#Eutherian

[despazito]

Love it when a new character comes to you in a vision

[bunjywunjy]

Hey so what’s with so many people insisting that marsupials are not mammals? Like they’re not placental mammals but they are still very much mammalian. I’ve encountered several people trying to argue that marsupials are just marsupials and not mammals.

Marsupials are mammals, guys. They have mammarian glands which produce milk to feed their young. They are mammals. Why is that so confusing? What class would they belong to if not mammal?

WHO is saying this?? do they think that platypuses and echidnas aren't mammals either??

mammals come in three basic flavors- monotremes, marsupials, and placental/eutherian mammals. all of these animals are full-on mammals, just moving from more basal to more "modern" types.

they can be further split into two groups, prototherian and therian! prototherian includes the monotremes and some groups that have long been extinct, while therian mammals encompass both the marsupials and placentals/eutherians.

mammals are an ancient lineage that share roots with the reptile group, it makes sense that there are multiple different lineages still around! I'm glad to be sharing a planet with those weirdos today.

[markscherz]

Do frogs have baculae, or is that just a mammal thing?

With very few exceptions, frog's don't even have intromittent organs, so no, definitely no baculae there. Baculae are 100% a eutherian thing. But also, having the intromittent organ being the same structure as urine passes along is a very weird mammal thing as well. In most other tetrapods, excretion of urea is entirely separate from reproduction functions, and there are dedicated structures for use during copulation, if it involves intromission. And in fact, in basically all other groups, the sperm flows along a groove, or sulcus, rather than down a tube.

[src]

[typhlonectes]

Skull of a new periptychid mammal from the lower Paleocene Denver Formation of Colorado (Corral Bluffs, El Paso County)

Lucas N. Weaver, Jordan W. Crowell, Stephen G. B. Chester & Tyler R. Lyson

Abstract

The Periptychidae, an extinct group of archaic ungulates (‘condylarths’), were the most speciose eutherian mammals in the earliest Paleocene of North America, epitomizing mammalian ascendency after the Cretaceous–Paleogene (K–Pg) mass extinction. Although periptychids are mostly known from fragmentary gnathic remains, the Corral Bluffs area within the Denver Basin, Colorado, has yielded numerous exceptionally well-preserved mammalian fossils, including periptychids, from the earliest Paleocene. Here we describe a partial cranium and articulated dentaries plus an additional unassociated dentary fragment of a small-bodied (~273–455 g) periptychid from ca. 610 thousand years after the K–Pg mass extinction (Puercan 2 North American Land Mammal ‘age’) at Corral Bluffs. Based on these new fossils we erect Militocodon lydae gen. et sp. nov. The dentition of M. lydae exhibits synapomorphies that diagnose the Conacodontinae, but it is plesiomorphic relative to Oxyacodon, resembling putatively basal periptychids like Mimatuta and Maiorana in several dental traits. As such, we interpret M. lydae as a basal conacodontine. Its skull anatomy does not reveal clear periptychid synapomorphies and instead resembles that of arctocyonids and other primitive eutherians. M. lydae falls along a dental morphocline from basal periptychids to derived conacodontines, which we hypothesize reflects a progressive, novel modification of the hypocone to enhance orthal shearing and crushing rather than grinding mastication. The discovery and thorough descriptions and comparisons of the partial M. lydae skull represent an important step toward unraveling the complex evolutionary history of periptychid mammals.

Read the paper here:

Skull of a new periptychid mammal from the lower Paleocene Denver Formation of Colorado (Corral Bluffs, El Paso County) | Journal of Mammalian Evolution (springer.com)

[scavengerflight]

(This is 100% a ramble/shower thought type beat, so don't take me too seriously lmao)

As a conservation biology student, I've taken classes about taxonomy and how we classify living things. When we got to mammals, it got me thinking about the word "therian."

In biology, "Theria" refers to Metatherians and Eutherians (marsupials/pouch mammals and placental mammals, respectively). With this new lense on the word, it sometimes confuses me how it's used in the alterhumanity space.

If we combine the biology and alterhumanity contexts, "therian" should mean someone who identifies as a marsupial or a placental mammal, so someone identifying as a platypus (or a prototherian/monotreme) wouldn't be a therian.

For me, this makes me like words like "avianthrope" or "arthrothrope" (coined by @tomcatdiaries ) since they follow modern taxonomical systems.

Just me and my silly biology brain :> 🦴🪶

[is-this-plural]

Ahemmm.

Today we have found something odd.

About ducks.

https://www.ox.ac.uk/news/2016-11-18-ducklings-maintain-two-separate-memory-banks-visual-information

Shall we take your opinion after you read it? :)

Are all of the ducks plural?

Fuck it. All ducks, and likely most non-eutherian animals, are secretly Pacific Rim mechs. Who even cares anymore.

Rating: Plural!

