Paleonews: Dinosaurs Were Mostly Scaly

tyrannosaurus_rexFor over a century, the debate about how what dinosaurs truly looked like has raged. In that time, and owing to a poverty of hard evidence beyond fossilized bones, paleontologists have produced some rather wild theories. Whereas some have stuck to the notion that dinosaurs were scaly, others have suggested everything from flat-skin to fur to feathers. And now, it seems that a clear picture may have emerged.

After surveying all the world’s known fossils of dinosaur skin, a pair of paleontologists says the vast majority of non-avian dinosaurs were scaly-skinned, much like reptiles. While the case for certain species of theropods – that gave rise to modern avians – having feathers remains strong, it now seems that these were the exception and not the rule, as some previously thought.

dinosaur_featheredUp until now, opinion remained divided because of the feather-like skin impressions that were found around the fossilized remains of certain theropods, the dinosaur group that contained the likes of Tyrannosaurus and Velociraptor. By contrast, the ornithischian lineage — i.e. Triceratops, Stegosaurus, Ankylosaurus, etc. — and the huge, long-necked sauropod’s were considered to be scaly.

However, the discovery, beginning in 2002, of a few ornithischians with filament-like structures in their skin. This led to speculation that feather-like structures were an ancestral trait for all dinosaur groups. Keen to know more, palaeontologists Paul Barrett of the Natural History Museum in London and David Evans of the Royal Ontario Museum in Toronto created a database of all known impressions of dinosaur skin tissues.

paul_barretAfter compiling the data, they then proceeded to identify those that had feathers or feather-like structures, and considered relationships in the dinosaurian family tree. The results, which were revealed back in October at the annual meeting of the Society of Vertebrate Palaeontology, indicate that although some ornithischians had quills or filaments in their skin, the overwhelming majority had scales.

In addition, the survey results suggest that dinosaur feathers, bristles, or fuzz did not arise early enough in the family tree to spread to many non-avian dinosaurs. According to Richard Butler, a paleontologist from the University of Birmingham in the U.K who was not associated with the study, the results are a “valuable reality check” about the appearance of early dinosaurs.

dinosaur_skinEven so, during an interview with Nature News, Butler was quick to points out that the findings are not set in stone:

We don’t have primitive dinosaurs from the late Triassic and early Jurassic periods preserved in the right conditions for us to find skin or feather impressions. This picture could quickly change if we start finding early dinosaurs with feathers on them.

As a result, paleontologist cannot be precisely sure when or how dino-feathers evolved. If they arose further back in the dinosaur family tree, then more dinosaurs are likely have them. And with new discoveries being made all the time, things may once again tip back in favor of the majority of dinosaurs being feathered, furry or fuzzy.

Source: nature.com, popsci.com

Paleonews: Reconstructing what Dinosaurs Looked Like

dinosaur_bonesSince the first discovery of their remains was made, modern humans have struggled to reconstruct how dinosaurs lived, behaved, and even appeared. As simple as it may seem to the rest of us, paleontologists understand that bones alone do not an accurate representation make. And over the years, many theories have been advanced as to what the full, fleshy forms of dinosaurs truly looked like.

And thanks to a find made in Grand Prairie, Alberta last year, one of the richest source of dinosaur bones in the world, scientists are that much closer to getting an accurate picture as to what one candidate – Edmontosaurus regalis – looked like. In short, the find revealed a body part never seen before on any dinosaur –  a soft, fleshy comb on its head, similar to those found on roosters.

edmontosaurus-regalisAccording to Victoria Arbour, a University of Alberta paleontologist who co-authored the scientific paper published Thursday in the journal Current Biology, the comb constituted a “structure that was completely unexpected.” And that it “kind of makes us wonder what other dinosaurs might have had.” The find is also interesting because of the connection it draws to the biology of today’s animals, something which is still considered distinct from prehistoric creatures.

Edmontosaurus are a duck-billed, plant-eating dinosaur that grew to be 12 metres long and was thought to have roamed North America in herds during the late Cretaceous, about 75 and 65 million years ago. It also belonged to a group of dinosaurs known as hadrosaurs, a family of duck-billed herbivores which were the most common dinosaurs on the continent at the time.

edmontosaurusPhil Bell, a paleontologist at the University of New England in Armidale, Australia, was with the Philip J. Currie Dinosaur Museum currently under construction in Grand Prairie, Alta., when he uncovered the fossil last summer with geologist Federico Fanti of the University of Bologna. As the lead author of the paper, Bell claims that the new findings are a major breakthrough in determining the dinosaur’s behavior.

