Mouths, Mandibles, and Teeth
Mouths and jaws are something I imagine to be more modularized/parametric-part based than appendages just going off the fact that the majority of mandibles and mouths are slight alterations to existing structures.
There are clear evolutionary chapters on our planet’s history regarding the use and diversity of mouths. They reveal a story on how the majority of animals got their food. I’ll go over these briefly to provide context.
STATS AND ABILITIES
These are the major abilities and stats which mouths and modifications to mouths will generally revolve around. Note that the general constraints are also at play here, but I will be focusing on the actual, mouth and mandible-specific tools.
Abilities
These are the major abilities attached to the jaw of an animal.
- Eat - Ability to engulf items. Available to all mouths; prior to the evolution of a mouth, eating works through contact of plankton clouds and substrate with skin.
- Suction - Ability to absorb material and small enough prey. Available early on to some animals without and with jaws, though effectiveness dissipates at larger masses.
- Bite - General chomp ability, inflicting damage on other animals. Available to mouths with some sort of jaw.
- Grasp - The ability to grab items and, if discrepancy in mass is big enough, prey. Requires a jaw.
Attributes
These are the major stats influenced by mandibles. For more on ingestion rates, look at this post: Metabolic Rate System - #5 by Deus
- Ingestion Rate - Essentially what component of whatever you eat is accessible or digestible by your organism. Eating plants with carnivore teeth results in only 40% of the nutrition, eating armored animals with teeth not able to break the armor results in only 20% of the nutrition,eating shrubbery with teeth designed to graze grass results in 50%, etc.
- Raw Damage - How much damage your jaw structure is able to apply. Shorter, wider jaws generally are able to create more baseline raw damage.
- “Effectiveness Coefficients” - Essentially, stats which changes damage applied to an organism depending on your jaw. Wider jaws are more effective against tougher material, while narrower jaws are more effective against flesh.
- Range - The range at which effects can be applied. Longer snouts provide greater range.
- Grasp-Related Factors - How well a mandible is at grabbing items. Generally revolves around how long you can hold an item, and the maximum size of item you can hold. Duration of grasp is more relevant to prey items, while maximum size is influential for both carnivores and animals which can interact with their environment. Narrower jaws are generally better for grasp.
MOUTH CATALOGUE
These are the general major types of “mouths” available to players.
Mouthless - Absorption of material occurs through the skin, meaning other stats, like surface area and appendages, are more important.
Jawless
Simple jawless mouth which basically enables engulfment, with no bite, no suction, and very little range.
- Suction - Boost to suction, though reduces size of engulfable matter.
- Toothed - Believe it or not, teeth-like structures likely evolved before mandibles, with conodonts especially displaying these capabilities. Allows for a very limited bite function.
Jawed
In general, jaws can be modified in a parametrized way like this:
- Length - Longer jaws decrease bite damage, but increase range. Shorter jaws increase bite damage, but decrease range.
- Width - Wider jaws increase max damage and impact on tougher skin as opposed to narrower jaws. Narrower jaws increase grasp strength and impact on less tough skin as opposed to wider jaws.
Arthropod Mandibles - Accessible relatively early on, the mandibles of arthropods will be extremely customizable, with the potential for more extensive abilities attached to them. More modification and specialization options available to arthropods in comparison to animals with an endoskeleton. Arthropod mandible raw damage doesn’t scale up with mass as strongly as high mass endoskeletal animals.
- Proboscis - A more advanced mouthpiece available later on in the Aware Stage. Takes away bite ability, but opens up interactions with unique flora, as well as parasitism. Allows access to ubiquitous food sources, such as productive plant species and parasitism, but with practically no capability for predation.
Endoskeletal Mandibles - Generally allows the highest amount of stats when specialized, though more elaborate and expensive to develop/modify than arthropod mandibles, and generally less adaptable.
- Teleost Jaw - Extendable jaw, like in the majority of extent fish today. In general, strong boost to suction, range, and grasp ability underwater in exchange for raw damage. Increased streamline measure. Incredibly useful for highly-adapted marine animals who pursue nimble prey, less efficient for larger animals which hunt larger prey or terrestrial animals, where suction is completely nullified.
- Beak - Less raw damage and no access to teeth, but strong boosts to ingestion and efficiency rates, and much less impact on mass and center of gravity. Incredibly efficient for animals that are highly specialized around a food source and for animals which prioritize mobility.
Chitinous Beak - Available to soft-bodied organisms. High damage with some suction ability, and limited grasping. Much less diversifiable than either of the other two mandible options; provides decent stats, but the stats, with perhaps a tiny bit of modification, are largely what you’re gonna get.
TEETH
Teeth will be available to animals with an endoskeleton that don’t have beaks, and will allow for further diversification or amplification of the stats of the mandible. Adaptations to chitinous beaks and arthropod mandibles can reflect the function of teeth - for example, serrations in beetle mandibles - but are alterations to the underlying mandible structure itself. True teeth allow for an additional layer of customization to a mandible beyond its shape, allowing for more diverse function.
Once players unlock teeth, a modification option opens up for the player’s jaw. Players will be able to specify the shape of teeth, as well as their distribution in the jaw. Teeth placed near the front of the mouth are more influential on stats related to interaction with the world and other animals (grasping, damage, effectiveness coefficients, etc.) while teeth placed in the back of the mouth are more influential on ingestion rate. The shape of teeth will alter the stats discussed below in different ways - conical teeth increasing grasping, thicker teeth being more effective against armored animals, shorter teeth being more efficient for plant matter, etc.
