Blood and Bones and Feathers II

Xenobiology thoughts.

• Did you know that manatees don't have eyelids? Nope. Their eyeball sits in a sphincter, and they push it out (to open the eye) or in (to close it) by the same mechanism that lets you swallow and vomit (to use the least disgusting example I could think of). Not saying your aliens have to do something that weird—I mean, sharks have eyelids like ours—but just...don't take "eyelids" for granted. (Interestingly, I think octopuses do something similar to what manatees do, sticking their eyes out or drawing them back in to protect them.)
  
  Also, manatees should be called "sea elephants", not "sea cows". They are Afrotheria, related to elephants and hyraxes but not to any of the other clades of plant-eating mammals (such as the Ungulates or rabbits) or aquatic mammals (such as the Pinnipeds or Cetaceans)—all of those three (yes, three, Cetaceans are Ungulates, Pinnipeds are Carnivora, rabbits are rabbits) are Laurasian.
• That fact, incidentally, that Afrotheria are a whole different lineage from Laurasian animals, is fascinating. Actually apparently there are three, aside from Afrotheria—Euarchontoglires or Supraprimates, which as the second name suggests includes primates, but is also rodents, lagomorphs, tree-shrews, and colugos; Xenarthra ("weird joints") which is only the tree-sloths, armadillos, and anteaters; and the Laurasiatheria, which is shrews, hedgehogs, bats, ungulates, and carnivorans (and pangolins, which are not related to Afrotherian aardvarks or Xenarthran anteaters). It's interesting to me in part because we might be looking at a division in the mammals that's as fundamental as the Saurischia-Ornithschia split in the dinosaurs—assuming that that split is fundamental. (Given that "Ornithschia" means "bird-hipped", and yet birds are Saurischian, "lizard-hipped", dinosaurs, "ornithschia" and "saurischia" might well be polyphyletic groupings. And since we mostly only work these things out with DNA testing, we'll never know now.)
  
  It's also interesting just in general, that, for instance, elephants are so weird partly because our last common ancestor with them was some time in the Cretaceous—because Africa was an island, like modern Australia, from the breakup of (West) Gondwanaland until the Neogene, i.e. from 110 million years ago to about 23 million. Every hoofed mammal in Africa—which includes not only antelopes, giraffes, wild asses, zebras, and camels, but also hippos and rhinos—only dates to the Neogene. Same, I think, for the African carnivorans and primates—Africa before the Neogene had elephants (albeit the first ones were the size of large housecats), but no antelope, lions (and the felidae somewhat predate the Neogene), or monkeys. On the flipside, the rest of the world didn't have mammoths or mastodons until the Neogene, either—specifically the late Miocene or early Pliocene, probably a bit after 6 million years ago. I bring this up here because it's cool, but also because you should probably block out the cladistics of your aliens and their ecosystem.
• All those "six sexed species" science fiction stories fall afoul of another principle, besides the "how does that work for every other species in their biosphere?" and "wouldn't that be more efficiently handled by something like a termite-colony's caste system?" ones that I raised.
  
  Do you remember Kes in Star Trek: Voyager? And how her species gives birth only once in their lives...to one offspring? Which means (your novella's handwave isn't canon, Trekkies) that every generation of her species is half the size of the one before it. A six-sexed species fails basic math just as hard. There is a reason that a "replacement" birthrate, for humans, under optimal conditions, is "slightly over two children per reproductive unit". On average, you're gonna get roughly half male and half female; the "slightly over" is wiggle-room for accidents. So having one kid of each sex, with the occasional extras-per-litter, get to reproductive age, means you have enough breeding pairs to keep the numbers up.
  
  If your breeding-system requires six individuals, then you require six children per reproductive unit. Every family has to have six children survive to breeding age, plus a bit of change to account for unforeseen deaths, just to keep the numbers steady. That means that, right out of the gate, as an intrinsic part of reproduction as such, every single species on your planet finds surviving, as a species, three times as hard as life on Earth.
• I've recently inclined to the position (I haven't mentioned them much in the books, and never in any detail) that the non-"mammal" fliers on the zled homeworld (Lhãsai) are something like Sharovipteryx, except able to flap their hindleg-wings. Maybe the wing-membranes are more like bat-wings, with membrane stretched between fingers? Or toes, rather. And they could knuckle-walk on their hindlegs when not flying—which can give you some speed, watch the dragons in Skyrim do it sometime. Only one genus on Earth ever went with Sharovipteryx's strategy, but that means it can be done. (That's also one more genus—which is to say an infinity—more than ever had a six-sex reproductive system.)
• In Korea, they put a type of hagfish (it's like a lamprey) into a bucket, and then tap the bucket with a stick, agitating the fish. Hagfish secrete mucous slime when they're frightened, I'm not sure if it makes them harder to find or slipperier or what. Well, the Koreans agitate the hagfish until it's filled the whole bucket it's in with slime...then they fish the slime out and cook it like egg-white. Mm-boy.
  
  While no earthly consideration could persuade me to try any dish containing hagfish slime, it is an example of the unsuspected possibilities in an ecosystem. And "what your aliens eat" is an important world-building concern.
  
