101 replies to this topic

[wjfox]

I can't believe we don't have a thread for this already. Here we can post general articles, pics, videos or discussions about dinosaurs and other prehistoric life. Since it's a fairly broad and important topic, I've pinned it.

 

I'll start with this AMAZING (and slightly scary) image...

 

Quetzalcoatlus northropi, the largest known flying animal. Lived from 72 million to 66 million years ago.

 

 

 

 

 

 

 

Oh, and here's Meganeuropsis, the largest flying insect...

 

These were able to survive only because Earth's atmosphere had a lot more oxygen back then (283.5–290.1 mya).

 

 

 

 

 

[zEVerzan]

Quetzalcoatlus has long been a fascination of mine because it was basically a *flying carnivorous giraffe*. It could absolutely swallow a human in one bite if it wanted. I'll do some digging and see if I can find an old sketch of Quetzalcoatlus I animated.

[Raklian]

Quetzalcoatlus has long been a fascination of mine because it was basically a *flying carnivorous giraffe*. It could absolutely swallow a human in one bite if it wanted. I'll do some digging and see if I can find an old sketch of Quetzalcoatlus I animated.

 

I've always wondered how that monster is able to support such a large head with a tiny thorax, let alone fly it. Heck, giraffes have tiny heads so supporting their heads with long thin necks wasn't so out of the realm.

 

I guess the Quetzalcoatlus' reverse-bending forelegs have to support the body's forward center of gravity due to the apparent greater mass in the head-neck section, hence the crawling behavior of this creature when it's not flying.

[wjfox]

The short-faced bear.

 

Scientists speculate that these delayed human migration into North America, because they hunted us in the Bering Strait.

 

 

[TranscendingGod]

https://www.npr.org/...s-to-extinction

 

We got em in the end though.

[zEVerzan]

I'll do some digging and see if I can find an old sketch of Quetzalcoatlus I animated.

 

I found it:

 

https://i.imgur.com/EH1lIHI.gif

 

It won't let me post as a gif :\ 

[Time_Traveller]

Fossil of 'first giant' dinosaur discovered in Argentina

 

10 July 2018

 

They are the biggest animals to have walked the Earth, with some weighing as much as a space shuttle.

 

However, it is unclear how dinosaurs grew to such massive proportions.

 

A new dinosaur discovery from Argentina gives fresh evidence on the rise of the giants.

 

The animal used a novel strategy to become super-sized, involving very fast growth spurts and efficient bird-like lungs, say palaeontologists.

 

The fossil was found in the northwest of Argentina during a field trip. The scientists found four skeletons in all, one of a new species and three of related dinosaurs.

 

https://www.bbc.co.u...onment-44744153

[wjfox]

These half-billion-year-old creatures were animals—but unlike any known today

 

Aug. 8, 2018 , 7:00 AM

 

So-called Ediacaran organisms have puzzled biologists for decades. To the untrained eye they look like fossilized plants, in tube or frond shapes up to 2 meters long. These strange life forms dominated Earth’s seas half a billion years ago, and scientists have long struggled to figure out whether they’re algae, fungi, or even an entirely different kingdom of life that failed to survive. Now, two paleontologists think they have finally established the identity of the mysterious creatures: They were animals, some of which could move around, but they were unlike any living on Earth today.

 

Read more: http://www.sciencema...any-known-today

 

 

[wjfox]

The Elephant Bird Regains Its Title as the Largest Bird That Ever Lived

 

Sept. 26, 2018

 

History has not been kind to the elephant bird of Madagascar. Standing nearly 10 feet tall and weighing up to 1,000 pounds — or so researchers believed — this flightless cousin of the ostrich went extinct in the 17th century, thanks in part to humans stealing their massive eggs, either to feed their own families or to repurpose them as giant rum flasks. Or both.

More recently, the bird’s designation as the heaviest in history was challenged by the discovery of the slightly larger, unrelated Dromornis stirtoni, an Australian flightless giant that went extinct 20,000 years ago.

But a new study seeks to restore the elephant bird’s heavyweight title. After taxonomic reshuffling and examination of collected elephant bird remains, researchers say that a member of a previously unidentified genus of the birds could have weighed more than 1,700 pounds, making it by far the largest bird ever known.

 

https://www.nytimes....phant-bird.html

 

 

[wjfox]

Fossil of gigantic ‘mammal-like’ reptile which co-existed with dinosaurs discovered in Poland

 

The discovery of an enormous pre-historic animal, which lived during the Triassic period 200 million years ago, indicates early dinosaurs were not the only group growing to large sizes at the time.

