Paart, there is also a branch of more specific organisms, akin to Earth's plants if one may say so. Several divisions of waterplants saw their origins back in the Cambrian period, many which would mark forever the face of this planet.
The shallow coastal waters in which they live, rich in organics afloat and minerals in the soil leave them exposed to more UV rays than their yellow cousins of deep waters, and so their protective mechanisms are put into action, turning the sensitive parts tones of purple and red.

Amid the strategies we can from infer from the known flora of this period - there are plants which developed bulbous structures in their stems to better store nutrients and deal with algal blooms, which could easily destroy delicate structures like leaves, with these reserves at bay, one can easily regrow such structures, needless to say, such "bread-plants" (artophytopsida) are a feast for burrowing animals as well.
Deriving from the budding adaptation from artophytopsids, neoteny would have single-stem plants creating grass-like landscapes in the shallow seas, the xyphophytes, supporting only one leaf per individual, and almost as resilient as their bigger relatives.


LET THERE BE MOSSES!
The mosses of Paart are a subdivision of Ensarkophyta, called Yperychaliphytines (Hypery-shaly-fight-ynes), which translate to "thick-carpet plant", currently* divided into red mosses and black mosses, due their different contents of UV tolerance.
Those which would have spread across the planet as early as the Late Paleocambrian and Mesocambrian period when Paart used to have stronger winds - most mosses are Ypaithrosporopsids, which means that they reproduce by liberating spores into the wind hoping they reach the female reproductive stem, which liberates the meiospore in the wind after a 7-day life-cycle.

A coat of Ypaithrosporopsids over gravel would be very common sight inland in the Late Paleocambrian, by MO Valent

Many more groups of plants need to fully described, but here are some spoilers!


THE OCEANS!
At the same time ensarkophytes were developing around 3850 PMA, in the oceans, a boom of biodiversity had started to fill up the niches long abandoned by the Albabionts and the new environments in expanding shallow oceans.

The Metabionts had diverged in varied degrees of symmetry, which can be classified in bilateral, trilateral, and radial bodyplans.

For simplicity sake of this post, several dominant clades are featured, more detailed lineages and time-line are to be feature in a separate post or document.

GAMMAROIDS

Gammaroidea by user Agen5

Starting with trilateral bodyplans, we have Gammaroids - these are spiritually similar to Earth's starfish, however gammaroids are not broadcast spawners. Because gammaroids are mostly algae grazers, they live in nomad clustered groups that share a feeding-breeding ground, and thus looking for partners is more practical. Gammaroids have two eyes on the edge of each arm (six eyes in total) and can mate with 3 partners at the same time for their gonads are located in each arm as well, which all share a single stomach cavity apart from their internal structures. Their coloration is derived from both minerals and algae layer that usually grows on top of the calcite plates, their movements are possible via several pseudopodia on the underside of the animal, which also helps with cleaning of the mouth from sediment.


TRIBACULATES

Related to gammaroids, are the Tribaculata, or "three-sided sticks", alike gammaroids, they have a mouth in the center of the body, from where the arms extend, and the tip of the arms are located their eyes.

Unlike gammaroids though, they are basically flipped upside-down, their pseudopods are adapted for filterfeeding structures, the sticky structures grab organic particles from the water and take to the mouth. Their carapace has been severely stretched in a way that elevates the mouth high above the ground, far from having to compete with seafloor sifters and lurkers, at the bottom of the tube are spiky structures that attach it to the substrate. They are broadcast spawners as they cannot move to their partners, and can retract their heads inside the tube.

Basal tribaculate by AnPurple

CALIXOZOANS

Calixozoa by Agen5

Calixozoans, or "cup-shaped animals", are a basal group of trilaterians, appearing even earlier than gammaroids, their body is marked by a cup which contains a rugged inner surface which contains cells to exchange gases with the water and absorb food particles. It has at the same time a rather complex structure in its body, the outer surface of the cup has varied textures and shapes and its mostly softbodied. The animal has three stalks that hold it onto the substrate, the animal is capable of minimal motion of those stalks, and sports a simple nervous and sensory system. It completely lacks proper eyes like the rest of the grade, instead sporting several light-sensitive cells. In the face of sudden changes in lighting it will contract and hide in the substrate or landscape, returning to its resting position once safe. The general method of feeding by these creatures is siphoning water for organic particles by closing and opening its cup.
Some entire classes also partner with specific types of algae, offering shelter to them, and in exchange receiving sugar and camouflage from the algae, and thus appear red or golden.

Some calixozoans also developed toxins to deter aggressors, by Agen5

Calixozoans according to the fossil record were once abundant in the equatorial parts of the planet, inhabiting the flourishing shallow water environments - lastly, they are much probably broadcast spawners, the sheer amount of dead larval forms of these animals indicate intense broadcasting seasons where millions of tiny larvae would swim away, and if not immediately consumed by predators, they would mature and form and root their own cup somewhere.