  Here's a less disgusting example. Have you ever actually seen an agave? Or more to the point, touched one? The term "agave nectar" probably makes you think of something like an aloe (apparently some crazy people use "American aloe" to refer to the centuryplant, a type of agave they don't make pulque from), but no, agaves are tough, woody plants, probably less "succulent" than prickly-pear or even saguaro; the edges of each leaf are hard and shriveled and stringy, since the edges form the spikes. It's the core of the plant, once the leaves are chopped off, that you get the "nectar" (really sap) from. If someone pointed to an agave just growing there, and told you that you could make liquor from it, you'd think he was nuts.
• You know Protista, the taxonomic kingdom? Well, no, you don't, because apparently, that kingdom doesn't exist. Apparently now the term means "a polyphyletic catch-all term for any eukaryote that's not a plant, animal, or fungus". It's considered doubtful whether the, what, three? kinds of algae, are all the same thing, let alone whether any algae are the same as dinoflagellates, euglenoids, amoebae, apicomplexa, or trypanosomatids (that last one causes African sleeping-sickness, which is in the top ten most horrifying diseases on that continent—and consider some of its competition).
  
  And then, a whole bunch of what we thought were bacteria are actually "Archaea", which are the weirdest little suckers you will ever see. Not only do they do things like live in volcanic vents (and your belly-button), but they have weird cell-membranes and some of them "eat" not only things like sugars but also things as bizarre as ammonia, metal ions, and gaseous hydrogen. Some of them photosynthesize, some of them fix nitrogen; apparently none do both (which is one of their differences from bacteria, cyanobacteria being one of the main nitrogen-fixers and taking their name from their blue-green chlorophyll).
  
  Much as I call Lhãsai's small, be-exoskeletoned creepy-crawlies "bugs", I imagine that the term for their microscopic life would be "germs" (maybe "microbes"). They probably have multiple kinds (probably an organelle/organelle-less division, like what separates eukaryotes from prokaryotes), but since the last common ancestor of their life with ours was the gas the Milky Way formed from, none of our technical terms are appropriate. And no, Cargo Cultists, "bug" isn't a technical term.
• It occurs to me, I need to add an explanation to something. I've mentioned that zledo taboo scavenging, and thus "scaveng·er/ing" is a cussword in their language (although, arguably, "scavenging at graves" is actually just the cannibalism taboo, not a double—you'll see why in a second). The thing I need to clarify—justifying this point's inclusion here—is, "What's scavenging?", for a species where most members don't kill their own food, but buy food killed by others? Its base meaning is "eating meat you find", of course, but it's obviously not scavenging if you "find" it in your fridge, purchased from a hunter.
  
  The answer is, "scavenging (as a taboo) is eating something killed by an animal other than man". Or otherwise eating meat you find lying around—they could probably eat an animal they road-killed, but not roadkill scraped off the road. It's somewhat similar to the Jewish concept of "treif" (literally "ripped", as by wild animals—like the Mothers of Invention album), although they apply that word to all non-kosher food (which may or may not imply that people who eat it are animals; it's probably just a convenient shorthand whose potentially impolite implications were not noticed). Navajos and most other Native Americans actually have the same taboo, probably because you can catch some fascinating diseases eating things coyotes have been chawing on.
  
  Thus, "scavenging at graves" is a zled cussword that's only concerned with the cannibalism taboo, since the issue is eating people, not how you got the opportunity to eat them. They still call it "scavenging", though, because its base meaning ("eating found meat") would usually apply, and it also has a dysphemistic sound. ("Scavenge at the graves of the people you murdered just so you could commit necrophilia", a zled "cluster F-bomb" a character employed in a scene I wrote recently, just works better than "eat the corpses of the people etc.")
• Sauropods had really weird forefeet. They weren't that much like elephants' hands; for one thing, they don't appear to have had a pad like an elephant. There wouldn't be room. The metacarpals were bundled together into a more-or-less circular column (sauropods had horseshoe-shaped footprints), and generally, the only digit you could actually see (and the only one with a nail) would be the thumb—and that was only visible by its nail. The Titanosaurs didn't even have that—nor any phalanges, as far as we can tell they walked directly on their metacarpals (it's not that weird, chimps and gorillas walk on their metacarpals, albeit by folding their phalanges out of the way).
  
  The sauropod hindfoot seems to have been more normal, although, despite seemingly having five digits, they only seem to have had three nails, which might mean two of them weren't visible outside the flesh. Also? They walked plantigrade in back, like bears, rather than semi-digitigrade like elephants. That's apparently a fairly new idea, the plantigrade part, but apparently it makes the angles of their necks and tails much more natural (and the new angles, apparently, showed them to have massive neck-muscles). Another thing we're recently discovering about sauropods is they had spikes, some of them long and scary, on their backs and necks (and on the whips of diplodocid tails); rather than being all smooth like in Land Before Time they're actually more like iguanas.
• It occurs to me that, the Lhãsai flier that's in their "reptile" class, might have α-helix keratins instead of β-sheet ones, i.e. switch the "mammal" and "reptile" associations for their biosphere. That would mean they probably have a skin more like a dolphin or pig than a lizard. I'm also thinking maybe they wouldn't be hairless? Maybe their covering will actually be chitinous chaetae—I know, that tends to imply an invertebrate on earth, but one, lots of fish apparently have chitin, and two, aliens.
  
  I think I've mentioned that the Lhãsai fliers that are in the same class as zledo have heads like sea-lions? Or maybe like otters or beavers—they're aerodynamic, and those are streamlined for water. I think I'll have them be polyphyletic instead of having a common ancestor, as beavers and otters' last common ancestor is the Boreoeutheria. Not sure how the transition from aerodynamic fur, stuck together like waterproofed fur, to full-on flight-quills occurs; probably it doesn't look quite like the transition from contour to flight feathers, but is definitely similar.