Dirt_Owl

cross-posted from: https://hexbear.net/post/567338

I found this in my old posts. WTF lmao.

Are you a Pi male?

This perfect lad is Perucetus Colossus, a newly discovered 39-37 million year old fossil of an extinct whale that was even heavier than todays blue whale.

Look at that tiny head, remarkable.

[Wikipedia:]

Perucetus is an extinct genus of early whale from the Eocene of Peru. With an estimated length exceeding 17.0–20.1 meters (55.8–65.9 ft) and weight ranging from 85–340 t (84–335 long tons; 94–375 short tons), Perucetus may have rivalled, if not exceeded, the modern blue whale in weight. This is in part due to the incredibly thick and dense bones this animal possessed, coupled with its already great size. The ecology of Perucetus, however, remains largely mysterious. Based on the fossils, it was likely a slow-moving inhabitant of shallow waters. Its diet can only be speculated upon, but one suggestion proposes that it may have fed on benthic animals like crustaceans and molluscs that live on the ocean floor. Only a single species is currently known, P. colossus.

The most characteristic feature of Perucetus is the high degree of pachyosteosclerosis present in the bones of the body, which means that the bones are simultaneously thicker (pachyostotic) and denser (osteosclerotic) than in any other known cetacean. Due to pachyostosis, the vertebrae are greatly inflated, making them nearly twice as voluminous as those of a 25 m (82 ft) long blue whale. The increase in bone mass is also observed in the microanatomy of the bone. The ribs are entirely composed of dense bone and lack the medullary cavity seen in the bones of other animals. The vascular channels that penetrate the bone are narrow, not only indicating the maturity of the animal but also adding to the already dense nature of the bones.

Perucetus may have ranged in weight from 85–340 t (84–335 long tons; 94–375 short tons) with an average of 180 t (180 long tons; 200 short tons). The 17–20-meter (56–66 ft) skeletal structure alone would have accounted for 5.3–7.6 t (5.2–7.5 long tons; 5.8–8.4 short tons), which is already two to three times the weight of the skeleton of a 25 m (82 ft) long blue whale. The weight estimates are based around the relation between skeletal and total body mass of modern mammals. Notably, whales have much lighter skeletons compared to their total mass, whereas sirenians (dugongs and manatees) are similar to land mammals in having much denser skeletons that contribute more to their total weight. Bianucci and colleagues note the difficulties in determining the weight of basilosaurids. They suggest that the increase in skeletal mass could have been compensated for by larger amounts of blubber, which is less dense than other soft tissue. Ultimately, extreme values were used in the calculations, leading to the wide range for the weight estimate present in the type description. Basing the math on sirenians, a weight of 85 t (84 long tons; 94 short tons) was calculated. Combining the lowest skeletal-weight–to–total-weight ratio found in cetaceans with the highest estimated skeletal mass yields a weight of up to 340 t (330 long tons; 370 short tons). Mean values, on the other hand, result in a weight of 180 t (180 long tons; 200 short tons). This may indicate that, although not as long, the species could have been heavier than modern blue whales.

The immense size and bone density both make it impossible for Perucetus to have gone on land, which is in line with its classification as a basilosaurid. The pachyosteosclerosis is taken as a sign that Perucetus lived in shallow waters, using it as buoyancy control as modern manatees do. Given its size and weight, Perucetus could have resisted crashing waves in more turbulent waters, something inferred for the similarly buoyant Steller's sea cow. The animal's affinity for shallow waters is congruent with the interpretation that basilosaurids preferred coastal waters, rather than living in the open ocean.

While the fragmentary nature of this animal renders precise statements on its locomotion uncertain, some suggestions have been made. The elongated centra of the vertebrae for instance may suggest that it, like manatees but not dugongs, swam with the use of axial undulation. This further indicates shallow waters rather than pelagic habitats for the animal. The great size of the vertebrae does impose limits on the swimming style of Perucetus, as does the shape of the transverse processes of the vertebrae. Using the methods of a previous study would suggest that Perucetus was limited in its ability to flex upwards and from side to side but possessed an increased ability to flex downward (ventrally). This could suggest that Perucetus swam with slow up and down movements of its tail while not making use of any side to side movements as has been suggested for Basilosaurus. The strong ventral flexion in particular may have been of great importance for the animal when pushing itself off the ocean floor in order to breathe at the surface. The precise function of this combination of pachyosteosclerosis and gigantism is not fully understood, but may be linked to the energetic cost of undulating movements or the ability to dive for longer periods of time.

