egg

How bird eggs got their shape

dr. dolittle — Sun, 25 Jun 2017 15:20:57 +0000

How bird eggs got their shape

Image of a variety of bird eggs from Internet Archive Book Images, via Wikimedia Commons

Ever wonder why bird eggs are shaped the way they are and what drives the variations in egg shapes across species? I never really wondered that either until I saw an article in Science that explained a possible reason...then I just HAD to know. Some theories had been proposed suggesting that their shape prevented eggs from rolling out of nests or otherwise sustaining damage, and so on. According to the new study, the shape of a bird's eggs may be related to their ability to fly. Researchers compared how elliptical, spherical and asymmetrical 50,000 eggs from 1400 species were. What they discovered is that eggs from species that are strong fliers were more elliptical or asymmetrical. They proposed that the reproductive tract of these birds may have become more narrow, thus leading to the elongated shape of their eggs. It should be noted that not everyone is convinced by this explanation and variations certainly exist in egg shape even among strong fliers. Although the reason for each species is likely more complex, this study offers another clue into the evolution of egg shapes in birds. I wonder if anyone has done a similar study of eggs from reptiles...

Source:

dr. dolittle Sun, 06/25/2017 - 11:20

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How to grow a bigger heart...

dr. dolittle — Tue, 18 Oct 2016 16:19:40 +0000

How to grow a bigger heart...

...in alligators at least.

Image of alligator eggs and hatchling from National Park Service.

Researchers from the University of Manchester, University of North Texas - Denton, and the Rockefeller Wildlife Refuge - Grand Chenier, Louisiana teamed up to explore the effects of exposure to low oxygen on embryonic American alligators (Alligator mississippiensis). Alligator eggs are often laid in nests where oxygen concentrations can reportedly vary between 11-20% (21% is normal atmospheric levels). This is really important as issues related to embryonic development could continue to affect animals throughout their adult lives as well.

The results of the study were recently published in the American Journal of Physiology - Regulatory, Integrative and Comparative Physiology. The researchers found that embryos exposed to low oxygen were smaller and had larger hearts even into their juvenile years. In addition, the mitochondria of juvenile alligators that had been exposed to low oxygen were more efficient at using oxygen. These adaptations may help the animals adjust well to low oxygen environments.

In contrast, a recent review article written by Patterson and Zhang suggests that human embryos exposed to low oxygen do not fare as well as alligators. While a period of hypoxia is important in normal development, prolonged exposure of embryos to low oxygen can result abnormal heart structure and function. In fact, it is thought that these embryos may be more prone to heart disease as adults.

Sources:
Galli GLJ, Crossley J, Elsey R, Dzialowski EM, Shiels HA, Crossley II DA. Developmental Plasticity of Mitochondrial Function in American Alligators, Alligator mississippiensis. American Journal of Physiology - Regulatory, Integrative and Comparative Physiology. In press. doi:10.1152/ajpregu.00107.2016

Patterson AJ, Zhang L. Hypoxia and fetal heart development. Current Molecular Medicine. 10(7): 653-666, 2010.

dr. dolittle Tue, 10/18/2016 - 12:19

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Cardiovascular disease: Chicken or the egg?

dr. dolittle — Tue, 24 Nov 2015 19:03:39 +0000

Cardiovascular disease: Chicken or the egg?

Image of chicken egg from Wikimedia Commons.

Turns out the egg is an important phase. A new study published this month in American Journal of Physiology - Regulatory, Integrative and Comparative Physiology looked at what happens in the egg when a chicken fetus was exposed to low oxygen (hypoxia) conditions. In mammals, this can occur as a result of maternal hypoxia, preeclampsia as well as anemia in the fetus resulting in less red blood cells that can carry oxygen. Understanding this is important as restricted fetal growth is associated with an increased risk for developing cardiovascular disease as an adult.

During fetal development, the heart grows by increasing cell number. Perinatal development, however, is mainly through increasing the cell size.

The researchers exposed fertilized broiler chicken eggs to either normal oxygen (21% oxygen) or low oxygen (14% oxygen) conditions. Similar to mammals, chicken embryos exposed to hypoxic conditions developed smaller hearts relative to body mass as a result of fewer cells.

Source:

Osterman H, Lindgren I, Lindstrom T, Altimiras J. Chronic hypoxia during development does not trigger pathologic remodeling of the chicken embryonic heart but reduces cardiomyocyte number. American Journal of Physiology Regulatory, Integrative and Comparative Physiology. 309(10):R1204-14, 2015. doi: 10.1152/ajpregu.00499.2014.

dr. dolittle Tue, 11/24/2015 - 14:03

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Life Science

cardiovascular disease

Here you try to evaluate which one have cardiovascular disease. I mean in chicken or the egg and this article is good for everyone because everyone like to use Chicken and egg in our daily routine life. So, this post help to keep in mind some points before use it. master papers

always During fetal development, many times the heart grows by increasing cell number. Perinatal development, however, is mainly through increasing so always get some new. shivaay total collection

always During fetal development, many times the heart grows by increasing cell number. Perinatal development, however, is mainly through increasing so always get some new.
Balachaur

Temperature-based sex determination in turtles

dr. dolittle — Thu, 22 Jan 2015 12:41:40 +0000

Temperature-based sex determination in turtles

Photo of a red-eared slider turtle by Nightryder84.