[gynandromorph]

i needed to look into how to refer to placental mammals because i didn't want to use "placental" twice back-to-back; they are called eutherians. it is a very strange word that looks out of place, as it isn't common vocabulary, yet i feel deeply that marsupials would probably know how to refer to placental mammals in the same way that i could say "i pity marsupials" and most of the population would understand the sentence

[harpagornis]

On Patagomaia

So recently the largest Mesozoic mammal yet has been found. Weighting around 14 kg (just barely larger than Repenomamus giganticus), Patagomaia chainko was a terminal Cretaceous (Maastrichtian) animal that co-existed with a variety of other early mammals such as Orretherium and Patagorhynchus.

Unlike these forms, though, Patagomaia was therian mammal, which is pretty interesting since previous studies concluded that therian mammals were constrained in size by "archaic" mammals until the Paleocene. As the paper notes, the existence of a therian mammal in the Cretaceous of South America further supports a Gondwannan origin for at least some therian lineages, including perhaps placentals such afrotheres and xenarthrans. This is the polar opposite of the view that therian and in particular placental evolution started in the northern continents; indeed, eutherians are actually the minority in Late Cretaceous North American mammal faunas.

Another point added is that, alongside the malagasy gondwanatheres and the South American mesungulatids, Patagomaia demonstrates that Gondwannan mammals were on average larger sized than northern species, at least in the Late Cretaceous. This could hint at interesting turnovers in the ecology of the southern landmasses, with the local dinosaurian fauna offering little resistance to larger sized mammals.

Overall, an amazing find for 2024.

[xirayn]

As a fellow nature documentary kid, I would love to hear more about your take on Omegaverse. Anything world-buildy with it

I have put way too much thought into this because I am a chronic world-builder, so there is a lot. It ranges from the biology and evolutionary reasons behind it, to how and why social constructs came to be.

[Character examples will be in context of Stranger Things because that is my current fandom]

Now to go into it under the cut.

Note: Male and female will be used to refer to assigned sex. Trans people exist in my omegaverse with the distinction between male/female vs man/woman being culturally better understood due to the existence of subsexes.

Evolutionary Origin

Subsexes are the result of a vestigial monotreme system that developed parallel to the eutherian system that humans possess. It was socially advantageous, but biologically detrimental, which is why parts of it were kept. As a result, male omegas are unable to get pregnant despite having an estrus cycle and being capable of lactating.

Subsexes

Alphas (Hopper, Steve, Mike, Lucas, Billy, Argyle, Chrissy)

The heart of the pack, alphas are usually extroverts who keep order and generally ensure all pack members are safe and supported.

Mostly male since female alphas have been historically unable to survive childbirth due to their pseudo-penis, which also makes vaginal sex tricky.

Social constructs resulted in the ideology that alphas are the ruler of a pack and should want to be dominant in their relationships.

Alphas go through annual ruts, a period of two to three weeks marked by a heightened sex drive and a decreased ability to regulate emotion.

A roar, also known as an alpha voice, is a loud, guttural vocalization. Despite popular belief, it does not force an omega to submit or obey, but does have a tendency to activate a fear response.

Happy, friendly, or comforting vocalizations include chuffs and rumbles.

Betas (Robin, Dustin, El*, Kali*, Jason)

The lifeblood of the pack, betas tend to be supporters and problem solvers who keep everything running.

Betas will often form a partnership with an alpha or, rarely, an omega. The bond is usually platonic, though it can be romantic.

An alpha or omega child may mature into a beta. They retain the personality traits associated with their original secondary sex, but do not produce any of the hormones involved in mating cycles and bonds.

Betas have an underdeveloped vomeronasal organ, which makes them less aware of pheromones and other chemical communications.

*On rare occasion, a beta is the result of subsex sterilization. These betas are even less capable of picking up scent queues, to the point they are unable to reliably identify subsexes.

Omegas (Joyce, Nancy, Jonathan, Will, Eddie, Max, Murray)

The will of the pack, omegas are independent risk-takers who drive innovation and exploration.

Omegas are typically the first to leave their familial pack, sometimes with 1-3 other omegas to form a coalition. These groups are often the start of a pack.

Mostly female due to male omegas rarely passing on their genetics due to having a lower sperm count than male alphas and betas.

To promote loyalty to a ruler over pack and prevent rebellions, many cultures have developed the false idea that omegas are meant to be subservient.

Starting between the age of fifteen and eighteen, omegas start experiencing heats every 6-15 months. During the two to seven days a heat lasts, the omega produces sex pheromones and experience a higher libido. While omegas in heat and preheat are more affectionate and outgoing toward other subsexes, they may act aggressive toward perceived competition.

Omegas are the only subsex capable of purring.

Mates/Pairbonds

A pairbond is created when an alpha knots an omega in heat, triggering the production of primer pheromones, then bites one of the omega's scent glands, typically on the neck or shoulder. The pheromones from both partners, transferred through sebum and saliva, alter the other's hormone production to create the pairbond.

