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aamukherjee A Slice of Entropie -
alchymista Alchymista -
crownedrose Fading Like A Dead Star -
expose-the-light Quarks to Quasars -
ikenbot CWL -
abluegirl A Blue Girl -
perscientiamlibertas A Matter of the Most Pleasant Fraternal Confidence
Oldest Dinosaur Embryos Discovered
By Azadeh Ansari, CNN: Everyone knows dinosaurs were gigantic, but they grew from tiny embryos just like birds do. What were these extinct reptiles like at this early stage of development?
Scientists have found some new clues that could shed light on this age-old mystery.
In a study published Wednesday in the journal Nature, scientists said they have discovered the oldest known collection of fossilized dinosaur embryos.
“In a way, I think we have set a new standard for dinosaur embryology,” said paleontologist Robert Reisz, the lead study author.
Scientists found these dinosaurs grew extremely fast in comparison to present-day living animals and even flexed their muscles while still in the egg.
The bigger the spaces between primary bone cavities, the faster an animal grows. These bone cavities house soft tissue responsible for blood vessel generation.
“In other animals, about 15% to 45% of the embryo bone tissue is made up of these soft tissue cavities; in these dinosaur fossil samples, we found the cavities to make up roughly 60% of the bone tissue,” Reisz said.
crownedroseIn Earth Undergoing a 6th Mass Extinction? - 99.9% of all Past Species Extinct
Of all species that have existed on Earth, 99.9 percent are now extinct. Many of them perished in five cataclysmic events. The classical “Big Five” mass extinctions identified by Raup and Sepkoski are widely agreed upon as some of the most significant: End Ordovician, Late Devonian, End Permian, End Triassic, and End Cretaceous. According to a recent poll, seven out of ten biologists think we are currently in the throes of a sixth mass extinction. Some say it could wipe out as many as 90 percent of all species living today. Other scientists dispute such dire projections.
“If you look at the fossil record, it is just littered with dead bodies from past catastrophes,” observes University of Washington paleontologist Peter Ward. Ward says that only one extinction in Earth’s past was caused by an asteroid impact – the event 65 million years ago that ended the age of the dinosaurs. All the rest, he claims, were caused by global warming.Ward’s study, Under a Green Sky, explores extinctions in Earth’s past and predicts extinctions to come in the future. Ward demonstrates that the ancient past is not just of academic concern. Everyone has heard about how an asteroid did in the dinosaurs, and NASA and other agencies now track Near Earth objects.
Unfortunately, we may not be protecting ourselves against the likeliest cause of our species’ demise. Ward explains how those extinctions happened, and then applies those chilling lessons to the modern day: expect drought, superstorms, poison–belching oceans, mass extinction of much life, and sickly green skies.
The significant points Ward stresses are geologically rapid climate change has been the underlying cause of most great “extinction” events. Those events have been, observed Harvard evolutionary biologist Stephen Gould, major drivers of evolution.
Drastic climate change has not always been gradual; there is solid empirical evidence of catastrophic warming events taking place in centuries, perhaps even decades. The impact of atmospheric warming is most potent in its modification of ocean chemistry and of circulating currents; warming inevitably leads to non-mixing anoxic dead seas.
We are already in the middle, not the beginning, of an anthropogenic global warming, caused by agriculture and deforestation, which began some 10,000 years ago but which is now accelerating exponentially; though the earliest wave of anthropogenic warming has been stabilizing and beneficial to human development, it appears to have the potential for catastrophic effects within a lifetime or two.
abluegirlTHE SEA LILY
A Marine Animal with Roots in the Deep PastPrehistoric crinoid fossil [detail] (by cobalt123)
“One of the best detail views I’ve gotten of fossil crinoid, macro view of a very large fossil specimen in a slab about 6’ tall and 4 1/2” wide.”
BOTTOM: modern crinoids
Stalked crinoids have been seen to detach themselves from the ocean floor and move, probably to escape sea urchin predation.
Huge Volcano Eruptions May Have Caused The Die-Off That Paved The Way For Dino Domination
The Triassic die-off is one of 5 mass extinctions on Earth in the past 542 million years.
Excavating Evidence of A Great Extinction Along sea cliffs in southern England, geologist Paul Olsen of Columbia University’s Lamont-Doherty Earth Observatory samples rocks from near the 201,564,000-year Triassic extinction boundary. Kevin Krajick/Earth InstituteWe all know a gigantic asteroid is to blame for wiping out the dinosaurs—but what wiped out the animals that came before them? A changed climate, brought about by devastating volcanic eruptions, may have cleared the way.