PROMETOZOANS

Prometozoans are an early sub-phylum of Metazoa, arising between the Late Albanian and the Early Paleocambrian, or between 3750 and 3850 PMA. Prometozoans receive their name after the titan of enlightenment Prometheus - as they were among the first animals to develop complex eyes, in this case, compound eyes.
Prometozoans in general have 5 pairs of limbs - one pair which is used to feed, and a pair of compound eyes, another characteristic of those animals is a hard carapace.
The most notorious members of this phylum are Sandocarids - a pelagic animal that sifts the shallow seas for algae, and Petropods - which wander the seafloor for organic particles like roombas.


Sandocaris by ruli18life, art by M.O. Valent

Sandocarids are shallow ocean inhabitants thought to be mostly herbivorous, in the sense they feed on algae colonies, what explain they relatively large size compared to other life at the time (about 12cm), given their enormous food supply.
Sandocarids convergently evolved to use the multi-paddle undulating swim pattern that is so characteristic of most Epimetozoans*, with the plus of having a V-shaped horizontal tail, having four pairs of fin-like legs along the lateral of the body, and a pair of feeding arms on the front of the head - both the under-side of the head and the tips of the feeding arms support thin cetae, which is used to catch algae colonies that happen to grown on rocks and the seafloor.

Petropod by ruli18life, art by M.O. Valent

Petropods are a class of benthic Prometozoans, they share a reduced tail section, four limbs dedicated to locomotion among sediment, and the two very short front appendages specialized in filtering of organic detritus (marine snow), thought to have evolved parallel to Sandocarids after the fall of Albazoa.
As a whole, this group is extremely resilient, adapting to a life style similar to Earth's giant isopods, it's orders and subspecies span from the deep sea ridges in the equatorial region to the shallower tropical region north and south of the planet's equator.

EPIMETOZOANS

Ancestral bodyplan conception of a common ancestor for epimetozoans, by M.O. Valent

Epimetozoans receive this name from the titan that created the animals and their unique quirks in greek mithology. Epimetozoans are formed by 3 sub-divisions, Appendiculates (appendage bearers), Stomachunanmti (belly-swimmers), and Taivichaetophores (bristle belt bearers). Early forms of these would have appeared 30-20 million years before the Cambrian Explosion, after Prometozoans had already developed - in their early stages, Epimetozoans in general would have been bottom-feeders, finding sustenance among detritus and carcasses of much bigger and vegetarian sandocarids and petropods, at this stage they would have all descended from a worm-like ancestor.

This fusiform ancestor would have developed scales in each segment as way to move through the substrate of the late Albanian period, now there is quite an uncertainty about what exactly would have triggered such characteristics I'm going to expose here, but cosmic rays and a nearby supernova may have been the culprit here.

In those 20-ish million years, they would have split in the three divisions with vastly different lifestyles we know of today.

Taivichaetophore by Agen5, art by AnPurple

Starting with Taivichaetophores, those evolved an elongated body, using one of their five pairs of limbs as an anchor into the substrate, while the other four pairs remain above it. The animal sort of dances in the water to attract other animals but don't be fooled, these hard bristle structures on the animals head pack a deadly combination of neurotoxins, immediately numbing its prey while it secretes digestive fluids and drink it through its proboscis structure. The animals became increasingly more successful as reefs and algal communities started to pile up the shallow nutrient rich seas of the early Cambrian as the continents drifted apart, at the height of its richness many taivichaetophores resembled algal tethers due selective pressures in camouflage, and as a lot of other animals in this list, they are broadcast spawners.

Going to Appendiculates, the fossil record becomes a bit confusing, though, a layer of slightly more radioactive sediment along with a peak in deformed animals between 16-15 million years before the Cambrian indicate some sort of cosmic event took place (informally nicked the Ruli Event), possibly a supernova would've taken place by this time, thus radically changing a couple of key hox genes in the local population, it is not entirely clear whether or not the characteristic dual pair of eyes of epimetozoans in general was caused by this or reinforced in some way, at the moment this is the most acceptable explanation of why Hexalobopods have 6 pairs of limbs pentalobopods have 5 pairs of limbs, and belly-swimmers have 7 pairs, which one is original set of legs is still uncertain.

'Cleaner' Ossorinia by M.O. Valent

Starting from the bottom up, Pentalobopods are a polyphyletic group, but it has been usually used to refer to Periergostomates (peculiar mouth) in general, these are by far one of the most successful clades in Paart's natural history so far, due their sheer constantly rising diversity throughout the entirety of the Cambrian.

Periergostomates long history of success start with Euossorinids (true Ossorinias), a family or order of animals found all over the tropical belt of Paart, only two components are known from this early form of ossorinids, easily discernible by their headgear armor - we can infer that ossorinids evolved to occupy two niches at first, detritus cleaners and ambush hunters, and they would have developed around 10myr into the Cambrian.

