Been a long week so let’s have a good #FossilFriday. Today some shots from my trip to the Smithsonian Natural History Museum. The dinosaur wing is amazing and generally a great meshed I wish I could have spent more time at.

#dinosaur #paleontology #fossil #synapsids #MegaFauna

This is a silk floss tree. It stands on campus outside our department building. It is believed that the silk floss tree developed its spikes as protection against megafauna, especially mega sloths. 🤯🤯🤯 I mean, what am I supposed to do with awesome information like that? I think I’m going to have to lie down. Someone fetch me my smelling salts. 🦥🦥🦥 @academicchatter #sloths #megafauna #florida #miami #trees #treesofmastodon

I can't get the damn picture to flip! Oh well, highly recommended book of the day is The Rise and Reign of the Mammals by Steve Brusatte. Companion to the Rise and Fall of Dinosaurs.

#books #book #bookstoot #bookstodon #BookOfTheDay #mammals #paleontology #dinosaurs #stevebrusatte #science #mammoths #mastodon #sabretooth #megafauna #continentaldrift #Paleoclimates #theriseandreignofthemammals

A bear, a bear, all brown and black and covered with hair! (Well, a black bear.)

#megafauna

@ttiurani @wlach @breadandcircuses Humans have been destroying ecosystems at least since we took up farming, if I understand my reading correctly. It might be in our nature.

I know that it is not a given that our hunting ancestors exterminated the #megafauna, but doesn't it seem likely at least? Just to illustrate what our species is like.

thylacoleo #paleoart #australia #art #megafauna

#paleoanthropology #anthropology #megafauna

https://phys.org/news/2023-06-paleo-americans-mastodons-mammoths-megafauna-eastern.html

When I was a kid, I loved to read about Australia's extinct megafauna. It seem there was a giant Pleistocene version of just about everything - giant wombats, giant koalas, giant echidnas, giant goannas. So I imagined for myself a fantasy megafaunal version of my favourite lizards - the bluetongues in the genus Tiliqua. Now they are a reality.
https://theconversation.com/meet-the-biggest-and-most-bizarre-skink-ever-found-in-australia-it-became-extinct-47-000-years-ago-206764

#MegaFauna #Tiliqua

Today’s #megafauna is the #gorilla. The largest living #primate, the gorilla stands 4-6 feet tall and weighs up to 440 lbs. It is the third most closely-related species to humans (after chimpanzees and bonobos), and is native to central Africa. Gorillas play an important role in their rain forest ecosystems–by walking around they clear space for sun-loving plants for thrive. Humans in the Congo basin depend on the same forest as the gorillas, and rain generated by this forest falls worldwide, making it a critical target for conservation efforts.

Gorillas live in troops of 2-30 individuals. The makeup of these troops is fluid, and both male and female gorillas can leave and join different groups throughout their lifetimes. Troops are usually lead by an older male–or silverback–who determines the group’s routine and helps to mediate disputes. Gorillas--like humans--are playful, and often engage in play with other members of their group. Play is most common in young gorillas as they start to venture further from their mothers, but adults--including the silverback--will also engage in play! Wrestling is a common form of play (and not to be mistaken for aggression), but gorillas sometimes play with themselves by swinging from branches or rolling down hills.

Gorillas build nests by tucking branches and foliage around themselves. Nests are used both to rest in during the day and to sleep in at night. Nighttime nests are usually made close to the last place that the troop fed, and are sometimes made from the gorillas' uneaten food. Infant gorillas share nests with their mothers, while juveniles over 3 are likely to nest in trees. Adults--especially males--are more likely to build their nests on the ground.

Tuesday’s #megafauna is xiphactinus, a #fish that lived between 112 and 65 million years ago. At up to 20 feet long, it is one of the largest bony fish to ever have lived. Its long, slender body would have allowed it to travel at high speeds, reaching 37 miles per hour. Its fanlike pectoral fins and large tail fin made it a powerful swimmer, capable of leaping from the water (like modern-day dolphins.) This has led to speculation that #xiphactinus could prey on pterosaurs by snatching them from the sky.