Dr. Thane Wibbels (University of Alabama at Birmingham) is interested in studying how temperature affects the sex of red-eared slider turtle embryos. For humans, the answer is simple: sex chromosomes. You know, the combination of XX means girl and XY means boy.

Turtles are not that simple. Temperature is a factor in determining whether the embryo will be male or female. If the eggs are incubated at 78.8 degrees F, the hatchlings will all be male. If they are incubated at 87.8 degrees, they will all be female. As I'm sure you've guessed, temperatures in between these points will result in a mixture of female and male hatchlings. This temperature-based sex determination is a reptile trait that is speculated to date as far back as 220 million years ago.

A new study published by Drs. Wibbels and Kayla Bieser (Northland College, Ashland, Wisconsin) in the journal Sexual Development tried to understand this mystery. They examined the expression of 5 genes in turtle eggs exposed to either 78.8 or 87.8 degrees. They discovered that a gene called dmrt1 is the earliest gene to be expressed in males and according to Dr. Wibbels, this gene in particular seems to be involved in male sex determination for all vertebrates. The plan now is to find the "male producing" switch that dmrt1 turns on.

Sources:

University of Alabama press release

dr. dolittle Thu, 01/22/2015 - 07:41

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This kind of sex determination fascinates me so much. I was under the impression that it was unique to crocodiles and alligators but after having read the blog I realise that it is quite a norm in the reptilian family.
Does this kind of sex determination result in there being more of a single sex in one area when compared to another?
u12133214

I have read that red-eared slider turtles can be found in New Mexico, north to Ohio, Illinois, Indiana, West Virginia, Kentucky, Tennessee, Georgia and northern Mexico. If in colder areas more males are born and in warmer temperatures there are more females, do these turtles migrate in any way during mating season so that the different sexes are dispersed evenly?

This information is very interesting. I also did not realize that this type of sex determination extended to turtles. I will definitely go do some more research on this.
I was just wondering if Dimakatso is correct in saying that this type of sex determination is a norm in the reptilian family?

Dimakatso, I was wondering the exactly the same thing about the ratio between males and females in certain areas. I know very little about this topic, so I went and did some research. I picked up one line of thought that made sense to me. The outcome of this type of sex determination is obviously directly linked to how it evolved. Currently the evolution of temperature-dependent sex determination is not understood. One theory is that it evolved due to one sex being more suited to specific areas. An example could be that in a warmer area nesting is more successful, so more females are produced to increase the amount that nest next season. This theory is supported by the fact that one male can mate and impregnate many females. So technically the species does need fewer males than females anyway.

It is common occurrence among animals to regulate the amount of babies and the gender of the babies according to environmental constraints in order to ensure the survival of the species.

This can also be seen in humans. Male sperm cells are more susceptible to heat and those carrying the female gene are not.

This is very interesting. Its amazing to see how animals adapt instinctively to ensure survival.

I have read that rising temperatures are resulting in a larger female population and a smaller male population. It is better to have more female turtles because male turtles can mate each year and females cannot. However, the complete absence of males could be tragic to the species.

Does temperature close to 78.8 degrees F or 87.8 degrees F result in more male or females hatch-lings? Does this mean that if the average temperature of a area is closest to either one of the mentioned temperatures there will be more of a gender which the average temperature is closest to?

14399076

I would have to disagree with the theory mentioned by Sam(15036198). If that theory were to be true then one would expect to see more of one sex than the other. With the passage of time this would result in a decrease in the specie's population and population growth, as it would become increasingly difficult for 2 different sexes to find each other and mate. There would also be increased competition for mating partners which could result in conflict.
u15031617

I would have to disagree with Bennett above with the last part of his statement as for females, reproduction is a very energy intensive and risky venture where for males it is much less so. So females would not have to compete for males, but they would have to accept advances from lower quality males, leading to a degradation of the overall quality of the gene pool, and thus a higher mortality rate. However this will also be countered by increased resources like food and territorial spaces, so general population and productivity increases. So in all, it would largely depend on the rate of one versus the other, as factors like these are not easily identifiable for direct consequences on a population.

I partly agree with Chong, H. As the population increases the competition for food will also increase. Over time this will lead to a different gene pool according to natural selection. This might even change this mechanism of sex determination according to temperature (during the course of evolution).

Behind the Galaxy's Most Famous Nebula

esiegel — Mon, 24 Sep 2012 18:14:10 +0000

Behind the Galaxy's Most Famous Nebula

"The self-same atoms which, chaotically dispersed, made the nebula, now, jammed and temporarily caught in peculiar positions, form our brains; and the 'evolution' of brains, if understood, would be simply the account of how the atoms came to be so caught and jammed." -William James

Up in the heavens, there are planets, stars, and galaxies all clearly visible in the night sky.

