Velociraptors Hunting Like Birds

Not Exactly Rocket Science has an interesting article on the possible hunting patterns of some dinosaurs that had claws resembling the talons of big birds of prey. They may have used their claws to pin down their prey, as opposed to hacking and slashing. The article is definitely worth reading in its entirety, so go check it out if you can, but otherwise here are the highlights:

In [paleontologist Denver Fowler’s] vision, which he calls the “ripper” model, Deinonychus killed small and medium-sized prey in a similar style to a hawk or eagle dispatching on a rabbit. Deinonychus leapt onto its target and pinned it down with its full body weight. The large sickle-shaped claws dug into its victim, gripping tightly to prevent it from escaping. Then, Deinonychus leant down and tore into it with its jaws. The killer claws were neither knives nor climbing hooks; they were more like anchors.

It’s a simple idea, but a potentially important one, for it casts Deinonychus’s entire body into a new light. Fowler thinks that it flapped its large feathered arms to keep its balance while killing a struggling victim. And its feet, which were adapted for grasping prey, would have given its descendants the right shape for perching on branches. Fowler says, “It really helps to make sense of the weird anatomy of these little carnivorous dinosaurs.” …

This idea of Deinonychus sitting on top of small prey seems at odds with classic picture of this predator working in packs to bring down larger quarry. But again, modern birds show how the same grasping motions might have worked against big targets. Golden eagles can kill reindeer. They dig their talons deep into their victim’s back, holding on while the struggling reindeer widens its own wounds. Deinonychus might have used the same strategy to kill larger prey.

Tom Holtz Jr, who studies predatory dinosaurs, says, “Prey-riding is also common in the Galapagos hawk – there’s classic footage of them taking down marine iguanas much bigger than they are. They pin them down, and flap away as the iguanas take them for a ride.” Philip Currie from the University of Alberta also mentions the famous Mongolian “fighting dinosaurs” – a Velociraptor found in pitched battle with a Protoceratops. “It confirms that dromaeosaurids were seeking prey animals of their own approximate body size.” …

If Fowler is right, his model has important implications for the evolution of flight. The dromaeosaurids would have been very nearly ready for life in the trees. Their grasping feet, with opposable toes, could easily have adapted to grip branches as well as prey. Their flapping arms, used to balance themselves, could have adapted to help them fly. These animals were positively pre-adapted for life in the trees. Perhaps the graceful wings and perching feet of a blue tit got their start with bloody murder on the ground.

Proposing such a strong connection between dinosaurs and modern birds is pretty interesting; it’s useful to see how everything is related. Keep in mind though that at this point, this is only one person’s theory. 


Archaeopteryx and On Classifying Species

There’s a fantastic article at 10,000 Birds about the classification of Archaeopteryx, usually considered the first species of bird to emerge from dinosaurs, and more generally how biologists figure out how to classify ancient species. It’s a pretty great and easy-to-read insight into how to figure out the evolutionary tree that we often take for granted. Check it out!

A New Dinosaur Related to the Triceratops

A new dinosaur species has been announced, a whopping 95 years after the discovery of its fossil. It’s called Spinops sternbergorum (“Sternberg’s spine-face”, after the Sternberg father and son team who discovered the fossil).

A recreation of Spinops via ScienceDaily, copyright Dmitry Bogdanov.

From ScienceDaily:

Spinops was a plant-eater that weighed around two tons when alive, a smaller cousin of Triceratops. A single large horn projected from the top of the nose, and a bony neck frill sported at least two long, backward-projecting spikes as well as two forward-curving hooks. These unique structures distinguish Spinops from related horned dinosaurs…

Parts of the skulls of at least two Spinops were discovered in 1916 by Charles H. and Levi Sternberg, a father-and-son fossil collecting team. The Sternbergs recognized that their find represented a new species and sent the fossils to The Natural History Museum (London). However, the fossils were deemed too scrappy for exhibit, and consequently were shelved for decades. It wasn’t until Farke and colleagues recognized the importance of the fossil that the bones were finally cleaned for study.

I don’t really understand how that happens. How do you discover a new species and then just… let it lie? This field of science definitely seems different than what I’m used to. In any case, I’m glad the discoverers eventually got the credit they deserved.

Incredible Dinosaur Nest Photos

National Geographic has a slideshow of photos of the baby-dino-filled protoceratops nest uncovered recently, and they are unbelievable. Definitely not like anything I’ve ever seen.

To summarize from the slideshow, dinosaur child-rearing habits have been a bit of a mystery; it’s rare for animals to have a large number of offspring and stick around to care for them all, but this nest shows evidence of 15 young protoceratops, suggesting again that dinosaur families are not quite comparable to anything else we’re familiar with. These particular dinos may have all died simultaneously when buried during a sandstorm, since all of the fossils are pointing in a particular direction, presumably away from the wind. 