New research strengthens the argument that more than 200 million years ago, massive volcano eruptions spewed gargantuan amounts of noxious gas into the atmosphere, causing catastrophic global warming and acidification of the oceans.
About 76 percent of the life forms on Earth perished, in a terrible die-off known as the Triassic-Jurassic extinction event. It wasn’t as bad as the Permian-Triassic Great Dying some 50 million years prior, but it was bad enough that half the species living on this planet disappeared. With plenty of new ecological niches to fill, dinosaurs took over the Earth for the next 135 million years.
Scientists have suspected that mega-volcanism and resulting climate change may have played a role in all this, but it was difficult to show correlation. Now researchers have the tightest link yet: A new date for the End Triassic Extinction at 201,564,000 years ago, exactly the same time as a massive outpouring of lava across all the land.
“This may not quench all the questions about the exact mechanism of the extinction itself. However, the coincidence in time with the volcanism is pretty much ironclad,” coauthor Paul Olsen, a geologist at Columbia University’s Lamont-Doherty Earth Observatory who has been investigating the boundary since the 1970s, said in a statement.This happened when all the land on Earth was connected in a megacontinent. The titanic eruptions caused a rift in this continent that ballooned into the Atlantic Ocean. Now, evidence for the cataclysm can be seen in North America, South America and Africa. Olsen took a chunk of rock from the Hudson River Palisades, a few hundred yards from the New Jersey side of the George Washington Bridge. Below, a basalt deposit near a retirement home in Clifton, N.J., shows the lava flow in gray and sedimentary rocks—signaling the extinction—in red.
Evidence of Extinction: In Clifton, New Jersey, a massive basalt flow (black rock on left) from the time of the End Triassic is exposed in a former quarry, now located behind a retirement home. Reddish sedimentary rocks signaling the extinction itself lie to the far right. Paul Olsen/Lamont-Doherty Earth Observatory
The team was not looking for fossils per se, but evidence of changes that set the stage for dinosaurs. They were able to date sedimentary deposits with great precision, matching them to certain kinds of crystals found in ancient lavas. This technique set new constraints on the die-off, and found it matches right up with the evidence of volcanism.
The actual mechanism of death is not as clear, however. Climate change is the most likely culprit, caused by massive belchings of sulfur, carbon dioxide and other toxins into the atmosphere. Acidic oceans, which would have hampered the ability of many creatures to produce their shells, is another possible explanation. The study appears today in Science.
luckyboots Asks:
scinerds Said:
Hello! I’m the admin who posted the Jurassic Park story.
You’ve got a great point! I talked a bit about the Jurassic Park/feather saga on my Tumblr a few days back before I posted the Velociraptor post on scinerds. The great thing about creative licensing is that you can stretch back to the truth, if that makes sense. Could there have been other experiments happening on the islands that we never knew about (never discussed in books or films)? Perhaps they did some experiments with bird DNA, or due to the fact they ended up thriving when they shouldn’t have, they just continued to evolve and mutate! In Jurassic Park III, the raptors had a little bit of protofeather decoration, which could be nice foreshadowing. There is so much they can do either way - whether they end up decorating some new/old dinosaurs as they are now known to have existed, or use the frog DNA as a reason they did not grow feathers.
I do believe that dropping a few explanations on their appearances in the film would be a good way to explain why they are the way they are. Definitely a lot they can do, so I’m excited to see Jurassic Park IV nonetheless.
Dinosaur-killing space rock ‘was a comet’
Scientists believe that the object that hit the earth 65 million years ago, triggering the extinction of the dinosaurs, was a comet, not an asteroid. Comets are typically smaller, but faster moving than asteroids. This one resulted in the 180-km wide Chicxulub crater in Mexico, and would have triggered the global environmental change that caused the extinction event. Here’s more from BBC News:
The space rock gave rise to a global layer of sediments enriched in the chemical element iridium, in concentrations much higher than naturally occurs; it must have come from outer space.
However, in the first part of their work, the team suggests that frequently quoted iridium values are incorrect. Using a comparison with another extraterrestrial element deposited in the impact - osmium - they were able to deduce that the collision deposited less debris than has previously been supposed.
The recalculated iridium value suggests a smaller body hit the Earth. So for the second part of their work, the researchers took the new figure and attempted to reconcile it with the known physical properties of the Chicxulub impact.
For this smaller space rock to have produced a 180km-wide crater, it must have been travelling relatively quickly. The team found that a long-period comet fitted the bill much better than other possible candidates.
“You’d need an asteroid of about 5km diameter to contribute that much iridium and osmium. But an asteroid that size would not make a 200km-diameter crater,” said Dr Moore.
“So we said: how do we get something that has enough energy to generate that size of crater, but has much less rocky material? That brings us to comets.”