Image credit: Dan & Cindy Duriscoe, FDSC, Lowell Obs., USNO.

But those stars weren't always there, and they won't be there forever. The other class of object in the night sky -- the nebulae -- come in two types. On one hand, there are the nebulae that result from the death throes of stars, dying in either a supernova explosion or in a gentler blowing-off of their out layers in a planetary nebula.

Image credit: NASA, ESA, C.R. O'Dell (Vanderbilt University), M. Meixner and P. McCullough (STScI).

This release of around 50% of the mass of the star into interstellar space puts enough hydrogen gas out into space that some day down the road, this gas could get another chance to burn as fuel in the nuclear furnace of stars.

But the other type of nebula -- including the most famous of nebulae -- represents a race to form that immediate next generation of stars.

Image credit: Mike Hankey of http://www.mikesastrophotos.com/.

Of course, this hardly looks like a famous nebula; like practically all nebulae visible through a small telescope, it appears like a faint, fuzzy cloud, with perhaps a red tint to it if you can gather enough light.

Of course, you might recognize this -- far more well-known -- view of this nebula a little bit better.

Image credit: J. Hester & P. Scowen, STScI, ESA, NASA.

These famous gaseous structures -- the Pillars of Creation -- are located at the heart of the Eagle Nebula, and tell part of the story of where new stars in the Universe come from.

Practically every galaxy in the Universe, including our own Milky Way, has significantly more hydrogen gas in it than it has stars, in terms of mass. Most of that gas is diffuse, but in a few locations, the gas has clumped together into large molecular clouds, some of which we can see.

Image credit: NASA and The Hubble Heritage Team (STScI/AURA).

Over time, this cool gas will collapse under its own gravity, contracting into denser and denser regions.

When the temperature of those most dense regions inside rises to the critical value necessary to initiate nuclear fusion, a new star is born, and then the great cosmic race begins in earnest.

Image credit: NASA, ESA, and F. Paresce (INAF-IASF, Bologna, Italy), R. O'Connell (University of Virginia, Charlottesville), and the Wide Field Camera 3 Science Oversight Committee.

From deep inside these clouds of interstellar gas, gravity works to pull every atom in that it can and form more and larger stars. But the stars themselves emit intense, ultraviolet light, evaporating and ionizing the surrounding gas and blowing it out into the interstellar medium.

Eventually, after maybe 10% of the gas has formed objects like stars and planets that cannot be blasted apart by mere radiation, the stars will inevitably win.

Image credit: Sergio Eguivar of Buenos Aires Skies, http://www.baskies.com.ar/.

What gets left behind is a star cluster -- in our galaxy in particular, an open star cluster -- which is where our Sun was born about 4.5 billion years ago.

So when you look up at the night sky and see those faint nebulae, with their reddish hues from the recombination radiation of hot, UV-ionized hydrogen, you are watching the last stages of that great cosmic star-formation race.

Image credit: John Nassr at Stardust Observatory.

So why, then, do the most famous pictures of these nebulae not look red at all, but rather colorized in this multichromatic fashion?

Image credit: T. A. Rector & B. A. Wolpa, NOAO, AURA.

This false coloring is done by taking narrow-line spectroscopy of the nebula in three different bands, with each band sensitive to the light that's emitted from a particular element. Although the light coming from the hydrogen atoms far outstrips the light from all other elements, and is red, it is shown in the above composite in green, while oxygen (in blue) and sodium (in red) are more heavily weighted in order to balance out the false color displayed in the final image.

Image credit: Hubble's Color Toolbox, from http://hubblesite.org/gallery/behind_the_pictures/meaning_of_color/eagl….

On the minus side, the human eye would never see anything like this from looking at any part of the Eagle Nebula.

On the plus side, the false coloration definitely brings out the contrast of the gaseous regions, including the 4-light-year-long Pillars of Creation, and also the even larger Fairy of the Eagle Nebula, both of which are in the final stages of forming new stars inside while they are slowly obliterated from both internal and external ultraviolet radiation.

Image credit: The Hubble Heritage Team, (STScI/AURA), ESA, NASA.

These structures -- known as Evaporating Gaseous Globules or EGGs -- are the locations of the last stars that will form in these great nebular complexes. The race between gravity and photoevaporation is one that will be no contest in every known nebula, with perhaps 90% of the gas failing to make it into a star or planet. When all of the EGGs are gone, it's just a matter of time before the rest of the gas remnants are boiled away by the newly formed stars, until only a brilliant star cluster is left.

Image credit: NASA, ESA, and H. Richer (University of British Columbia).

And the remaining gas will return to the intergalactic medium, waiting for another chance to contract in a molecular cloud and form stars all over again.

That's the secret that lies inside every star forming nebula in our galaxy, including our most famous one. And now you know the secret, too.

esiegel Mon, 09/24/2012 - 14:14

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evaporating gas globule

Fairy of the Eagle Nebula is definitely awesome, and that's why a 24x16 partial print of it hanging in my 'office!'