Photograph via Khishigjav Tsogtbaatar, Mongolian Academy of Sciences, via National Geographic

“Oldest Artist’s Workshop in the World Discovered”

Archaeologists have discovered materials for mixing paint from 100,000 years ago, in a cave in South Africa. Keep in mind that homo sapiens only originated as an anatomically distinct species 200,000 years ago; this means that roughly halfway between the first homo sapiens and the present day, there were already painters. That’s pretty crazy.

From New Scientist:

The purpose of the paint is unknown, but the researchers who discovered the workshop at the Blombos cave on South Africa’s southern coast (see photo) think it was most likely applied to skin for decoration or ritual, or perhaps even as an insect repellent.

Inside the cave, Christopher Henshilwood of the University of the Witwatersrand in Johannesburg, South Africa, and his team found tools and two abalone shells (see photos) that were used for mixing and storing the paint. Alongside one of them were quartzite stones used to hammer and grind ochre to a powder, and animal bones used to stir the powder with other materials, which included bone, charcoal, quartz fragments and other stones.

They also discovered evidence that some of the bones had been heated, probably to melt fat from the marrow that would have then bound the minerals. “There were also quartzite fragments to cement it, mixed with a liquid, probably urine,” says Henshilwood.

The whole lot survived together in one place because after the cave was abandoned it filled with wind-blown sand, sealing the cache as a “time capsule”, says Henshilwood.

Whatever our ancestors did with their paint, the simple fact that they were mixing minerals to prepare it 100,000 years ago is in itself a major discovery, and tells us something about our ancestors’ cognitive abilities at the time.

For instance, Henshilwood points out that this is the first known use of containers from that time. What’s more, the artists would have had to collect ochre and other materials with the specific purpose of making paint in mind – a sign that they were planners – and needed a “basic knowledge of chemistry”.

The nearest known source of ochre, he says, is at least 20 kilometres away from the cave, so the find demonstrates that Homo sapiens was capable of this high degree of organisation and planning only 50,000 to 100,000 years after the species emerged.

It’s pretty interesting to think of very ancient humans doing things that we think of as quintessentially human. If they could find evidence of painting from before the emergence of homo sapiens, that could be quite a shock to people who consider art a defining characteristic of our species (not that “art” or “species” are well defined anyway). 

I wish I had the knowledge to actually evaluate findings like this. On its surface it looks like a whole lot of conjecture, but I’m sure they have their ways of backing it up. 

Possibly Most Complete Fossil Ever Found

Via New Scientist: A theropod in southern Germany has been found with 98% of its skeleton preserved, possibly the most intact fossil ever discovered. This fossil doesn’t leave too much to the imagination:

Died singing

3D Imaging to Document Dinosaur Tracks

LiveScience has an article for us about the technology researchers are using to record fossilized dinosaur tracks – scanning lasers that collect data making it possible to reconstruct a 3D image of the tracks. Getting good images of the fossilized tracks is important because they’ll erode away after they’re uncovered.  

With the help of cutting-edge technology, researchers in Arkansas are unveiling new information about the dinosaurs that existed there 120 million years ago.

What looked like giant potholes in the middle of bedrock terrain in southwest Arkansas has been uncovered as fossilized dinosaur tracks. Now thanks to high-tech light scanner technology, scientists from the University of Arkansas are learning more about the biomechanics and behaviors of the extinct species that once occupied the area by taking 3-D images to record the tracks….

To map the area, Williamson attached a Z+F Imager 5006i scanner, which emits a constant beam of laser light, to a cherry picker. The device then swept across the landscape to measure and record data up to 500,000 points for each second. [Read: 10 Inventions That Were Ahead of Their Time]

The second unit, used to record an overview of the site from above, is a time-of-flight scanner called Leica ScanStation C10. It incorporates discrete pulses of laser light at a rate of 50,000 for each second, recording a point for each in space. This allows researchers to study a three-dimensional “point cloud” representing the tracks.

With these tech tools, the researchers can view a highly accurate map of the site’s dinosaur tracks and take detailed measurements of the height, width and depth of individual tracks, as well as measurements of the trackways. Not only does the technology take precise measurements of the entire area with easy and speed, it also captures minor details of the tracks…

The team looks at where the tracks are located in relation to each other: “Some would be in groups and others would be by themselves. Taking these scans helps uncover more information about what the dinosaurs were doing, whether they were chasing or hunting or just walking along,” Williamson added…

In addition, the tracks help scientists learn information about the frequency of rain and amount of evaporation that once affected the site.

“The air temperature was hot. The water was shallow and very salty,” Boss noted. “Picture an environment much like that of the shores of the Persian Gulf today. It was a harsh environment. We’re not sure what the animals were doing here, but clearly they were here in some abundance.”

Now we wait 10 years for them to build this into smartphones (or the 2020 equivalent)… 3D recording for all!

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