In particular, the existence of the comb adds to evidence that Edmontosaurus was a social animal, as ornaments like combs and crests are typically used for communication among animals such as roosters, especially in relation to competition for females:

[E]quivalent to discovering for the first time that elephants had trunks. These findings dramatically alter our perception of the appearance and behaviour of this well-known dinosaur. We might imagine a pair of  male Edmontosaurus sizing each other up, bellowing, and showing off their head gear to see who was the dominant male and who is in charge of the herd.

dinosaur_fossilsAnd of course, this find demonstrates many of the limitations imposed on paleontologist, as fossils typically only preserve the bones of an animal and not fleshy structures. But in rare cases, fossils are found that are described as “mummified”, where bones are in the same positions relative to each other that they would have been in life, with impressions of the skin preserved on top.

According to Arbour, it’s not clear what conditions lead the preservation of skin impressions, but it likely involves the animals dying in a flood and being quickly buried by sand or mud. She added that even when skin impressions are preserved, they are often only visible in certain lighting or when the rock breaks a certain way, which may be why combs hadn’t been noticed on earlier “mummified” Edmontosaurus fossils.

dinosaur_skinimpressionsWhile earlier hadrosaurs had bony crests, researchers thought the crest had been completely lost in Edmontosaurus. The new discovery suggests that, in fact, the dinosaurs’ crests had changed, but remained an important feature. Bell said it also suggests that similar structures may have been missed in other dinosaurs:

There’s no reason that other strange fleshy structures couldn’t have been present on a whole range of other dinosaurs, including T. rex or Triceratops.

So really, this single find could have far-reaching implications for the field of paleontology. And with time, more discoveries, and additional refinements to the excavation process, we might just get a full and complete picture of what life really and truly looked like on Earth millions of years ago.

Source: cbc.ca

Dinosaur Eggs Found With Embryos Still Inside

Dinosaur-eggsThis past week, a Canadian group of paleontologists from the University of Toronto announced a rather amazing find. In the course of examining a large fossil bed in China’s Yunnan province, they discovered a series of fossilized dinosaur eggs that are apparently the oldest ever found. But it’s gets even better. Within the nest, they learned that many of these eggs had been crushed, and the remains of several dinosaur embryos perfectly preserved.

The eggs belong to the Late Jurassic, a geologic period that occurred roughly 190 million years ago. It was during this time that a group of huge, long-necked plant-eating dinosaurs called Lufengosaurus gathered together at the site in China’s Yunnan province to lay clutches of softball-sized eggs. It is here that Robert Reisz, leader of the paleontologist group, and his colleagues found the rare preserved remains.

UofT_reiszThese included the crushed eggshells —the oldest dinosaur eggshells ever found — and 200 tiny bones from at least 20 Lufengosaurus embryos, including some that amazingly still appeared to have some protein attached to them. Reisz said it appears that Lufengosaurus chose a nesting site close to a river and some years the nesting site flooded, smothering the embryos. At the time of the dinosaurs, the area had a tropical climate and was likely prone to monsoons during the wet season.

In an interview, Reisz claimed that “[the] eggs were caught at different stages of development. That’s what makes this project really exciting.” It’s exciting because it allows paleontologists to examine how dinosaurs grew while still in the earliest phase of their development. And already, the returns on this discovery are proving very intriguing.

UofT_fossilsFor example, by examining at the thigh bones of embryos of different ages, Reisz and his researchers found evidence that this particular species moved around inside their eggs as birds do, and similar to the way developing mammals move around inside the womb. This is the first time that phenomenon has been documented in a fossil animal, but the real breakthrough was the detection  of the chemical fingerprint of a protein inside the bones.

Ordinarily, paleontologist do not expect to find any protein samples in fossils dating back this far. However, the Taiwanese members of the research team were insistent that they look for proteins using synchrotron radiation and an infrared spectrometer, which looks for the telltale chemical signatures caused by specific molecules absorbing characteristic colours of light. Given what it turned up, Reisz was happy they did!

t-rexThe protein that was detected is believed likely to be collagen, a common protein found in connective tissues such as bones and tendons. Once again, the significance of this is in how it will allow future generations of researchers to examine the links between today’s species and those from previous eras. According to Reisz: “If this is collagen, then the potential for extracting collagen and comparing to those of living animals really opens a new area of research.”

And who knows? If the protein sample proves to be in good enough shape, this particular species of dinosaur might actually find itself being added to the list for de-extinction, right alongside Aurochs, Wooly Mammoths, Do Do birds, and Sabretooth Tigers. Hmm… I guess Jurassic Park isn’t as farfetched as previously thought. In fact, it could one of many geological era-themed parks put all over the world. Personally, I’d hate to be the zoning board that has to find places to host them!