You young whipper-snappers and your Eagle Pillars! Back in my day, our most famous nebula was just a horse's head - like you find in your bed when you cross the wrong guys - and we had to like it!

A bit more about the colour of nebulae.

They're almost NEVER as red as old pictures with film showed.

Film was more sensitive to the red of Hydrogen Alpha end than the blue-green of Nitrogen/Oxygen III. But most of the light output by such nebulae are in the OIII range, where the film emulsion is experiencing a lack of sensitivity, whilst our eyes have the opposite effect.

Most especially with the Orion Nebula, you can with good skies and 8 or more inch Newtonian get a very very tiny hint of pink in the wings, most pictures you see are aping the colour cast of the original film views.

But visually with an 8" Newtonian you'll see a lot more bluish grey, from the OIII emissions in Orion than any form of red.

The horsehead nebula being dark (it's a dark nebula) against a weak and deep red (where your eye is insensitive) background make it a very difficult view.

Wow, that is an interesting astrophotography fact that I did not know, about the old film and the sensitivity to red.

Thanks for sharing! Other than an amateur astronomy night or two, I've only ever looked through scopes much smaller or much larger than 8"; it's weird to have familiarity with up-to-4" scopes and 18-24" scopes, but nowhere in between!

So are the pillars empty voids where gas has collapsed, surrounded by a sea of gas we can see through? Or is it the opposite, with the pillars being dense with gas, surrounded by mostly open space that has been cleared by the burning stars?

Ethan
You've cleared up some of my ignorance about nebulae including where they are located.

I did not know that the Pillars of Creation which is Part of the Eagle Nebulae was part of the Milky Way Galaxy.

So when I read, "The Eagle Nebula is part of our galaxy.." I had to checked wiki. And what did I find?

Wiki does not mention that the Eagle Nebula is part of the Milky Way Galaxy. The only clue that we have is that its "distance: 7,000 ly ".

I might just have to update wiki to explicitly say that "the Eagle Nebula is located in the Milky Way". But first I need a little more information.

Is the Eagle Nebula located in the center bump, the spiral arms or between the spiral arms or above the disk???

I'll have to update wiki's Milky Way Galaxy page too. I don't think it mentions the Eagle Nebula either.

This is an important little error of omission that makes a big difference to my understanding of astronomy, star life cycle, galaxy dynamics etc..

It took a little searching. I needed to enter both "Milky Way" and "Eagle nebula" to get the answer.

But I found this, "The distances to the M16 Eagle Nebula and the M17 Omega Nebula are not known with precision. There is little doubt that these clouds of star formation lie farther away than the more brilliant Great Orion Nebula, the star-forming nebula that’s visible to the unaided eye in the winter sky. When you look at M16 and M17, you’re gazing at deep-sky wonders in the next spiral arm inward: the Sagittarius arm of the Milky Way galaxy.

The M16 Eagle Nebula lies at an estimated distance of 7,000 to 9,000 light-years, and the M17 Omega Nebula is thought to be around 5,000 light-years away. In contrast, the Orion Nebula resides within the Orion spiral arm (the same spiral arm as our solar system) at some 1,300 light-years distant." EarthSky.org

So I'll rewrite the idea and put it on wiki with anything else you educate me about the proper place of the Eagle Nebula in our Milky Way Galaxy. Hmm, it's been a while since I've put something on wiki (It works though); I'll figure it.

Trey, the dark nebulae are cold nebulae or dust clouds that are not hot enough to be significantly ionised (nebula) or glowing (dust). They are only* seen if they are in front of hot ionised nebulae.

The fishes' mouth in the Orion Nebula is one example, the lines in the triffid nebula another. Only visible beause they aren't glowing as bright as the nebula behind them.

They may or may not be part of the overall gas cloud.

*note: The coalsack nebula visible from the souther hemisphere is visible because it singificantly blocks out almost all stars in quite a large area, so is noticeable.

@ Wow:

How does a modern CCD with Bayer filter compare? I know the Bayer has double the green sub-pixels to account for our eye's sensitivity in that range, but is the underlying CCD biased?

Would an H-a filter let you see the red in Orion visually?

Similarly would it help with the Horsehead? Or is it not an issue of background light washing out the red and rather just the low amounts of red light we aren't sensitive to, so the filter would just represent a net loss?

The beyer mask on any CMOS/CCD digital imager (even I believe the Foveon sensor) requires a low pass filter in front of the CCD to allow the spot of light to spread and the light to illuminate several pixels (else a red star illuminating a blue beyer mask would give no output, and any point image would be monochromaticly red, blue or green). All the monochrome CCDs do the same, but mostly so you can remove moire from the image and similar artifacts .

But apart from that, the CCD behind the mask is identical (except the Foveon sensor which has the pixel actually change sensitivity with wavelength for each layer registering a colour).

Putting a Ha filter would help remove any polluting light from stars, nebula, UFOs or skyglow, but wouldn't make the actual image any better, so you still need a lot of light to collect to make your eye register the image.

