#prehistoric beasts

[spacenoirdetective]

Manuel Sanjulian aka Manuel Pérez Clemente, "In the Mouth of the Beast"

[nelliesbook]

Look at these two little guys!

American Museum Journal (the publication of the Museum of Natural History), 1916

[savage-kult-of-gorthaur]

THE LARGEST BIPEDAL LAND PREDATOR-MAMMAL THE WORLD HAS EVER SEEN?

PIC INFO: Spotlight on the largest bear to ever exist standing 12 feet tall and weighting up to 2,110 lbs. Arctodus simus, the Giant Short-Faced Bear -- Arctodus simus was a very large Ice Age bear found throughout North America. This was the largest mammalian land carnivore ever to live in North America, reaching heights of up to 12 feet when standing upright. Faster and larger than any bear today, it ultimately went extinct some 12,500 years ago.

MINI-OVERVIEW: "The giant short-faced bear, Arctodus simus, was a massive Ice Age bear that was the largest land-dwelling carnivore in North America: 

Height: When standing on all fours, Arctodus simus was 3.3–5.5 ft (1–1.67 m) tall at the shoulder. When standing on its hind legs, it was 8–11 ft (2.4–3.4 m) tall. 

Weight: The average weight of Arctodus simus was 1,378 lb (625 kg), with the maximum recorded at 2,110 lb (957 kg). 

Speed: Arctodus simus was likely the fastest running bear to ever live, possibly able to run over 40 miles per hour. 

Bite force: Arctodus simus likely had a bite force of over 3,000 PSI. 

Source: https://x.com/Trad_West_Art/status/1616782158382743552.

[chernobog13]

A Xenozoic Tales stampede, by Mark Schultz.

[topshelf2112-blog]

For today’s TBR pile - Hard sciences: paleontology and prehistoric life. My first career wish was dinosaurs. I spent an afternoon once, according to family legend, being carried around by a bank president (my dad’s boss) teaching him how to say dino names right for his little boy ;)

[elodieunderglass]

itsallblogtome

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goodnightmoonvale: thecuckoohaslanded: ...

@elodieunderglass is it true the animals were so much larger in prehistoric periods because the air was much more oxygen rich?

That’s such a good question! It would be true in the case of arthropods - the group of animals with exoskeletons, that contains insects, spiders and crustaceans. Terrestrial arthropods - that is, ones that live on land - breathe air through holes in their exoskeletons.

When vertebrates (mammals, reptiles, fish, birds) breathe, we suck in air or water through noses, mouths or gills, using our muscles to suck with. We suck the useful oxygen into our lungs or over the gills, transferring the oxygen to our blood, and exhale the wastewater/gases. For vertebrates, breathing is a very ACTIVE thing. We go around actively gulping down oxygen, powered by our muscles, like vacuum cleaners. Then we fling the oxygen into the deepest, darkest, frilliest parts of our bodies by packing it into vacuum tubes (blood vessels) and powering it into every possible corner of flesh with the aid of a massive engine (heart). Mammoths and sunfish and blue whales and tyrannosaurs and dogs and us have all kinds of dark, meaty depths. We can power the air into our dark meaty depths and ALL of our nooks and crannies. Vertebrates have the infrastructure to get BIG. We’re like a city full of subways and complicated train routes.

Arthropods are more passive. Mostly, they just waft the oxygen through those holes in their exoskeletons. Spiders, for example, kind of need to move to breathe (!) and their breath is kind of like... absorbing air through the holes in their bellies, as they stir up the air with their legs. And they don’t have blood or veins or lungs or muscles. They don’t have an active circulatory system. They just have loose sloshy amounts of hemolymph. The air gets as far as it gets into their bodies, and that’s it. They don’t have the same kind of oxygen-moving machinery. So there’s a limit to how much oxygen can passively penetrate into their interiors. And that EXACT limit is the upper limit for how big arthropods can get on this Earth. You don’t get giant spiders, because the arthropod body plan just doesn’t have the infrastructure to get big in our atmosphere.

Back in the day - the air WAS more oxygen-rich. And that’s probably why we had those iconic ENORMOUS DRAGONFLIES. The air had more oxygen, so it penetrated more deeply into their dark inner depths. So you got REALLY BIG BUGS back in the day. And someday, we may again!

But vertebrates are kind of “eh” about oxygen levels. They don’t really restrict our growth. In periods of safety and comfort and abundant food, vertebrates get big. There are various reasons for this. If you are very large, you can defend yourself from anything, access different food, stay warm in cold climates, and adapt to different environments. You can get into an arms race with your predators, where you’re both trying to be bigger or meaner.