Whether or not the behemoth fish ate pterosaurs, it was definitely a voracious predator. Its sharp teeth and large size would have allowed it to feed on many smaller animals in the ocean, including fish, turtles, and even young mosasaurs. In one of the images below, a 13-foot-long xiphactinus skeleton contains the 6-foot long skeleton of a smaller fish–its last meal. However, another image shows a xiphactinus skeleton within the remains of a large shark--also xiphactinus's last meal, in a sense. Despite its appetite, xiphactinus was not an apex predator of the inland sea, and did sometimes fall prey to other, more vicious megafauna.

Today’s #megafauna is the giant #panda! They are the rarest extant #bears, with only 1,864 living in the wild. Pandas can weigh over 300 pounds and stand about 4 feet tall. In order to maintain their large frames, can consume up to 84 pounds of bamboo each day. Although they have the digestive system of a carnivore, giant pandas are exclusively herbivores. They live in the mountain forests of southwestern China.

Giant pandas’ native Yangtze valley is an unusually biodiverse ecosystem for its temperate climate, and fluffy pandas fill an important ecological role. Their fluffy fur gathers pollen and seeds, aiding with pollination and seed dispersal. Despite their stout bodies, pandas can also be excellent climbers, which spreads pollen and seeds even further. The best panda climbers use their heads to stabilize their climb and maintain their balance.

Pandas can live for about 20 years in the wild, and have a very low birthrate–one female may raise only 5-8 cubs to maturity throughout her lifetime. This, combined with habitat loss and fragmentation threatens the survival of the species. However, conservation efforts do seem to be working, as pandas are now significantly less threatened by hunting and their population is rising.

Today’s #megafauna is the #cryodrakon! This large #pterosaur lived in Alberta, Canada between 74 and 77 million years ago. At the time, the land supported a temperate forest that would have provided the cryodrakon with plenty of mammals, lizards, and baby dinosaurs to snack on. Like #quetzelcoatlus, cryodrakon was a member of azhdarchidae: a family of late #cretaceous pterosaurs characterized by long legs and necks. Most members of this family are very large, and cryodrakon had a wingspan of 33 feet.

For a long time, cryodrakon fossils were confused for quetzelcoatlus fossils. This was exacerbated by the delayed publication of a full description of quetzelcoatlus. However, the discovery of several European azhdarchidae species allowed for additional differentiation. When the original quetzelcoatlus bones became available to view, it became clear that cryodrakon was species distinct from its Southern cousin. In fact, crydrakon was apparently more robust than quetzelcoatlus, making it perhaps the largest pterosaur ever.

Today’s #megafauna is the world’s largest #rodent: the capybara! Standing 2 feet tall at the shoulder, reaching lengths over 4.5 feet, and weighing up to 143 lbs, this fuzzy critter is nearly twice as big as the next-largest extant rodent (the North American beaver.) Native to South America’s #wetlands and forests, the #capybara is well-adapted for swimming. Its eyes, ears, and nostrils are all near the top of its head, which lets it submerge in order to hide from predators. In addition, it is able to hold its breath for up to 5 minutes, and its webbed feet can get it going quite fast in water.

On land, the capybara can run up to 22 miles per hour. It spends most of its time in herds of several dozen, with one dominant male living amongst several females and pups. These herds live in well-established home ranges which can fluctuate in size to provide sufficient food for the whole herd. During the day, the nocturnal capybara rests on riverbanks or in mud wallows. At night, it grazes on grasses and aquatic plants. Since these can be tough to break down, the capybara will eat its own feces in order to further digest its food. Worldwide capybara populations are stable, though they are hunted by humans in some areas for both meat and skin. Other predators of the capybara include caiman, wildcats, snakes, and even eagles.

Recycling one of my favorite #megafauna--the king #amphibian--mastodonsaurus! I was delighted to find one in the American Museum of Natural History last week. #Mastodonsaurus was the largest amphibian to ever live, and dominated European rivers about 250-200 million years ago.