But, without that extra (unwanted therefore "noise") light from nearby things, you'll find it easier than without.

Since the light from the horsehead nebula is entirely Ha, there's no loss in the filter (well, maybe 2% loss), and most of the light from Orion is at the ~500nm of OIII, so it WILL be dimmer, and by quite a bit.

The Ha filter is often called the horsehead filter since the horsehead nebula is one of the few strong pure Ha sources amateurs can easily get a look at.

Lastly, on the beyer mask, there is quite a lot of overlap between the red, blue and green channels on a digital colour mask, so your green pixel will still pick up ~20% of the intensity of mainstream blue or red light falling on it. A Ha filtered image will register a tiny bit of green but no blue. However, you can use the blue as your dark image, which is kind of handy...

The filters visually do nothing other than remove extra light you're NOT interested. This helps perceive the image, but doesn't make it much easier.

This may help:

www.stark-labs.com/craig/articles/assets/Debayering_API.pdf

Its not easy to get a google search result about the technical aspects of digital imaging without it being a shedload of images.

Last thing. With a proper astronomical CCD sensor you're looking at up to 90% quantum efficiency (you have a 90% chance of catching EACH PHOTON as a signal) for monochrome peak, a peak of ~65% for a colour astronomical CCD sensor, and ~20% or less for a DSLR or compact/webcam sensor.

Add to that the active cooling (you reduce the noise by half for each 7degrees C of cooling applied), and there is a very big difference.

The sensor on an astronomical CCD will be ~1-2MPix, on a sensor 9mm across for about the same price as a APS-C 12MPix Cannon DSLR (23mm across).

Compact (including the bigger fixed-lens SLR-type) will range from a 6mm 8MPix image to 18mm 20MPix. The light gathered per pixel here is obviously even worse.

"The filters visually do nothing other than remove extra light you’re NOT interested."

Indeed, which is why I actually use my UHC filter much more frequently at my house than when I'm at an actual dark sky location. Orion, for example, looks better without the filter when it's dark.

I just thought maybe it'd be neat to see it red, to go "yep, there's H-alpha in there". But doesn't sound worth it for that and making one other nebula slightly easier to see.

Thanks for the info.

Aye, narrow band filters are often something bought for a group and shared round.

Mind you, you can get pretty close with a Wratten 29A (IIRC, it's the deepest red, often used in gel film in darkrooms) filter. It is a bandpass filter that goes pretty much from ~670nm to way past 750nm and as far as your eyes are concerned, pretty much the same.

Another thing about electronic cameras' sensitivity to red light is that the sensors themselves are sensitive enough to infrared light that there's generally a filter between the lens and sensor to eliminate most of that infrared, and it generally takes some of the red with it. When getting a good DSLR for astrophotography, the serious astrophotographer will usually remove that filter (or have it removed); for a while, one of the Canons was even available in a special astrophotography version that came without that filter. (I think it was either a 5 or a 20?)

OK, just checked up on that, and it was the EOS 20Da (the "a" for "astrophotography", and it's otherwise mostly like a EOS 20D), from 2005 to 2006. What I didn't know is that they have recently come out with a successor, finally, the EOS 60Da. Guess which camera it's otherwise like?

Classic Polaroids? No, no, wait, I'll get it...

The EOSDa doesn't really help that much. You get maybe a stop or so benefit, but that's not actually that much of a benefit with digital. Just take two shots, line 'em up and take the mean.

Spectacular nature work imagine by mankind

Sanajeh, the snake the ate baby dinosaurs

edyong — Mon, 01 Mar 2010 19:00:03 +0000

Sanajeh, the snake the ate baby dinosaurs

Snakes have been around for nearly 100 million years and scientists have found many fossils of extinct species. But this astonishing specimen is different. This serpent is Sanajeh indicus. It is sitting in a dinosaur nest and its coils surround three eggs and the body of a hatchling.

There are many reasons to think that this prehistoric tableau represented a predator caught in the act of hunting, rather than a mash-up of unconnected players thrown together by chance. The snake is perfectly posed, with its head resting atop a coil and its body encircling a crushed egg. All the pieces are very well preserved and very little of the snake, the dinosaur or the crushed egg have been deformed. All of this suggests that the animals were caught unawares and quickly buried in sediment.

The hatchling in question is a baby sauropod part of the dinosaur lineage that included the largest land animals of all time. It was probably a titanosaur, and being in India, that narrows things down to two known species - Isisaurus and Jainosaurus. The adults were formidable animals, 20-25 metres in length and protected by bony armour running down their backs. But even the largest dinosaurs must have hatched out of a small egg, and at that point, they were vulnerable. The hatchling that Sanajeh was about to dispatch was just 50 centimetres long, while the snake itself was measured 3.5 metres.

Despite this size discrepancy, the hatchling would still have been a substantial mouthful. Most modern snakes wouldn't have any problem with that. Their lower jaws can unhinge to give them a massive gape and their flexible skulls are made of bones that can move against each other.