The general characteristic of this clade as a whole is the extended appendage coverage, making a proboscis or a trunk, the mouth parts are included inside the trunk, and is simply amazing what a starting point this was for a lot of truly peculiar mouth sets. Epimetozoans have two key mouth parts, ossorinias invested their 'evolution points' in those mouth parts in order to create multipurpose tongues.

In hunter-ossorinias these tongues were stiffened to form spears to puncture and cut through prey flesh, and in cleaner ossorinias their tongues reach out to scrape organics and carcasses from the seafloor.

This group would continue to diversify slowly until the the mid Cambrian, 32myr from the zero-year - this date is particularly special because it marks the Cambrian Thermal Maximum for Paart, an age of dense, humid climate and great biological diversity in tropical zones, along with the increase in temperature for the period, there was also a great increase in ossorinid diversity, obscure clades that have been present for a long time exploded with the new reefs and favorable weather, we call this event the Ossorinid Explosion, as over 70% of this clade's biodiversity is found around the CTM and at least some 15-20myr afterwards.

Triaconis natator by AnPurple, an interesting example of the long history of this clade so far


This group is know to have developed teeth by 15myr, derived from the hard structures in each of the tongues, but this strategy just really took off with the CTM.


Blue-winged Fterokavoris by M.O. Valent


Hexalobopods on the other side, opted for less discrete approach, hexalobopodia encompasses two groups, Fterokavoridae (winged crabs) and Nantaperlaboridae (excellent swimmer) - fterokavorids are predatory animals that for a considerable part of Cambrian history deserve the title of true sea monsters, it's thick keratin armor enriched with iron would often save it from being eaten when young, and most if not all fterokavorids would bear bite scars from the times they were almost something else's dinner - sometimes, even other carnivorous Fterokavorids.

When fully grown to about 15 centimeters - Fterokavoris could in one-hit snap most of animal armors with it's crab-like claw appendage, strip their carapaces off their bodies and cut their insides in pieces small enough to fit in it's small semi-circular mouth.

Their carapaces come in all sorts of rust colors and patterns, and they move by a multi-paddle undulating swim pattern - it's last segment, like many creatures that evolved in the relatively calm oceans of the Cambrian, evolved a rudder-like structure to help swim more efficiently over long distances, switching from simple undulation to subcarangiform swimming.

It seems to be a trend that the latter the fterokavorids, the greater is the size difference between their primary and secondary pair of eyes - this can be softly explained as they are really useful when young, and this secondary pair of eyes just become redundant in it's adulthood, once it actually stops growing with the rest of the body, and just other adult fterokavorids are a real threat.

Nantaperlaborida liquovora by YellowPanda2001

Nantaperlaborides bear strong resemblance to fterokavorids, though their mouth structures are size were greately altered, at first bearing the same size range of other fterokavorids, but later being able to attain large sizes of 30 to 50cm. Why did this happen? Well, this branch of hexalobopods adapted their mouth parts for life in the open sea, while its counterpart would have patroled the reefs, these would have been suspended high in the column of water, using its pen-like structure to filter algae and organic particles from the water.

This is compatible with the fossil record from the time, the rising temperatures and new habitats flourishing towards the CTM would have allowed nantas' to grow larger with denser concentrations of algae and organic particles washed from the reefs, river deltas into the open oceans.


"Turquoise backed claw-foot", a belly-swimmer by AnPurple

Belly-swimmers are an offshoot of epimetozoans as previously mentioned, though they have not been found in reefs or in the water columns, instead, their bodyplan suggest something very unusual, adopting a benthinc lifestyle, these animals sport leg-like appendages for walking along the deep seafloor - being pretty much a parallel ecosystem feeding on the detritus snowing from the higher layers of ocean, complete with sifters and predators of all kinds. And much like ossorinids, the mouth-parts of some clades have evolved into teeth, a second instance of teeth structures coming from somewhat unrelated animals by several million years.

THE NEXT STEP

Estimated progression of Paart's tectonic drift and climate during this time period

In a timeline of about 80 million years, 20myr from the thawing of Stalika to the start of the Cambrian, 32myr to the apex of the Cambrian Thermal Maximum, and 28myr until the end-Cambrian Thermal Minimum, an Ice Age that will serve as our first filter and the leading cause of a gradual extinction event, by cooling the planet and hitting the food chain from the bottom-up. Who knows what deep secrets and unique creatures await us after this winter episode.

BUT WAIT

So far we've been highlighting the clades and their representatives only, there are several niche aliens waiting to be discovered by you! Be it by reading the deep archives once they become available, or by joining Project Paart in our Discord Server.

Stay tuned for more updates, it has been a pleasure to serve with you so far!

- M.O. Valent,17/11/2021

Last Updated, 23/11/2021

Last Updated, 30/08/2023

NEOCAMBRIAN COMING SOON!

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