Source: cbc.ca/news

Candidates for De-Extinction

Woolly Mammoth Replica in Museum ExhibitIt’s no secret that humanity’s success on this planet we call Earth has come at a high cost. Since our ancestors began migrating out of Africa some 70,000 years ago, their passage and settlement have left marks on the natural environment and its species. In short, our ability to grow has always meant extinction for other species, be they other forms of high-order primates (such as Neanderthals) or animals hunted for their pelts and meat (such as wooly mammoths).

In fact, the Neolithic Revolution, which began some 15,000 years ago with the adoption of farming, was believed to have been motivated by the mass extinction of animals that were once hunted by our ancestors. And since that time, countless more species have been pushed to the brink or killed off entirely by our ever-expanding, consuming, and polluting ways. However, recent innovations in biology and bio-medicine might just be able to reverse this trend.

??????????????????????????????????????????????????????????????????????????????????Last Friday, at a at a National Geographic-sponsored TEDx conference, scientists met in Washington, D.C. to discuss which animals we should bring back from extinction, as well as the means and ethics involved in doing so. They called it “de-extinction”, and considered which species they would consider restoring to existence. The conference resulted in a list of 24 species that were selected for restoration, as well as some guidelines for the selection process.

Those chosen were based on the following criteria and future selections will be determined the same way:

  1. Are the species desirable — do they hold an important ecological function or are they beloved by humans?
  2. Are the species practical choices — do we have access to tissue that could give us good quality DNA samples or germ cells to reproduce the species?
  3. And are they able to be reintroduced to the wild — are the habitats in which they live available and do we know why they went extinct in the first place?

As you might imagine, dinosaurs didn’t make the cut. In addition to no longer serving and important ecological function, the habitats they once had access to are long gone (Earth’s climate and ecology have changed drastically since the Cretaceous Period), and most importantly, we no longer have access to their DNA.

TEDxDeExtinctionYes, despite what Michael Crichton told us, the DNA of dinosaur fossils is so far degraded that something like Jurassic Park would never be possible. And of course, despite being beloved by humans, they aren’t exactly safe customers to have around! But rest assured, the list of candidates is still very long.

Of the 24 species selected, the majority were families of birds which were pushed to extinction due to hunting, deforestation, urban sprawl, pollution, and loss of habitat. In addition, the famous Auroch, a species of cattle that is commemorated in myth but which actually existed until 1627. And then there’s the equally famous DoDo bird, the fearless bird which was rendered extinct by Portuguese settlers in its native Mauritius.

woolly-mammoth1And then there’s the venerable Wooly Mammoth, the great shaggy member of the Elephantidae family which went extinct some 4000 years ago. Not only is this animals demise directly associated with humanity’s ascendance to the top of the food chain, it is something which may now be entirely reversible. Thanks to frozen, preserved carcasses of Mammoths, which are still found in the north to this day, scientists have access to well-preserved strands of their DNA.

And as already noted, the issue of cost, ethics and desirability featured pretty prominently in the conference. For starters, those present had to consider whether or not it would be a good idea to bring animals back from the brink seeing as how it was human agency that led to their extinction in the first place. Is the world any better off than it was hundreds or even thousands of years ago? Would these animals find new purchase, or just end up dying off again?

sabre-tooth-tiger-_1117360cSecond, there was the question of housing them and reintroducing them into the wild. Not only is it a question of them being able to find habitats again, it’s a question of whether or not we can ensure the kind of transition that would be needed. Sure, we’d all love to see Sabre-Tooth tigers alive and well again, but its not like we can just clone them and send them back out into the wild. Who’s to say how their reintroduction will impact species that are currently roaming about in the wild?

And of course, there was the consideration of what all this tampering amounts to. Given that human agency is responsible for all this loss of life, would resurrecting them simply be more of the same? Would we be, in effect, playing God and tampering with forces best left to nature? All good questions, and they force us to consider an alternative proposition.

Perhaps what would be best for the natural world and its remaining species would be for us to stop behaving so irresponsibly. Perhaps we should focus on sustainable living, cleaning up pollution, ending climate change, and getting our own population under control before we start trying to repopulate other species. Still, it is an intriguing possibility, and provides some reassurance that no matter how much damage we end up doing, that we might be able to undo some after the fact. Perhaps we just need to wait…

Too bad about Jurassic Park though. In the course of everything else discussed at this TED conference, I’m sure that the announcement that dinosaurs were as good as gone shattered the dreams of many an eccentric billionaire!

t-rex

Sources: businessinsider.com, nationalgeographic.com

Eyes in the Sky: The Future of Asteroid Defense

asteroid_beltWith the recent passage of DA14 – an asteroid half as large as a football field and packing the power of a hydrogen bomb – and the rather explosive display that occurred above Russian skies, it’s little wonder then why NASA and other space agencies are publicizing various existing and proposed solutions to our “asteroid problem”.