Sanajeh was halfway towards developing these specialisations. It didn't have the fixed skulls and narrow gapes of the most primitive of modern snakes, nor could its maw open quite as wide as today's record-breakers. Nonetheless, it could certainly swallow a sauropod infant and that ability earned Sanajeh inidcus its name. The words are Sanskrit for "ancient gape from the Indus".

Sanajeh dates back to 67 million years ago but even after its bones were unearthed, it still took 26 years to reach the public eye. Dhananjay Mohabey first dug up the incredible specimen in 1984, near the Indian village of Dholi Dungri. He correctly identified the dinosaur baby and the remains of its egg but thought nothing more of it. The specimen's true nature only became clear 17 years later, when Jeffrey A. Wilson from the University of Michigan visited Mohabey and re-examined the specimen. To his amazement, he spotted the distinctive backbones of a serpent, intertwined around the baby.

Peering through the Geological Society of India's archives, the duo found a second block that had been collected at the same time but never been described. It snapped onto the first like pieces of a jigsaw, completing the loop of the snake's coils around the crushed dinosaur egg. Even then, it took years of negotiations with the Government of India Ministry of Mines before Sanajeh could be taken to Michigan for careful preparation and study, and before the Mohabey and Wilson could return to the original dig site to find more specimens.

They did eventually find two Sanajeh individuals at the same site, both associated with sauropod clutches. This suggests that their original drama wasn't a one-off production. At least in this area, this snake seems to have made a habit of feasting on would-be giants.

Perhaps the snakes are drawn to the nests by the presence of newly-hatched infants. After all, it's one of the few moments when they would actually dwarf their prey, a size advantage that would disappear within months. Alternatively, Wilson suggests that Sanajeh may even have deliberately crushed the egg to free the meal within. Today, the Mexican burrowing snake (Loxocemus bicolor) certainly sets a precedent for this - it breaks the eggs of Olive Ridley turtles before eating the contents.

Reference: Wilson, J., Mohabey, D., Peters, S., & Head, J. (2010). Predation upon Hatchling Dinosaurs by a New Snake from the Late Cretaceous of India PLoS Biology, 8 (3) DOI: 10.1371/journal.pbio.1000322

Model by Tyler Keillor and photographed by Ximena Erickson

More on snakes:

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edyong Mon, 03/01/2010 - 14:00

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I wonder what event might have occurred that would have caused them to be frozen in time this way. Amazing! Thanks Ed for reporting on it.

This link should work; the paper is up, even of the DOI isn't.

Maybe a flash flood or a land slide.

Just want to say, that is so friggin cool. I love it when nature hits the pause button for us until we we're here to see the show.

So, they found another S. indicus buried in the same landslide? Maybe the real news here is that they hunted in packs.

Impressive but this snake can't compare to a Titanaboa who was way bigger and scarier.

Naw, this is all wrong, Ed! This is evolution in action: clearly the snake has given birth to the dinos...!

A snake eatin' an egg. Whaddya know!

An old man told me the following story when I was a kid. He swore that it was true:

A black rat snake crawled into a manger in the barn, where a hen had made a nest and laid a clutch of eggs, swallowed an egg, then proceeded to crawl thru a knothole in a partition between stalls, where it found another hen's nest and swallowed a second egg. The bulges were on either side of the partition so the snake could proceed neither forward or back out. They found the snake stuck there like that. Truth or fiction?

Isisaurus and Jainosaurus are both genera, not species. In addition, I find it hard to believe that titanosaur diversity has been sufficiently explored to make an identification based on geography. In the actual article, the authors only identify the eggs; rather than the sauropod hatchling itself.

An 60,000-year old artistic movement recorded in ostrich egg shells

edyong — Mon, 01 Mar 2010 14:00:18 +0000

An 60,000-year old artistic movement recorded in ostrich egg shells

Souvenir shops in South Africa are full of lamps made out of ostrich eggs. The eggs are so big and strong that you can carve and cut intricate designs into their shells. The egg's contents are emptied through a hole and a bulb can be inserted instead, casting pretty shadows on walls and ceilings. The results are a big draw for modern tourists, but ostrich eggs have a long history of being used as art in South Africa. The latest finds show that people were carvings symbolic patterns into these eggs as early as 60,000 years ago.

Pierre-Jean Texier from the University of Bordeaux discovered a set of 270 eggshell fragments from Howieson Poort Shelter, a South African cave that has been a rich source of archaeological finds. Judging by their patterns, the fragments must have come from at least 25 separate eggs, although probably many more.

Texier says that the sheer number is "exceptional in prehistory". Their unprecedented diversity and etched patterns provide some of the best evidence yet for a prehistoric artistic tradition. While previous digs have thrown up piecemeal examples of symbolic art, Texier's finds allow him to compare patterns across individual pieces, to get a feel of the entire movement, rather than the work of an individual.