Big vertebrates eat a fuckload, though. and they are DELICATE AF. You need a huge, thriving, delicately balanced ecosystem to develop really big terrestrial vertebrates. Big carnivores - like direwolves and sabretoothed cats - need massive amounts of meat. They need to be at the tops of HUGE food chains, in which there are thousands of even more enormous meaty beasts for them to eat. The enormous meaty beasts need massive amounts of vegetation to eat. Biomass is expensive.

And the maintenance on those things is ridiculous! The minute there’s a disaster, like a mass extinction or an Ice Age or an unexpected level of human, charismatic megafauna can’t make it, and they all drop dead. They are magnificent, but not nimble. They’re really dependent on always having the same habitat that they evolved in so they can get the food they need. They don’t really colonize new habitats. Usually, it’s the fierce little adaptable things that survive the big extinctions - little lizards, and birds, and rats, and little monkey things. Fierce little things breed really fast and get EVERYWHERE. A rat can thrive in a thousand different environments, but giraffes can only really exist on the African savannah. Giraffes could be erased from the planet without much effort, but rats will probably go with us into outer space. Or LEAD us into space.

The Native Americans watched while white invaders slaughtered the magnificent bison, an enormous primal beast that numbered in the millions, a beast that had survived the Ice Age without even blinking. A few years of butchery - not even a blip of geological time - and boom, gone, now the American bison is nearly extinct and will never again carpet the prairie. It went from possibly 60 million individuals to about a thousand in a few years of white people. Try playing extinction with something small. Try picturing that happening with rabbits.

Although I have FEELINGS about the causes of quaternary extinction event (which killed off many of the enormous prehistoric mammals, leaving the current ones we have today) it is certainly true that humans tend to repress the development of enormous mammals. In our lifetime, we might be the death of rhinos and elephants.

So in conclusion: higher oxygen levels in the past were possibly responsible for the development of giant arthropods. In the case of prehistoric animals, it’s more that animals tend to get big when times are good, and small when times are bad. The Ice Age was a bad time, and lots of iconic big things went extinct.

However, we do currently share the planet with the BIGGEST ANIMAL EVER TO BE - the blue whale. 

[spacenoirdetective]

Esteban Maroto

[savage-kult-of-gorthaur]

SPY-noh-SOAR-uss -- THE "SPINY LIZARD" OF PRESENT DAY NORTH AFRICA.

PIC INFO: Resolution at 1692x2508 -- Spotlight on Spinosaurus (meaning "spine lizard"), a genus of theropod dinosaur that lived in what now is North Africa during the upper Albian to upper Turonian stages of the Cretaceous period, about 112 to 93.5 million years ago.

The best known species is S. aegyptiacus from Egypt, although a potential second species, S. maroccanus, has been recovered from Morocco. Artwork by William Stout, c. 2000.

Name: Spinosaurus ‭(‬Spine lizard‭)‬

Phonetic: Spine-oh-sore-us.

Named By: Ernst Stromer‭ ‬-‭ ‬1915.

Synonyms: Sigilmassasaurus?

Classification: Chordata,‭ ‬Reptilia,‭ ‬Dinosauria,‭ ‬Saurischia,‭ ‬Theropoda,‭ ‬Megalosauroidea,‭ ‬Spinosauridae,‭ ‬Spinosaurinae.

Species: S.‭ ‬aegyptiacus‭ (‬type‭)‬,‭ ‬S.‭ ‬maroccanus is a possible second,‭ ‬although many consider this species as being the same as the type species.

Diet: Piscivore/Carnivore.

Size: Estimates highly variable amongst sources and range anywhere between 12.6 and 18 meters total body length. Skull length estimated between 1.5 and 1.75 meters long.

Known locations: North Africa,‭ ‬particularly Egypt‭ ‬-‭ ‬Bahariya Formation,‭ ‬and Morocco‭ ‬-‭ ‬Kem Kem Beds.

Time period: Albian to Cenomanian of the Cretaceous.

Fossil representation: To date at least six partial specimens of the skull,‭ ‬mandible,‭ ‬neural spines and other fragmentary post cranial remains.‭ ‬Teeth however are considerably more common.

Sources: www.prehistoric-wildlife.com/species/s/spinosaurus.html, www.mindat.org/taxon-4967112.html, & Pinterest.