National Geographic: A Velociraptor Without Feathers Isn’t a Velociraptor by Brian Switek
Jurassic Park is the greatest dinosaur movie of all time. Aside from being an exceptionally entertaining adventure, the film introduced audiences to dinosaurs that had never been seen before – hybrids of new science and bleeding-edge special effects techniques. The active, alert, and clever dinosaurs that paleontologists had recently pieced together were revived by way of exquisite puppetry and computer imagery, instantly replacing the old images of dinosaurs as swamp-dwelling dullards. Despite the various scientific nitpicks and some artistic license overreach – let’s not talk about the “Spitter” - Jurassic Park showed how science and cinema could collaborate to create something truly majestic. That’s why it’s so disappointing to hear the the next Jurassic Park sequel is going to turn its back on a critical aspect of dinosaur lives. In Jurassic Park 4, the film’s director has stated, there will be no feathery dinosaurs.
Isle of Wight girl Daisy Morris has flying prehistoric beast named after her
Daisy Morris, an amateur fossil hunter from the Isle of Wight, discovered some “bones sticking out of the sand” in 2009, when she was four years old. The fossil turned out to be a previously discovered genus of small petrosaur from the Lower Cretaceous period. The dinosaur has since been named after her, Vectidraco daisymorrisae. Her mum says: “She has a very good eye for tiny little fossils and found these tiny little black bones sticking out of the mud and decided to dig a bit further and scoop them all out. We are all very proud of her”.
The fossil has since been donated to the Natural History Museum . You can read more about Daisy and her discovery @BBC.
Giant Camels Roamed the Arctic 3.5 Million Years Ago
The fossil remains of a 3.5-million-year-old camel were found on Ellesmere Island in Canada’s northernmost territory, Nunavut.
The camel was about 30 percent bigger than modern camels and was identified using a technique called collagen fingerprinting. The finding, detailed today (March 5) in the journal Nature Communications, suggests that modern camels stemmed from giant relatives that lived in a forested Arctic that was somewhat warmer than today.
ikenbotBuzzsaw Jaw Helicoprion Was a Freaky Ratfish
Of all the vexing fossil mysteries that have confounded paleontologists, few have been as persistent as that of Helicoprion – the name given to petrified whorls of elongate teeth that look like 270 million year old renditions on the theme of buzzsaw.
What sort of animal did this Paleozoic remnant belong to, and where did the circular blade actually fit on the animal? Today, Idaho State University paleontologist Leif Tapanila and coauthors announce the answer to a conundrum that has puzzled paleontologists for over a century.
..
Tapanila and Pruitt concluded that the Helicoprion whorls really did have their buzzsaw shape in life, but they didn’t stop there. Along with their colleagues and input from Ray Troll, the researchers launched a new, detailed investigation into the museum’s Helicoprion stores.
The fossil Bendix-Almgreen described, in particular, seemed to have the potential to yield new clues through CT scans that could visualize the internal secrets of the specimen. The scans, taken at the University of Texas High-Resolution X-ray CT Facility in Austin, “came out brilliant” Tapanila says.
Not only was the fossil in better shape than expected, but the specimen elucidated two critical facets of the animal – that Helicoprion didn’t have an elongated jaw, and that it wasn’t really a shark.
Tapeworm Eggs Discovered in 270-Million-Year-Old Fossil Shark Feces.
Article via ScienceDaily: A cluster of tapeworm eggs discovered in 270-million-year-old fossilized shark feces suggests that intestinal parasites in vertebrates are much older than previously known, according to research published Jan. 30 in the open access journal PLOS ONE by Paula Dentzien-Dias and colleagues from the Federal University of Rio Grande, Brazil.
Remains of such parasites in vertebrates from this era are rare- of 500 samples examined, only one revealed the tapeworm eggs. This particular discovery helps establish a timeline for the evolution of present-day parasitic tapeworms that occur in foods like pork, fish and beef.
The fossilized eggs were found in a cluster very similar to those laid by modern tapeworms. Some of them are un-hatched and one contains what appears to be a developing larva. According to the study, “This discovery shows that the fossil record of vertebrate intestinal parasites is much older than was previously known and occurred at least 270-300 million years ago.”
The fossil described in this study is from Middle-Late Permian times, a period followed by the largest mass extinction known, when nearly 90% of marine species and 70% of terrestrial species died out.
![Tiny, Feathery Dinosaur Raises Jurassic Questions Like ‘Can I Clone It and Keep It?’