As you might expect, the millennia haven't been too kind to the shells but even so, their etchings are still well preserved and Texier even managed to fit some of the pieces together. Despite the variety of fragments, their patterns fall into a very limited set of motifs produced in the same way - a hatched band like a railway track, parallel(ish) lines, intersecting lines, and cross-hatching. It's possible that, once assembled, these elements would have combined into a more complex artistic whole but Texier notes that he has never found a piece with more than one motif on it.

Much like any other artistic movement, the shell designs had rules that everyone abided by, but also room for some stylistic latitude. There were four main styles but each had some wiggle room in their execution. The railway track, for example, had lines of different lengths and intersection angles. While some fragments had just one track, others had two or three.

These traditions also seem to have risen into fashion and fallen out of them again. The railway track motif only turns up in the lower parts of the cave and not in eggshells from the upper reaches. Go further up, and it's the parallel lines motif that dominates. To Texier, the shell motifs are evidence that these prehistoric humans were more than capable of symbolic thought, of using patterns to transform ordinary items into specific and unique ones.

Today, hunter-gatherers in the Kalahari still collect ostrich eggs, for food, as beads, or as water containers. They puncture a small hole in the top of the egg, empty their contents and fill them with water. Texier says, "Some Bushmen groups, like the !Kung, use a graphic and schematic tradition to communicate collective identities as well as individual ones." He thinks that the prehistoric hunter-gatherers may have used the eggs for a similar purpose. Their engravings may have been used to intentionally mark ostrich eggshell containers and some of the fragments show signs of forced entry, typical of modern egg-based water containers. To Texier, they were "elements of a collective and complex social life", signs of a modern human intelligence operating tens of thousands of years ago.

Christopher Henshilwood, another anthropologist working in South Africa, was also impressed. "Based on sheer numbers the evidence for deliberate decoration and symbol use is compelling." He adds, "Perhaps the greatest challenge still is in explaining why the tradition of engraving appears to... appear, disappear and then reappear at different times and places."

Several years ago, Henshilwood found a different piece of abstract art at another South Africa cave called Blombos. It was a slab of ochre, also covered in geometric carvings and dating back to 70,000 years ago. "Is there really a connection betweeen the engraving traditions at 100 ka, 75 ka, 60 ka and those in the Later Stone Age?" he asks. "And why are engraved ostrich eggshells and ochre only found at some Middle Stone Age sites and not others?"

Reference: Texier, P., Porraz, G., Parkington, J., Rigaud, J., Poggenpoel, C., Miller, C., Tribolo, C., Cartwright, C., Coudenneau, A., Klein, R., Steele, T., & Verna, C. (2010). A Howiesons Poort tradition of engraving ostrich eggshell containers dated to 60,000 years ago at Diepkloof Rock Shelter, South Africa Proceedings of the National Academy of Sciences DOI: 10.1073/pnas.0913047107

More on art and archaeology: Prehistoric carving is oldest known figurative art

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edyong Mon, 03/01/2010 - 09:00

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Ok, so I get that they carved the ostrich egg shells, and the stylistic changes, and all that, and how important it is for our understanding of our culture... but I think you are missing the far more mind-boggling question:

Where did they plug in the lampcords?

I just love to imagine those artists of 60,000 years ago. How much have human beings really changed since then? It's such a short time really.

Could these eggs and their "decorations" also predate the basic early writing on amphorae used to store grain and identify its owners in the fertile crescent of the Middle East? Is it pure art or did it serve a functional purpose?

Could these eggs and their "decorations" also predate the basic early writing on amphorae used to store grain and identify its owners in the fertile crescent of the Middle East?

I think the earliest records of grain storage of any sort only went back to about 11,000 BCE - much, much younger than this ostrich egg art.

Not writing, rudimentary counting, another type of record akin to 'counting sticks', and the sacred red ochre slab - Hunter-gather clan portable records.

Doubt it's simple abstract artwork. Early humans were acting with intent, driven by harsh conditions after a long period of paleoclimate chaos. Ancient South Africans were dispersing, migrating northward. Climate change was afoot, cooling and drying with the onset of glaciation.

http://www.esd.ornl.gov/projects/qen/nercAFRICA.html

>How much have human beings really changed since then? It's such a short time really.

Well, it's a short time-frame....if you are a rock.

On potential for ancient uses for these shells: probably water storage, but maybe for seed and nut transport and storage as well.

Before grain cultivation 7-10K years ago, wild grains may have been collected, stored and crudely prepared as a mash, but they wouldn't have been a dietary rarity because ancient grains heads were low yield and had limited very geographical range. Moreover, ancient human lacked the technical innovations necessary for large-scale grain harvesting: threshing, winnowing, and grinding. Grinding broke down grain cells walls and liberated nutrients that would be otherwise unaccessible to gut mechanical or chemical digestion.

Domestication of grains induced dramatic changes in diet-induced cellular metabolism in humans. Just as the ancient practice of cooking meat and ground roots in simple hearths have been hypothesized to have altered brain size and anatomic features at a much earlier time (long before 60 KYA), the addition of cooked domesticated grains to the human diet dramatically changed gut microbiota and energy supply, with concurrent shift in secretory and immune function, by introducing an ample supply of fast-acting energy in short-chain fatty acids and starch.

