The Biology, Agriculture, and Paleontology thread

That doesn't really tell you much about what the actual animal looked like, though. Look at modern whale skeletons, they look nothing like what the whale looks like.

They tell us PLENTY tho. We know they have a layer of bubbler below the skin, and toothed whales (but not baleen whales) have a melon organ in what is anatomically the upper lip to nostril area (but that looks like a forehead).

Don't underestimate what we can know from bones. Specially when dealing with the ancestral stock of a living group.

Old restoration of "archaeocetes" have historically been throughly shrinkwrapped, which is OFF when dealing with aquatic mammals, which will have bubbler or thick fur.

Yes, it's the shrinkwrapping I was referring to, which leads to bizarre results in whales, especially if you just go by the bones.

Of course, that is mostly due to the melon; baleen whales have skulls that quite match the outline of the live animal's head. I'd expect basilosaurs to have pretty much a streamlined face, without the blob of soft tissue used as a sonar. Wouldn't be surprised by whiskers still being around, either.

Still, you wouldn't be able to make out the contours of the skull bones; those are mammals, and marine mammals to boot. Mammals have VERY fleshy faces to begin with.

I don't think I'm ready for the sheer disappointment of eventually learning dinosaurs' true shapes.

Who knows, maybe they looked pretty much exactly like modern day animals. I certainly hope it doesn't turn out that they were just really big birds.

Edited by dRoy on Aug 5th 2023 at 2:42:58 AM

I mean, we do know the shapes of a lot of different dinosaurs. We even know what color some of them were.

Who knows, maybe they looked pretty much exactly like modern day animals. I certainly hope it doesn't turn out that they were just really big birds.

Yeah it turns out they were, at least the therapods. Birds are just dinosaurs but without the largest-sized ones, in fact.

But they probably did look relatively similar to modern things insofar as they probably had all kinds of jiggly skin flaps and things.

I don't see why that would be disappointing though. Modern dinosaurs do all kinds of things that are interesting, and you can go out and see them do those things now. Statistically, you could probably look outside and see at least one dinosaur if you wait.

Edited by Florien on Aug 4th 2023 at 11:25:03 AM

"All Yesterdays" is a great book about this subject, and makes some suggestions about what dinosaurs may have been like, as well as showing what future archaeologists with equal knowledge of mammals (as in, only through fossils and distant relatives) might make of modern day mammals.

This is the suggestion for cats:

Note how it follows several tropes and problems about our view on dinosaurs (like not getting the fur right, missing details like whiskers and ears, having "cool" colour schemes), while also incorporating some current corrections (adding sparse fur and lips) that still miss the mark quite a lot.

I’ve been watching Prehistoric Planet. I’m taking it with a big grain of salt - I don’t think we can know nearly as much as they’re depicting about behaviour, at least not with a reasonable degree of confidence - but it’s still entertaining, and I like the bits at the end where they explain their extrapolations. I notice they’ve made the mosasaurs fatter (more whaley) than earlier depictions did.

And did the names change since I was a kid? Some of the animals they’re calling mosasaurs are definitely ones my brain would label ichthyosaurs.

It’s hard for me to wrap my head around how the biggest dinosaurs (and biggest mosasaurs) could possibly eat enough to live. Even if the herbivores spent basically every waking moment eating, and the earth had more vegatation than now, these are creatures the size of several elephants at least, and (like elephants) they are not ruminants and so wouldn’t have the highest digestive efficiency. And for the predators…just how?

Edited by Galadriel on Aug 5th 2023 at 9:31:43 AM

Dinosaurs may have been more metabolically efficient than modern mammals, so not being ruminants wasn't a problem for them. Additionally, I've heard that making the mosasaurs that bulky may have actually been somewhat inaccurate as well, as they wouldn't have needed much blubber in the warm, shallow seas that were abundant at the time.

I think Mosasaurs are a special case of Ichthyosaur, much as Rainbow is a special case of Trout.

Not at all. Mosasaurs are ACTUAL lizards. Toxicoferan lizards, either closest to anguiforms (monitors, Gilas and slowworms) or to snakes (which ARE lizards, just a very specialiced group of legless lizard, and not every legless lizard is a snake or even close to them).

Ichthyosaurs, well, we don't really know where in the reptile tree they go. They are likely to BE true reptiles (as in, part of the lizard + tuatara + turtle + croc group, like plesiosaurs or birds are).

Mosasaurs were traditionally restored as eel-like, or even as merely lizards with a flat tail and with flipper-like limbs. However, we found body contours, skin, and did comp anathomical work, and, well, they were tunniform. They evolved into a shark-like body shape. And they did all of that after the Turonian extinction event, where both ichthyosaurs and pliosaurs went extinct, freeing up niches that the watergoing lizards readily took over.

And, well, the torpedo-shaped active marine predator is something that keeps evolving. Nowadays we have mackerel sharks (great whites and makos), billfish (whose closest relatives appear to be archerfish), tuna (part of the true mackerel family, but the closest relatives of that family are seahorses), and dolphins (which are the most conservative living whales, as Dorudon is quite dolphin-like and close to the ancestry of true whales... but cetaceans are part of the even-toed ungulates and the closest relatives hippos have).