Pairbonds are renewed each heat. Two to three heats are enough to break the bond, though the addictive qualities of a pairbond can make this difficult to achieve.

Mating marks are the darkened patch of skin, resembling a bite mark, that occurs after a pairbond is formed. They fade when a pairbond is broken, but never fully disappear.

Feel free to send me asks or prompts on this.

[robbie-roo]

I have my final exam in mammalogy tomorrow morning quick ask me a question about any of these eutherian groups

[bluetapes]

Part 6 of a series interrogating the track titles for Kaijupop, the debut album of my Soft-Bodied Humans project.

The album is available on LP and digital from Gang of Ducks.

Track 6: Bat People

--

The Bat People (人間コウモリ Ningen kōmori, lit. Human Bat) are eutherian humanoid kaiju created by Toho that first appeared in the 1969 Toho film, Latitude Zero.

--

I was first introduced to the expansive sonic universe of Angel Marcloid via Fire-Toolz’ 2018 classic Skinless X-1.

I was stunned that a small label like Hausu Mountain could apparently find the resources to hire a pro-level producer, as the album SOUNDED like it had been cooked up in a million-dollar recording studio somewhere.

I was also stunned to find that not only all of the production work was done by the artist themselves, but that Angel’s own mixing and mastering services were available at very reasonable cost, an offer I immediately took up when I started my Cut A Lonely Figure and Soft-Bodied Humans music projects.

Angel wove her magic on the kaiju releases and, as I was approaching all of my favourite vocalists regarding contributing to the project, it was completely logical that I would offer her a track to vocal, and I was ecstatic when she agreed.

I explained that the music was constructed out of samples from old kaiju films and that there was ‘very loose’ theme about monsters that could be interpreted as literally or abstractly as you liked, and Angel was like ‘what if the monsters are like my personal demons?!’ and I was like yes 100% make it so.

Angel’s track on Kaijupop, Bat People, adds something searingly emotional to the project that it really needed. Musically, too, it is typically untypical – Angel unloads a shapeshifting, FX-treated, industrial howl of naked feeling over one of the project’s more atmospheric tracks.

Bat People sits perfectly between the abstract, expressive textures of Anna Homler’s Battra and the thudding, menacing shades of extreme metal in Abysmal Growl of Despair’s Minos, in one of the album’s most exciting sequences.

A beautiful, exhilarating exorcism of bad energy.

[panwithaplan]

eutherians are are eevees

[ainews]

Chargers, also known as batteries, are an essential part of our daily lives. From powering our smartphones and laptops to running our cars, batteries play a vital role in keeping our modern society functional. But have you ever wondered why chargers are considered Eutherian for sewers?

To understand this, we first need to understand what Eutherian means. Eutheria is a subclass of mammals that are characterized by the presence of a placenta and advanced development of their offspring before birth. This means that the babies of Eutherian mammals, including humans, are nourished inside the mother's womb until they reach an advanced stage of development and are ready to be born.

So, how does this relate to chargers and sewers? Well, the answer lies in the production and disposal of these essential devices. Batteries are mainly made up of heavy metals like lead, cadmium, and nickel. These metals are extracted from the ground and processed in industrial factories, often with toxic chemicals that can harm the environment.

In the past, these batteries were simply disposed of in landfills, where they would eventually leak and contaminate the surrounding soil and water. This caused significant harm to the ecosystems, making it difficult for plants and animals to thrive.

But with the rise of Eutherian mammals, such as humans, we have become more aware of our impact on the environment. We have developed more advanced technologies to safely dispose of batteries and minimize their harmful effects. Sewers, which act as a network of underground tunnels for waste disposal, play a crucial role in this process.

Sewers have advanced filtration systems that can remove harmful substances from the wastewater before it is released into the environment. Batteries, along with other hazardous materials, are directed to specialized facilities where they can be properly recycled and disposed of.

Moreover, the development of Eutherian mammals has also led to the invention of rechargeable batteries. These batteries can be used multiple times, reducing the need for constant production and disposal. This not only reduces the burden on the environment but also makes chargers more sustainable.

In conclusion, chargers, or batteries, are considered Eutherian for sewers because their production and disposal have a significant impact on the environment. The advanced development of Eutherian mammals, like humans, has led to the development of better technologies for safely disposing of batteries and reducing their harmful effects. As we continue to evolve and improve our ways of living, it is crucial to consider the impact it has on the environment and strive towards more sustainable practices.

[sookietime]

Emela-Ntouka

[tigirl-and-co]

asfggfdsdfg meet grandpa Jeremiah

[demon-birate]

*tries to explain to my mom that in terms of How Mammals Work all humans are technically born premature bc human bodies are not designed to carry a pregnancy to full term*