Mastodonsaurus is not related to modern crocodiles, but it likely filled a similar role. Its little legs were likely too weak to support its hefty on land, meaning mastodonsaurus was aquatic. However, it was well-suited to the murky waters of Triassic European rivers, with nostrils that allowed it to breathe air while the rest of it was fully submerged, and with the ability to sense pressure waves from nearby swimming prey.

And there is little doubt that it did catch its prey, since its skull supported strong muscles and many, pointy teeth--including two elongated front tusks that poked out through the top of its head!

Mastodonsaurus was likely an apex predator due to its size--it could grow up to 20 feet long, with 1/6 of that length in its head. Such a large skull would have required mastodonsaurus to tilt its head all the way back in order to fully open its mouth.

Today’s #megafauna is the #daeodon–a giant, pig-like mammal that lived 29-19 million years ago. Although it looks similar to a wild boar, it is not related to modern-day #pigs. At the back of its long jaw are supports for powerful muscles that would have made the daeodon’s bite force very strong–enabling it to bite through bones. The varied shape of its teeth suggests that daedon was an omnivore. Multiple #fossils have been found with daedon tooth marks scratched into their bones.

Arguments have been made that daedon was actually a carrion scavenger. Its nostrils are located on the side of the face, allowing its sense of smell to be directional–much in the same way that a human’s sense of sound is directional because one ear can hear a sound before the other does. Zigazagging fossil footprints suggest that daedon wandered around, potentially sniffing for fresh kills to scavenge.

Daedon stood about size feet tall at the shoulder and was 9 feet long, weighing in at up to 2000 lbs. Whether it scavenged meat for most of its meals or just did so as an opportunistic omnivore, daeodon’s hulking size likely helped it to withstand attacks from other #animals and conflict within its own species.

Today’s #megafauna is the goldencrowned flying fox–a species of #megabat that lives in the Philippines. Its diet consists entirely of fruit, and it plays an important role in seed distribution in the forest ecosystem. This bat also happily lives near human settlements, as long as hunting and industrial forest disturbance are kept at bay.

Weighing in at under 3 pounds, the flying fox nevertheless has a wingspan of nearly 6 feet. These massive wings help the nocturnal bat to cover great distances in search of food–sometimes as many as 25 miles per night. As it flies, the bat relies on its excellent eyesight–not echolocation!–to spot food.

Flying foxes can congregate into huge colonies, sometimes recorded as numbering in the tens of thousands. This protects them from cold and predators. Unfortunately, the biggest threat to the flying fox’s survival is human activity. 90% of old-growth forests in the Philippines have been destroyed, and flying foxes are still hunted for meat. These two factors have driven the flying fox population down to 10-20,000 individuals, and the species remains endangered.

Today for #MegafaunaMay, we have the Japanese spider #crab! While this gangly crustacean’s hard carapace reaches a maximum of about 1 foot in width, its legs continue to grow through adulthood and can span more than 12 feet from claw to claw. Like all crabs, it has eight walking limbs and two clawed limbs. The spider crab’s elongated legs help it to scuttle around on the ocean floor off the coast of Japan, scavenging for their food.

Unfortunately, these long legs are quite fragile, and the crabs are often found with missing legs. In fact, spider crabs have been observed walking with as few as five of their walking limbs intact. Fishing nets often rip the legs off as they pass. Luckily, crabs molt periodically, and can regrow their legs during this process.

Most of the time, this #megafauna is difficult prey. Its size and claws help protect it. Immediately after molting, it is slightly more vulnerable to predators such as octopi, which can take advantage of its still-soft new shell. Young, small individuals can also be at risk, but will decorate their shells with kelp and sea sponges as a form of camouflage.

Most of the time, adult spider crabs inhabit depths between 500 and 1000 feet, though they have been found as deep as 2000 feet. They move to shallower waters in order to spawn. The warmer temperature closer to the surface is ideal for helping young crabs grow. Female spider crabs will incubate eggs until they hatch, and then retreat back into the depths. Young spider crabs are usually found in the shallows, and move deeper as they age.