Teeth augment and manipulate these stats:
- Ingestion Rate - Influential in the diets you can eat, with flatter teeth better at grinding plant matter, and sharper teeth better at tearing meat.
- Raw Damage - Effective teeth can damage prey items well.
- Grasp-Related Factors - Certain teeth arrangements enhance grasping ability, such as conical teeth.
- Effectiveness Coefficient - Certain teeth are better at damaging certain mediums; for example, wider teeth being better at damaging armor, and skinnier teeth being better at cutting through flesh.
When a tooth type is specified, players will be able to place and drag that tooth onto the mandible. Players will have sliders that allow control on the location and frequency of teeth. In the below concept, players can increase the distribution of teeth by pulling the arrows on the end of the lines, and can move the location of the teeth by dragging the circle in the middle of the range:
Players will be able to create additional teeth types once a certain level of progression is unlocked. Similar to the multicellular editor, creating another tooth type starts as a duplication of an existing tooth. Players will then drag that tooth onto the jaw, which will replace existing underlying teeth, or populate un-toothed areas:
Additional Notes on Teeth
- Increasing the size of a tooth type visually means less of that tooth in a given region of the jaw, and decreasing the size visually means the opposite.
- An unpopulated space on your mandible can mean forgoing some stat bonuses, but can also increase the max size of whatever teeth you have in your jaw, which can also enhance stats. That opens up space for animals like Dunkleostus, who have prominent, giant bony teeth in the front of their jaw, but no such teeth in the back.
- Certain teeth can be modified to attach certain benefits; for example, being able to envenomate prey, or the ability to chop through wood. These will be more important in later portions of the stage.
Differentiated vs. Regrowable
Differentiated teeth are a unique characteristic of synapsids (proto-mammals and mammals), who have sections of their mouth uniquely catered towards different functions. Though some non-synapsid animals have differentiation in dental structure - fangs in certain fish and reptiles - the degree of differentiation is much less, and there is much less sectional specialization.
Differentiated teeth obviously allow for a lot more diversity in mandibles, but also come with a cost; in general, the more your teeth are differentiated, the more significant losing a tooth is. Animals with less differentiated teeth, like sharks, are often able to regrow lost teeth rapidly, while animals with more differentiated teeth have limited ability to replace teeth. For animals like sabretooth cats, losing one of their fangs was essentially a life-long disability.
It’s difficult to think of a way to proxy this in Thrive. An immediate idea popping into my head is that trying to bite material that your organism doesn’t have a good ingestion rates or coefficient factors for can debuff your stats derived from teeth temporarily, and this debuff can last longer the more different your teeth are. That way, it is implied that less differentiated teeth are repaired quickly, while more differentiated teeth don’t recover as fast. This concept sounds fine on paper, but it involves another mechanic, and it might be bothersome or too much detail for the type of detail we’re focused on.
Another idea I have is that the more differentiated your teeth are, the more severe the disparity in ingestion rates and effectiveness coefficients are. So for animals with undifferentiated teeth, you might be able to get atleast some nutritional value from items that fall under your digestive system’s diet even if you don’t have well adapted teeth for that purpose, and can more generally inflict damage on more types of armor and flesh than animals with specialized teeth. On the other hand, for animals with differentiated teeth: if your teeth aren’t suited for it, then you get basically nothing from it. This fits in well with the stats I brought up, but it might have a weird effect on balancing; with this system, would animals which first evolve teeth be the most versatile, and animals which have more evolved teeth be less versatile?
So that’s one area I’m not super certain on. I am more inclined to second idea just because it fits neatly, but I think this is something we’ll have more answers for as we get a clearer understanding of the macroscopic stage.
Concluding Thoughts
I think the above concepts are pretty straight-forward and concise. Jaws, teeth, and all that sort of stuff related to the mouth are one of the more obvious “form = function” trends we see in nature, and there’s a good amount of comparative anatomy research surrounding jaws.
The more confusing part with jaws revolves around progression. As I mentioned, adaptations in jaws are the result of adaptations even more incremental in nature than adaptations to appendages and limbs. With appendages, there’s a lot more of a “place and tweak” application there. By that I mean in arthropods, limbs are pretty frequently added and removed; and even in vertebrates, who do regularly stick with the two or four limb body plan, segments on the limb are added and removed somewhat frequently. So providing the player with more significant tools related to limbs is pretty intuitive.
With mandibles, the mandible is much less frequently messed around with; once a mouth is placed, alterations are frequently very slight. So the tools we provide to the player will also likely have to be slight as well, and progression through different “variants” of jaw - for example, going from a mouth opening to a jaw, then from a jaw to a beak - is pretty binding. We’ve seen the progression and reversion of a limb into a foot and back into a fin much, much more frequently than we’ve seen the progression and reversion of a mouth from a mandibulated, advanced jaw to a simple opening, or a beak back into a normal, toothed, jaw, etc.
Writing this out and thinking about this more, I realize that this isn’t really something that requires super-specific handling, or hard locks, or anything like that. If we set it up so that jaws are really beneficial, and make it so that jaws are pretty influential, players and auto-evo will naturally treat them as significant pieces of anatomy and reside in small tweaks.
I think I’m just trying to say that, even though we are arguing for a more part-driven, parametrized system, we cannot think of it as just placing and dropping another part to increase a jaw like in Spore. Variations in appendages, jaws, and limbs have to revolve around altering existing structures in a way that unlocks a different variation. For example, instead of going into a “Variant” menu like we have with organelles right now, turning your beak into a jaw will have to involve the player losing teeth, then turning the segment of jaw without teeth into a keratinized bony structure, with different bonuses applied.