Granted, there really isn’t much of a threat of an asteroid colliding with the Earth in the foreseeable future. And we also know that the meteor that graced the skies over the Urals was unrelated to the DA14 behemoth. But given that an impact could mean an Extinction Level Event, similar to the Cretaceous-Paleogene event that caused the extinction of the dinosaurs, a little planning doesn’t hurt.

neossat-580x317The first in a series of three existing or proposed designs is the NEOSSat – Short for Near-Earth Object Surveillance Satellite – that was built in Canada and was deployed last week on an Indian rocket with six others. In addition to watching space debris in orbit and tracking their movements, it will also be keeping a sharp eye out for asteroids that may swing by Earth in the future.

AIDA_mission_conceptThen there is the ESA’s proposed Asteroid Impact and Deflection Assessment mission (or AIDA), a group of planetary defense satellites that will are designed to collide with an asteroid, then push it off course. And after two years of planning, research teams from the US and Europe have selected the mission’s target – a so called ‘binary asteroid’ named Didymos – that AIDA will intercept when it passes the Earth by a mere 11 million km in 2022.

The third and final proposed solution is something that sounds ripped from the pages of a science fiction novel. Known as the DE-STAR, or Directed Energy Solar Targeting of Asteroids and exploRation, this satellite is essentially a orbiting laser that would be capable of destroying approaching asteroids 10 times larger than the DA14 and at a distance as far away as the Sun.

NASA_destarProposed by two California scientists – UC Santa Barbara physicist and professor Philip M. Lubin, and Gary B. Hughes, a researcher and professor from California Polytechnic State University – the satellite is designed to harness the power of the sun and convert it into a massive phased array of laser beams that can destroy asteroids that pose a potential threat to Earth. At the same time, it will be capable of changing an asteroid’s orbit – deflecting it away from Earth, or into the Sun.

Feel safer? Well, considering that the odds of Earth getting anytime soon are pretty low, and are likely to fall even farther once we get these rock killers destroyed. Once more, it seems that sane planning and sensible solutions are winning out over doomsday predictions. Good for us!

Asteroid Misses Earth, Again!

asteroid_DA14Well it seems that Earth has survived yet another close shave with an asteroid. This time around, the object in question was a celestial body known as DA14, a rock measuring 45 meters (150 feet) in diameter and weighing in at 130,000 metric tons in mass. Discovered last year by astronomers working out of the La Sagra Sky Survey at the Astronomical Observatory of Mallorca, this asteroid performed the closest fly-by of Earth ever observed by astronomers.

Basically, the asteroids passage took it within Earth’s geosynchronous satellite ring, at a paltry distance of 27,000 kilometers (17,000 miles). That may sound like its still pretty far away, but to give you a sense of scale, consider that Earth’s geosynchronous satellite ring, which the asteroid passed within, is located about 35,800 km above the equator. So basically, this asteroid was closer to you than the satellite that feeds your TV set. Scared yet?

asteroid_DA14pathNaturally, NASA was quick to let people know that DA14’s trajectory and orbit about the Sun would bring it no closer to the Earth’s surface than 3.2 Earth radii on February 15, 2013. In a statement released in advance of the asteroid’s passage, they claimed:

“There is very little chance that asteroid 2012 DA14 will impact a satellite or spacecraft. Because the asteroid is approaching from below Earth, it will pass between the outer constellation of satellites located in geosynchronous orbit (22,245 miles/35,800 kilometers) and the large concentration of satellites orbiting much closer to Earth. (The International Space Station, for example, orbits at the close-in altitude of 240 miles/386 kilometers.). There are almost no satellites orbiting at the distance at which the asteroid will pass.”

However, they were sure to warn satellite operators about the passing, providing them with detailed information about the flyby so they could perform whatever corrections they needed to to protect their orbital property. All in all, we should be counting our lucky stars, given the asteroid’s mass and size. Were it to have landed on Earth, it would have been an extinction-level-event the likes of which has not been seen since the age of the dinosaurs.

In related news, NASA was quick to dispel notions that this asteroid was in any way related the recent arrival of the meteor above the Urals in Russia. In a statement issued earlier today, they said the following:

“According to NASA scientists, the trajectory of the Russia meteor was significantly different than the trajectory of the asteroid 2012 DA14, making it a completely unrelated object. Information is still being collected about the Russia meteor and analysis is preliminary at this point. In videos of the meteor, it is seen to pass from left to right in front of the rising sun, which means it was traveling from north to south. Asteroid DA14’s trajectory is in the opposite direction, from south to north.”

Good news! We’re not witnessing the End of Days just yet. Take that Apocalyptics! Don’t you people get tired of being wrong? (fingers crossed!)

Source: IO9.com, NASA.gov, (2)