YMMV / Alien Biospheres

• Awesome Art: Starting with Episode 6, Biblaridion starts including fan art from other users, many of which look great. It gets taken up to eleven when Episode 9 introduces animations. Burpopo's 3D animations that are first introduced in Episode 11 almost look like something out of a nature documentary.
• Fan Nickname: "Jumpscare squids" for the elastospondyls, and "spider-monkeys" for the tanybrachids. In fact, many of the creatures in the series find themselves with nicknames in the comments section.
• Fridge Brilliance:
  • Despite many fans' guesses that the ape-like tanybrachids would become the next intelligent life like apes, they died out during the mass extinction. Unlike Earth's apes, which evolved after a mass extinction and thus had time to evolve sapience, the tanybrachids evolved before one, which wiped out their rainforests and drove them into extinction before they could achieve sapience.
  • Their extinction also makes sense from a morphological standpoint - apes had already been evolving traits that would aid them in ground life because they were advantageous for living in the trees. Those traits (namely bipedalism) would be useless for the tanybrachids, who can't support their bodies on their legs to begin with.
• Growing the Beard: While the series was well-liked from the start, it's generally agreed that it truly found itself and became even more engaging when the organisms invade land in Episode 4 and start to diversify into different niches in the episode immediately after it.
• He's Just Hiding: Overlapping with Fanon Discontinuity and Misaimed Fandom, but despite Biblaridion plainly and clearly saying in Episode 14 that the tanybrachids went extinct due to being overspecialized for an arboreal lifestyle, some fans ignore this and insist that at least one member of the tanybrachid lineage managed to make it through the mass extinction (regardless of the extinction debt they may face) and will evolve into an intelligent form much like how humans evolved from simian primates. This is an idea that Bib has mentioned being strongly against, given that a purpose of the series is to show how life on another planet can differ from that on Earth.
• Hilarious in Hindsight: In discussion, it was noted by some that the Deinognathans, with their somewhat bear-like builds, would've been better able to adapt to the open plains if they adapted a hunting style similar to the big Short-Faced Bears. They eventually wound up developing two key traits of said bears through the Malleognathans, that being their bone-crushing jaws and intimidation kleptoparasitism.
• I Knew It!:
  • It was commonly assumed by fans that the elastospondyls would be the first to develop flight due to being arboreal jumping organisms that would need to develop some sort of gliding ability in order to protect them from falls. Sure enough, that is exactly what happens in Episode 6.
  • The deinognathans were unable to adapt to the spreading grasslands in Episode 6, as a result of their fused limb girdle preventing them from chasing after prey and the lack of trees preventing them from doing their usual ambush hunting, so it was theorized they would be forced to evolve into aquatic niches, which was exactly what happened in the next episode.
  • Some fans predicted that some of the odontognathans would survive the mass extinction, due to being the Fantastic Fauna Counterpart of Earth's crocodiles, which survived the K-T extinction. The hybognathans were not only the only odontognathans that survived, but the last remaining synischians after the mass extinction.
• Memetic Mutation:
  • "And so it will [x], and die."^explanation The beginning of Episode 4 describes ways an aquatic organism will die if it comes onto land, including collapsing, dehydrating, and starving. This became an in-joke among fans.
  • SPIDERS SAY TRANS RIGHTS.^explanation Episode 10 went into more detail about the osteopods' sequential hermaphroditism first mentioned in Episode 5, resulting in many of the commenters during the episode's premiere chat joking about the creatures being transgender.
• Nightmare Fuel:
  • The osteopods can be quite terrifying if you're arachnophobic, as they resemble giant spiders with Scary Teeth in their Monstrous Mandibles.
  • Episode 13 features the deinoglossids, parasitoid kentrodonts that inject their victims with eggs via a sharp pointed ovipositor from their mouths. Imagine a tentacled snake that reproduces like a xenomorph and you'll get an idea. Even worse is that we get multiple gory and greatly-detailed illustrations of deinoglossid larvae violently bursting out of the bodies of their scandopod hosts. Worse still? The deinoglossids are one of the clades that survived the mass extinction.
• Not His Sled: Many viewers assumed that due to the tanybrachids' resemblance to monkeys/apes, they would be the ones to evolve into sapient lifeforms just like how apes evolved into humans in real life. The tanybrachids were one of the casualties of the mass extinction, jossing this theory. Biblaridion himself stated that he was happy to kill off the tanybrachids along with the fans' intelligence theory.
• Squick:
  • The tentaclostomes eat, secrete waste, and reproduce out of the same hole.^note This is later avoided with the diplostomes, a clade of tentaclostomes that develop a U-shaped through-gut to prevent their waste from mixing with their digested food. Lampshaded by Biblaridion.
    Yeah, nature can be gross sometimes.
  • The last segment of Episode 10 deals with parasites, including a lineage of tapeworm-like malacoform that lives inside osteopod digestive tracts. It's just as unpleasant as it sounds.
• Tear Jerker: The entire first third of Episode 14, which features many of the clades the audience has grown attached to over the past few years slowly dying out one by one thanks to an apocalyptic mass extinction event.
• They Wasted a Perfectly Good Character: In Episode 11, it's mentioned that after the eriotheres crossed the sea ice to Isla Crescentia, they underwent their own share of adaptive radiation much like the notoformes and xenodonts before them. However, these new forms are never elaborated on, and it cuts to the next segment immediately after this mention is made.
• Unfortunate Character Design: Like the other osteopods, the titanopods have vestigial back legs that are kept folded up beneath their body, only used for reproductive purposes. Some viewers have noted that when viewed from the back, it surprisingly resembles human buttcheeks.
• Ugly Cute: Many of the lophostomes and osteopods are surprisingly appealing despite their beady eyes and toothy mandibles.

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