The diet and feeding style remain even more mysterious, since no skull material of this animal is currently known. Still, some possibilities can be inferred based on the lifestyle deduced from the postcrania. While the many noted similarities to sirenians could be taken as a sign of a grazing lifestyle, this notion is deemed unlikely, as no other cetacean is known to have been herbivorous. It is deemed more likely that Perucetus fed on molluscs, crustaceans and other animals on the sea floor, either through suction feeding or filter feeding. Such a lifestyle would be comparable to that of the modern grey whale. Another hypothesis mentioned by Bianucci et al. is that Perucetus could have been a scavenger like large demersal sharks. Ultimately, until better material is found, the precise ecology of Perucetus will remain unknown.

My new favorite extinct animal. No one steal him, hes my new best friend.

[EDIT: IGNORE THIS. I FIXED IT BY CHANGING THE BOOT MODE TO AHCI AND THEN UNINSTALLING THE OFFENDING UPDATES IN THE SAFE MENU]

Scientists excavating in a Peruvian desert have found the fossilized bones of what they argue may have been the heaviest animal ever to live: a strange ancient whale that may have had a teensy head attached to a giant, bloated body.

The long-lost whale, now dubbed Perucetus colossus, had a skeleton that may have weighed two to three times that of a blue whale. Tipping the scales at up to 330,000 pounds, the blue whale is the heaviest animal alive today. Until now, paleontologists hadn’t found anything that could even compare to that behemoth.

“It’s an extraordinary claim—the heaviest animal yet described—so that requires pretty extraordinary evidence, and I think they convincingly demonstrated that,” says Annalisa Berta, a retired paleontologist and a professor emerita at San Diego State University, who was not involved in the new research. The study was published on August 2 in the journal Nature.

Paleontologist and study co-author Mario Urbina first stumbled on one of P. colossus’s vertebrae around a decade ago, says his colleague Rodolfo Salas-Gismondi, a paleontologist at Cayetano Heredia University in Peru, who is also a co-author of the paper. Urbina believed he’d found a fossil, but Salas-Gismondi wasn’t convinced. “I was skeptical about these fossils. I said to him, ‘It doesn’t look like real bone,’” Salas-Gismondi says, noting that the structure of the bone was very different from most finds. “It looked like a rock, in fact.”

But analyses showed that Urbina was correct. And since the initial find, the team has excavated 13 vertebrae, four ribs and part of a hip. The vertebrae are so weighty that the team could excavate only one or two each year, Salas-Gismondi says. “An animal of this size has never been found before in the fossil record anywhere in the world,” he says.

Other scientists agree that the bones are unprecedented. “It’s an astonishing specimen,” says Philip Gingerich, a paleontologist at the University of Michigan, who was not involved in the new research. “These vertebrae are nearly the size of beer kegs or something. They’re unlike anything certainly that I’ve ever seen—that anyone’s ever seen.”

As described by Salas-Gismondi and his colleagues, the fossils are extremely massive in two different ways. First, they are particularly dense. Bones usually have a spongy structure, but these have deposits filling those pores—hence his initial reaction that the vertebra fossil looked like a rock. Second, the bones are large and look like they’ve been inflated.

“It’s just incredibly bulbous,” says Emily Buchholtz, a paleontologist at Wellesley College, referring to a vertebra pictured in the paper. “I’ve never seen anything like it,” she adds, noting that blue whale vertebrae are also massive but sleek, whereas the bones of P. colossus are swollen.

Salas-Gismondi and his colleagues argue that the bones’ incredible mass represents an adaptation to coastal living in shallow waters. The dense bones, the researchers say, balanced the buoyancy of blubber and lungs filled with air—essentially they acted as ballast to let P. colossus whales remain underwater with less effort. “Scuba divers put on weight belts,” Berta says. “What these whales did was: they increased the density of their bones.”

The bones are nearly 40 million years old, which means the bizarre animal would have swam the seas just a couple of million years before primitive whales began their evolutionary split into the toothed and baleen whales we know today.