The largest mosasaurs were the size of macropredatory cetaceans. It works, they eat other large animals. As for dinosaurs, they were warm blooded, but weren't generating as much heat as mammals, and they had INCREDIBLY efficient respiratory systems; in addition, the ones that were outright larger than any mammalian equivalent, theropods and sauropods, had plenty of pneumatization, air sacks all over the body, which were used for both respiratory efficience, and for making the body lighter to carry around. An elephant next to a sauropod is like a solid stone bridge versus a suspension bridge. As for ornithischians, like Triceratops and Edmontosaurus, they top out at weights comparable to the largest elephants or rhino relatives, which, may I add, weren't ruminants yet got larger than any ruminant ever.

Edited by Eriorguez on Aug 5th 2023 at 2:52:05 PM

Thank you for the answers! That’s extremely interesting and informative!

I thought mosasaurs got quite a bit bigger than a sperm whale.

plenty of pneumatization, air sacks all over the body

I read a fantasy series that I think used this as their mechanism for dragons.

Edited by Galadriel on Aug 5th 2023 at 9:30:16 AM

The larger estimates for the larger Mosasaurus and Tylosaurus species are still SHORTER than living male sperm whales, and sperm whales pretty much got their larger individuals culled out during the whaling age, so the average size used to be larger.

And that's just lenght; mosasaurs are not as bulky as a sperm whale (and, for the record, the 17 meter mosasaur is due to restoring it in a way nowadays doesn't seem likely):

If we compare them to both extant sperm whales and the extinct killer sperm whale:

And yeah, bird-line archosaurs used pneumatization to develop flight several (pterosaurs, and most likely several times in pennaraptorans). Makes sense, it is throughly efficient.

Edited by Eriorguez on Aug 5th 2023 at 8:33:50 PM

The lead scientific consultant on Prehistoric Planet was Darren Naish of Tetrapod Zoology, who was also one of the authors of All Yesterdays which Redmess mentioned. Both make a point that oversimplification is just another kind of speculation - all documentaries fill gaps in the fossil record, by necessity, and it's important not to fall into habitual preconceptions of what an adaptation is 'for' or what constitutes 'normal behaviour'. For example, the idea that pterosaurs were birdlike (because those are the egg-laying flyers we're familiar with) is surprisingly prevalent, but evidence indicates newborn pterosaurs could fly almost immediately and reasonable inductions of what that would allow and require led to Prehistoric Planet's depiction of their life cycle.

(All Yesterdays was revolutionary to modern paleoart. As I recall, at least one of Prehistoric Planet's segments - the dancing carnosaurs - was pulled from its pages, and I'm pretty sure Naish was personally responsible for the choice to showcase a tyrannosaur for once who is raising t-rexlings rather than messily devouring ceratopsians at all times.)

Random musing about Charles Darwin:

While I already knew Darwin researched barnacles. I didn't know, however, he spent 8 (infuriating) years on them and nearly drove himself mad in the process, saying things like "I hate a Barnacle as no man ever did before, not even a Sailor in a slow-sailing ship." Also, apparently Darwin wasn't the only contemporary biologist who was fascinated/confounded by barnacles.

Thanksfully, for both future biologists as well as his sanity, it turned out to be a incredibly worthwhile endeavor. To quote a Science History Institute's article on the subject, "provided fascinating insights into evolution," such as how certain organs in one barnacle species were often repurposed in another species, just like how the forelimbs in ancient mammals got transformed into wings in bats and flippers in dolphins.

Very interesting...!

Edited by dRoy on Aug 11th 2023 at 8:40:38 PM

Darwin studied orchids too (essay by Stephen J Gould).

I think Darwin started out as a botanist. It's his experiences that are still used to understand the mechanism of phototropism.

I didn't know that but I'm not surprised either.

I find it interesting how Darwin and Gregor Mendel, whose ideas had a lot of overlapping areas and experiences in botany, were contemporaries and yet never actually met each other.

Amusingly, Darwin did actually own a copy of Mendel's book, though it's apparently clear that he never once opened it (something like you needed to cut something to open the book and that thing was still there), and IIRC it was in a language he didn't actually know.

There's an alternative timeline for you.

Completely random but I finally found what some of the jellyish blobs that were spooking me while swimming are. It was just some comb jellies.

Still not gonna stop being careful when swimming though, you never know when swimming. >.>

At least we only mostly get fried egg jellies (Cotylorhiza tuberculata link to wikipedia here) which are harmless and honestly kinda cute. This has been your random beach patrol.

Meet Pachypanthera, the first bone-eating cat!

That tangentially reminds me of this meme:

Jellyfishes are fascinating creatures, to say the least.

Random musing.

So I'm watching a manga/anime series Made in Abyss, a work infamous for its horrific worldbuilding. And even for that series, a creature that is considered one of the most terrifying is a species of insect that lay their eggs in their victims' eye sockets as living feed for their young.

And honestly? While I was disturbed and terrified by many things in the series, THAT was the only part that merely amused me: I've seen so much worse stuff in nature documentaries.

When you hear "ovipositor" in a nature documentary, ESPECIALLY one involving wasps...there are high chances that things will get interesting, like shown in this video.