These caloric benefits came with a cost: anti-nutrients, grain components like phytates, lectins (wheat gluten) and alkylrescorcinols (inflammatory agents).

The timing of animal and grain domestication with sedentary (non-migrating) lifestyle in permanent settlements, and attendant population and technological growth is critical for understanding emergence of many human pathogens and chronic diseases.

It's a very, very interesting story. That's what can happen in just 10,000 years time.

A few comments: the site's actually called Diepkloof, and the engrave ostrich eggshell fragment were found in layers attributed to the Howiesons Poort cultural tradition, which is documented in only a few of the site's archaeological layers over a period of ca. 10,000 years. This raises the questions of why these behaviors (both use of ostrich eggs as containers, and their decoration) appear so comparatively fleeting, especially since it's generally argued they represent evidence for the 'modern' behavior critical to H. sapiens success. I discuss some of this here:
http://averyremoteperiodindeed.blogspot.com/2010/03/60000-year-old-deco…

Giant Egg Opens to Reveal....Another Egg Inside!

bleimanb — Fri, 07 Nov 2008 13:52:07 +0000

Giant Egg Opens to Reveal....Another Egg Inside!

Students at Shiga high school in Japan were amazed when a chicken of theirs laid a humungous egg which was 8.1 centimeters high and weighed 158 grams (Sorry for the metric measurements. In Fahrenheit, those numbers translate roughly to 14 feet tall and over 2200 lbs.). They were so amazed that they planned on displaying the monster egg. Someone, however, had the idea to cut back some of the shell to see what was inside and lo and behold, they encountered another, medium sized egg! Assistant principal Toshitaka Minami announced the finding to the school last week.

Who wants a whale meat omelette?

Some are speculating that the new egg may contain an even smaller egg, but I don't believe so. I think it's filled with an even larger egg, larger than the original giant egg that started this whole thing. It's called the circle of life; you should read about it some time.

Shout out to David Lin for sending this along!

bleimanb Fri, 11/07/2008 - 08:52

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egg

chicken

hahahahahahah!!!!!

This had me laughing..... "It's called the circle of life; you should read about it some time."

This is how Russian dolls reproduce.

Wow, chicken reproductive systems must be really stretchy.

Don't you think it's rather wonderful how chickens can make eggs? Quite a masterpiece of packaging!

Cadbury's Creme Eggs need a much larger machine and they don't hatch as little birdies, just as sugary goo.

Go Chickens!

you should check your measurement conversions.. (or was it supposed to be a joke?) Fahrenheit is only a measurement of temperature..and 8.1 cm is not 14 feet and 158 grams is not 2200 lbs.

Hmmm...20 ft tall chick. By my calculations, in Farenheit, you must weigh over 600 kilopounds!

Will we ever find out what was inside the second egg?

This had me laughing..... "It's called the circle of life; you should read about it some time."

Snails versus Slugs (and Friends)!

zooillogix — Thu, 27 Mar 2008 10:14:23 +0000

Snails versus Slugs (and Friends)!

We have brought you the outstanding time lapse photography of Mochimochi Land in the past, but these new works are breathtaking.

No-holds-barred snail on slug rumpus!

"The Great Foot Race!"

Friends below the fold

Reversible chicken and egg. If only life were so easy.

"Beware the Ninjabun...He's covert, sneaky, and hungry!"

"The world's fattest butterfly thinks it might be time for a diet. The flowers agree."

zooillogix Thu, 03/27/2008 - 06:14

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Cute!

Have I converted you over to the dark side of fiber-brain-control? I'll be happy to be your spinning, knitting, and biology buddy!

Kitchen Science: How to Get an Egg into a Bottle (and out Again) Without Breaking Anything

grrlscientist — Mon, 11 Feb 2008 07:59:59 +0000

Kitchen Science: How to Get an Egg into a Bottle (and out Again) Without Breaking Anything

tags: Egg in a bottle, air pressure, streaming video

This is an amusing video demonstration of how to get an egg into a bottle (and then, how to get it out again) without breaking anything -- neither the egg, nor the bottle, nor anything in your parents' kitchen [2:18]

grrlscientist Mon, 02/11/2008 - 02:59

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Very cool. I remember seeing this in early elementary school - maybe even kindergarten. I'm pretty sure I thought at the time that the eggs were raw and still had their shells.

@Carl: -LOL- I had exactly the same thought. Peeled hardboiled egs are easy. Let's see them try it your way!

These lying cheaters are worse than Bush. How can you peel an egg without breaking the shell?

The proper way to do this is to soak a hardboiled egg in vinegar overnight to soften the shell. Then heat the bottle with hot water, pour out the water, and insert the egg. As the steam cools the egg will be sucked in. The burning paper thing is stupid--it gets your egg dirty.

You can peel a hard-boiled egg, Bob. Pay attention.