But scientists can’t know what P. colossus ate—or much else about how it lived—because they have only excavated the core of the body. “They’ve got the middle of the skeleton. I think they need the front end of it or the back end of it before we’ll really understand what this thing was doing,” Gingerich says. newsletter promo

For now, the researchers have filled in the gaps about P. colossus’s appearance by using what they know from its less extreme relatives. These animals tended to have a small head, which the scientists incorporated into the reconstruction, although they emphasize that the picture is speculative.

All known cetaceans—whales, dolphins and porpoises—are carnivores, so the scientists assume the massive whale was, too. But it would have needed an incredible amount of fuel to survive. Today’s blue whales eat tiny crustaceans called krill. The whales feast on massive numbers of krill to make up for their meager serving size, but near-coast waters can’t support large populations of animals, even small ones.

“I do like the hypothesis of a large scavenger that would just eat sunken carcasses,” says study co-author Eli Amson, a paleontologist at the State Museum of Natural History Stuttgart in Germany. “But it would be a first for a cetacean; that’s really weird.” Another possibility is that P. colossus was vegetarian like the manatees whose silhouette it echoes, although Amson says that would be even stranger. But without teeth or a jaw, everything is guesswork.

The skeleton was found with its head pointing into a hillside, and the researchers still hope to find the funding to uncover more of the lost animal. In the meantime, the bones excavated to date will reside at the Natural History Museum in Lima, Peru, where both Salas-Gismondi and Urbina work. There they will first be on display for a few months and will then move behind the scenes.

And scientists will continue to marvel at the evolutionary mysteries the bones pose. “Basically,” Buchholtz says, “my entire reaction to this is: ‘Oh wow. Oh wow.’”

SHUT THE FUCK UP AND LEARN SOMETHING NERDS. TIME FOR SOME BIRD FACTS

The Cuban giant owl or giant cursorial owl is an extinct genus of giant owl that measured 1.1 metres in height. It is closely related to the many species of living owls of the genus Strix. It was a flightless or nearly flightless bird and it is believed to be the largest owl that ever existed. It lived on the island of Cuba.

The first fossil specimen was mistakenly described as a bird in the family Phorusrhacidae, in part because the bones were so large. In 1961, Pierce Brodkorb reviewed the findings and placed them properly, with the owls. Remains have been abundant throughout the island, in cave deposits from the Late Pleistocene period (10,000s of years ago) and at least three nearly complete skeletons have been found.

Arredondo estimated the height of Ornimegalonyx to have been 1.1 metres tall and it probably easily exceeded 9 kilograms. It had very long legs for its size, but was bulky overall and probably short-tailed. The modern owl that most resembles the Cuban giant owl in proportions is probably the dainty burrowing owl, the only surviving owl closely tied to the ground. This implies similar adaptations to the terrestrial lifestyle, but not a close phylogenetic relationship.

One of the largest living owl, the Eurasian eagle owl (Bubo bubo), reaches 4 kg in weight, and Peters (page 188) has reported them taking roe deer fawns that weigh 17 kg as prey. This suggests that Ornimegalonyx could have killed prey of 35 kg or more. Modern owls are known to use a pouncing strategy - where they drop from elevated perches onto prey, spreading their wings only just before hitting their target. The modern kakapo (Strigops habroptila) is a flightless island parrot and is convergent, in some ways, with owls. Like Ornimegalonyx, it is the largest and heaviest member of its order, it has reduced wings, and a reduced keel of the sternum, but it can parachute by leaping from trees with its wings outspread, potentially covering several meters at an angle of descent less than 45 degrees.

The legs and feet of the Cuban giant owl appear to be very large and powerfully built. This supports the theory that they were strong runners, hence the alternate name, cursorial. The keel of the sternum was reduced and the owl may have been capable of short burst of flight. It is probable that, like a modern wild turkey, the owl only took flight when extremely pressed, more often choosing to run.

The Cuban giant owl is believed to have preyed principally on large rodents including Heteropsomys, Capromys, Geocapromys, and Macrocapromys (the size of modern nutria or capybara) and the ground sloths Cubanocnus, Miocnus, Mesocnus, and Megalocnus. It was probably an ambush predator that would pounce on unsuspecting prey with its crushing talons.

VIVA LA CUBA

Wow I can't believe that cops evolved from these 😱