Happy #megafauna #MayTheFourth! Today’s megafauna is megalania, an ice-age monitor #lizard that could grow 16 feet long. The massive monitor lizard lived in Australia in various habitats including forests and grasslands. Its fossils are rare, and mostly made up of skulls. These skulls tell us that megalania sported an unusual ridge along its snout andbony plates on its head and neck that may have protected it in fights. Its sharp teeth leave little doubt that it was a formidable predator.

Kangaroo remains are often found near megalania fossils, suggesting that megalania was very capable of taking down large prey. Other potential food sources may have included large flightless birds and even other reptiles. It is possible that this lizard had hunting habits similar to its relative, the modern #KomodoDragon. Although neither megalania nor the komodo dragon are built for speed, komodo dragons only need to land one bite on their prey in order to kill them, as their toxic saliva leads to terminal infections. It is possible that megalania may have had similar capabilities.

Perhaps due to its impressive size and relatively recent existence, megalania is a popularly reported cryptozoological sighting in Australia. Fans believe that Australia’s extensive wilderness provides hiding for the shy giants, who venture near humans only to devour cattle and horses. While evidence for this megafauna as an extant cryptid is limited, its existence in Australia did overlap with humanity’s–and the idea of any human, past or present, facing down a 16-foot lizard is certainly terrifying.

For this third day of #MegafaunaMay, we are looking at the #hippopotamus. This #megafauna can weigh up to 10,000 pounds and reach over 16 feet in length. Although its social systems revolve around access to water, it is also adapted to land, able to run hundreds of yards at speeds approaching 20 mph. These massive herbivores also rely on water to cool themselves, as their skin secretes red sunscreen instead of sweat.

#Hippos are very social, and spend their days resting in pools of water with their herds. They communicate with a wide variety of sounds, including a warning honk which can reach 115 decibels–about as loud as a siren–and produces sound in both air and water at the same time. At night, hippopotamus herds leave their pools to graze on grasses, consuming over 1% of their body weight and returning to their pools by dawn. Male hippos are protective of their herds, resting on the outside edges of pools while females control the center. Males will fight for dominance and use their large, flat tails to spread dung around, marking their territories.

Although hippos rarely eat meat, they possess formidable incisors which are used for defense and fighting. Hippopotami can open their jaws to a whopping 150 degrees wide, and can snap them shut with over 8000 newtons newtons of bite force, making them one of the most dangerous animals to humans–though most hippo attacks occur when humans get too close to young or pregnant members of a herd.

On this second day of #MegafaunaMay, our daily #megafauna is quetzelcoatlus. Named after the feathered serpent god of the Aztec religion, this gigantic #pterosaur lived during the late Cretaceous period in modern-day North America.

With a maximum weight over 500lbs and a wingspan over 30 feet wide, #quetzelcoatlus has inspired controversy over its flight capabilities. For some, its massive size sheds doubt on the idea that it ever flew, but aerodynamic models suggest that it was, in fact, the largest flying animal known to have existed. The towering pterosaur was originally thought to have flown like modern condors by soaring on thermal updrafts in the air. However, more recent research suggests that it instead has more in common with the kori bustard, using its strong wing muscles to complete short, low flights.

Even short flights are impressive from such a heavy animal, and the wings had to be very wide in order to allow them. In fact, quetzelcoatlus’s wingspan is so long that its folded wings touched the ground when it stood on its 6-foot tall legs. This gave the pterosaur a unique approach to walking: each wing had to be moved out of the way of its corresponding foot with each step it too.

Like other #pterosaurs, this species had hollow bones, so its fragile remains are rarer finds than those of contemporary dinosaurs such as the T-Rex. Skulls have given us many hints about quetzelcoatlus’s lifestyle: its large eye sockets suggest that had excellent eyesight; its beak suggests a diet of creatures skimmed out of the lakes near where its fossils have been found; and a bony crest on top of its head could potentially have been used for attracting mates or controlling flight. Although we do not have a complete skeleton of quetzelcoatlus, reconstructions and comparisons to modern species have allowed us to fill in the gaps.