Though dinosaurs went on to dominate the subsequent Jurassic era, a group known as therapsids, which are the ancestors of all modern mammals, thrived even before the dinosaurs’ reign.

The fossilised remains of a mammal-like reptile discovered in Poland reveal a creature which weighed nine tonnes and stood as tall as an elephant.

Scientists have identified the remains as a type of dicynodont from the therapsid group and have named the species Lisowicia bojani, after the Polish village of Lisowice close to where the fossils were found, and a German anatomist named Ludwig Heinrich Bojanus.

Dicynodonts were herbivores and their sizes ranged from small burrowing species to large browsers. Most of them were also toothless. Despite their reptilian heritage, they are the predecessors of all modern mammals, including humans.

 

https://www.independ...y-a8646746.html

 

 

[Erowind]

/\

There are about 30 generations per 1,000 years.

Doing the math here.

30 * 1,000 = 30,000 generations for a million years.

30,000 * 200 for two-hundred million leaves us with 6,000,000 generations.

Say hello to everyone's 6,000,000 generation old grandparents everyone!

Granted life expectancy would be different for each distinct animal in our family trees, but the illustration still works. That Dicynodonts is everyone's grandmother/grandfather.

[wjfox]

/\

There are about 30 generations per 1,000 years.

Doing the math here.

30 * 1,000 = 30,000 generations for a million years.

30,000 * 200 for two-hundred million leaves us with 6,000,000 generations.

Say hello to everyone's 6,000,000 generation old grandparents everyone!

Granted life expectancy would be different for each distinct animal in our family trees, but the illustration still works. That Dicynodonts is everyone's grandmother/grandfather.

 

Amazing, isn't it. Richard Dawkins uses the same comparison in The Ancestor's Tale (one of my favourite books), going right back to the first single-celled organism!

[Sciencerocks]

Soft tissue shows Jurassic ichthyosaur was warm-blooded, had blubber and camouflage
December 5, 2018, North Carolina State University

An ancient, dolphin-like marine reptile resembles its distant relative in more than appearance, according to an international team of researchers that includes scientists from North Carolina State University and Sweden's Lund University. Molecular and microstructural analysis of a Stenopterygius ichthyosaur from the Jurassic (180 million years ago) reveals that these animals were most likely warm-blooded, had insulating blubber and used their coloration as camouflage from predators.

"Ichthyosaurs are interesting because they have many traits in common with dolphins, but are not at all closely related to those sea-dwelling mammals," says research co-author Mary Schweitzer, professor of biological sciences at NC State with a joint appointment at the North Carolina Museum of Natural Sciences and visiting professor at Lund University. "We aren't exactly sure of their biology either. They have many features in common with living marine reptiles like sea turtles, but we know from the fossil record that they gave live birth, which is associated with warm-bloodedness. This study reveals some of those biological mysteries."

 

Read more at: https://phys.org/new...looded.html#jCp

[caltrek]

So what killed the critters?

 

The Chilling Regularity of Mass Extinctions

 

https://www.theatlantic.com/science/archive/2015/11/the-next-mass-extinction/413884/

 

 

Introduction:

(The Atlantic) One thing we know for sure is that conditions on Earth were, shall we say, unpleasant for the dinosaurs at the moment of their demise. Alternate and overlapping theories suggest the great beasts were pelted with monster comets, drowned by mega-tsunamis, scorched with lava, starved by a landscape stripped of vegetation, blasted with the radiation of a dying supernova, cloaked in decades of darkness, and frozen in an ice age.

 

Now, a pair of researchers have new evidence to support a link between cyclical comet showers and mass extinctions, including the one that they believe wiped out the dinosaurs 66 million years ago. Michael Rampino, a geologist at New York University, and Ken Caldeira, an atmospheric scientist at the Carnegie Institution for Science, traced 260 million years of mass extinctions and found a familiar pattern: Every 26 million years, there were huge impacts and major die-offs. Their work was accepted by the Monthly Notices of the Royal Astronomical Society in September.

 

In recent decades, researchers using other methods have found evidence for a 26-million-year cycle of extinction on Earth, but the idea has remained controversial and unexplained. “I believe that our study, using revised dating of extinctions and craters, and a new method of spectral analysis, is strong evidence for the cycles,” Rampino told me.

 

Other scientists who have researched mass extinctions are more measured about the latest findings. “I’m sort of agnostic [about the larger theory],” said Paul Renne, the director of Berkeley Geochronology Center. “But I was really disappointed to see they used an age-database for the craters which is full of outdated information.”

 

Renne is the author of another new study that focuses on the Chicxulub crater, the massive divot beneath the Yucatán Peninsula that was created by the same impact blamed for the extinction of the dinosaurs. Renne and his colleagues believe that the comet or asteroid that blasted into Earth and made Chicxulub also set off a global chain-reaction of volcanic eruptions that accelerated the end of the dinosaurs. Volcanoes were, they believe, erupting continuously for millions of years. Long enough to make Hawaii’s Kilauea, which has been flowing since 1983, seem laughable. (“Kilauea is nothing,” Renne told me. “Kilauea is a flea.”)

 

An artist's rendering of an asteroid or comet striking Earth.

ANDREA DANTI / SHUTTERSTOCK

[caltrek]

^^^^^I know, I know, this is really old news.  Even the article is a bit dated.  Still, I have a 1986 book in my library which basically lays out the same idea. I was curious what more modern literature has to say on the subject.  Also, this is in the History section. 

[Sciencerocks]

Medical scanner helps to unlock the mysteries of a giant prehistoric marine reptile
January 8, 2019, University of Manchester
 

A nearly metre-long skull of a giant fossil marine ichthyosaur found in a farmer's field more than 60 years ago has been studied for the first time.

Using cutting-edge computerised tomography (CT) scanning technology, the research reveals new information including details of the rarely preserved braincase.

The almost 200 million year old fossil, which was found in 1955 at Fell Mill Farm in Warwickshire, had never formally been studied prior to this research.

Now, thanks to data collected from CT scans, the research team were able to digitally reconstruct the entire skull in 3-D. It is the first time a digital reconstruction of a skull and mandible of a large marine reptile has ever been made available for research purposes and to the public.

 

Read more at: https://phys.org/new...storic.html#jCp

[Sciencerocks]

Times of India
‏Verified account @timesofindia
2m2 minutes ago

IIT-Kharagpur researchers dig up signs of life in India from 2.5 bn yrs ago http://toi.in/YOEkta/a24gk

[Sciencerocks]

Fossilized slime of 100-million-year-old hagfish shakes up vertebrate family tree
January 21, 2019, University of Chicago Medical Center

Paleontologists at the University of Chicago have discovered the first detailed fossil of a hagfish, the slimy, eel-like carrion feeders of the ocean. The 100-million-year-old fossil helps answer questions about when these ancient, jawless fish branched off the evolutionary tree from the lineage that gave rise to modern-day jawed vertebrates, including bony fish and humans.

The fossil, named Tethymyxine tapirostrum,is a 12-inch long fish embedded in a slab of Cretaceous period limestone from Lebanon. It fills a 100-million-year gap in the fossil record and shows that hagfish are more closely related to the blood-sucking lamprey than to other fishes. This means that both hagfish and lampreys evolved their eel-like body shape and strange feeding systems after they branched off from the rest of the vertebrate line of ancestry about 500 million years ago.

 

 

Read more at: https://phys.org/new...ebrate.html#jCp

[Sciencerocks]

Prehistoric shark with 'spaceship-shaped' teeth discovered in ancient riverbed
 

'The more we discover about the Cretaceous period just before the non-bird dinosaurs went extinct, the more fantastic that world becomes'

The remains of a freshwater shark that swam the rivers of South Dakota 67 million years ago have been unearthed by scientists.

Tiny teeth sifted from over two tonnes of prehistoric earth revealed a bottom-dwelling creature similar to some modern-day carpet sharks that ambush their prey from the ocean floor.

It was these teeth – which reminded the team of the spaceships from the 1980s video game Galaga – that gave the creature its name, Galagadon nordquistae.

The shark was discovered in the ancient sediment found alongside Sue the Tyrannosaurus rex, a famous specimen held at the Field Museum of Natural History in Chicago.

 

https://www.independ...obox=1548101570

[Sciencerocks]

Iguana-sized dinosaur cousin discovered in Antarctica

January 31, 2019, Field Museum

 

250 million years ago, it was covered in forests and rivers, and the temperature rarely dipped below freezing. It was also home to diverse wildlife, including early relatives of the dinosaurs. Scientists have just discovered the newest member of that family—an iguana-sized reptile whose name means "Antarctic king."

 

"This new animal was an archosaur, an early relative of crocodiles and dinosaurs," says Brandon Peecook, a Field Museum researcher and lead author of a paper in the Journal of Vertebrate Paleontology describing the new species. "On its own, it just looks a little like a lizard, but evolutionarily, it's one of the first members of that big group. It tells us how dinosaurs and their closest relatives evolved and spread."

 

 

Read more at: https://phys.org/new...rctica.html#jCp