Known by many paleontologists as cutie-pieous rex.. No but seriously:
When paleontologists began discovering feathery dinosaurs during the 1990s, every find was a tantalizing glimpse at possibilities that researchers had based on bone. Now, almost seventeen years since the Sinosauropteryx splash, fluffy dinosaurs seem almost mundane. Finding yet another small, bird-like, fuzzy dinosaur doesn’t spur the same excitement that earlier discoveries did. This is not to say that these new finds are not important. Quite the contrary. With every new feathered dinosaur named, paleontologists uncover a little more context for ongoing discussions about the evolution of flight, feathers, and birds. The latest fluffy dinosaur to join the ranks – Eosinopteryx brevipenna.
Found by a commercial collector in the roughly 161 million year old stone of northeastern China’s Tiaojishan Formation, the tiny dinosaur is preserved as a virtually complete skeleton. Encircled by feather fossils, the 30 cm long dinosaur lies with its arms held out and legs bent. The theropod almost looks like it’s ready to take off running, except for the fact that the dinosaur’s head is slightly detached from the vertebral column.
Described by Royal Belgian Institute of Natural Sciences paleontologist Pascal Godefroit and coauthors in Nature Communications, Eosinopteryx is the third fluffy dinosaur known from the same deposits. The skeletally-similar Anchiornis and Xiaotingia have both been found in Tiaojishan Formation and supposedly lived around the same time. (How old these dinosaurs are, and whether they were contemporaries, is a tricky question made all the more complicated by the fact that these specimens are often purchased from commercial dealers who do not rigorously record geological information about the fossils.) Could Eosinopteryx be an Anchiornis by another name? Godefroit and colleagues argue against synonymy, citing plumage as the key difference.
Compared to Anchiornis and other closely-related feathered dinosaurs within a group called deinonychosaurs, Eosinopteryx seemed to be missing feathers. Whereas Anchiornis had long pennaceous feathers along the tail, ankles, and feet, Eosinopteryx lacked these specialized features. Rather than being a quirk of preservation, Godefroit and coauthors argue, Eosinopteryx seems to lack these feathers because they weren’t actually there. The fact that delicate, plume-like feathers were preserved on the dinosaur’s tail, for example, hints that the dinosaur’s anatomy is preserved to such a high degree that pennaceous feathers would have turned up had they been present.
The researchers also doubt that the difference in feather types was the result of changes during growth. Based upon the degree of fusion between certain bones in the skeleton, Godefroit and collaborators hypothesize that the lone Eosinopteryx specimen was a subadult or adult when it perished. The paleontologists concede that this Eosinopteryx specimen might have lacked pennaceous tail and leg feathers because it was moulting when it perished, but, based on other features, they argue that the fossil faithfully preserves the dinosaur’s true plumage. The fact that Eosinopteryx had comparatively short arms and uncurved toe claws is consistent with a life spent scurrying over the ground rather than flapping through the air.
Of course, the plumage, relationships, and behavior of Eosinopteryx are all hypotheses that are open to testing. Paleontologists aren’t totally agreed on the usefulness of bone fusion alone to estimate the ages of dinosaurs, and claw shape isn’t necessarily a good indicator of preferred habitat or natural history. The most controversial aspect of the new study may not be the behavior or age of Eosinopteryx, though, but the feathered dinosaur family tree the researchers recovered.
The evolutionary tree, created by comparing subtle traits of various dinosaurs and early birds with each other to discern relationships, found that the famous Archaeopteryx wasn’t actually an early bird, but an archaic deinonychosaur – the larger group that contains troodontids like Anchiornis and dromaeosaurids such as Velociraptor. This placement echoes the results of a controversial study, published in Nature in 2011, which proposed that Archaeopteryx, Anchiornis, and Xiaotingia formed a distinct subgroup of feathered dinosaurs that was further removed from bird ancestry than traditionally thought.
Does this mean that we should stop calling Archaeopteryx the earliest known bird? Not necessarily. “[T]his phylogeny remains only weakly supported,” Godefroit and coauthors caution, and the paleontologists point out that convergent evolution among small, feathered dinosaurs might obscure the true pattern of relationships between the feathered forms. The identity of Archaeopteryx is being questioned, and rightly so, but paleontologists have yet to fully resolve which particular lineage of dinosaur spawned the first birds.
Birds are a special lineage of coelurosaurian dinosaurs. That is a fact. But the details of when and how that transition occurred, not to mention exactly from whom, are still areas of active debate. Eosinopteryx underscores the increasingly complex pattern of feathered dinosaur evolution and bird origins. The tiny dinosaur is another point of reference in an ongoing discussion about when dinosaurs took to the air, and which particular lineage left avian heirs to the Mesozoic legacy.
[The restoration of Eosinopteryx above was created by Emily Willoughby. Check out her artwork here.]
Godefroit, P., Demuynck, H., Dyke, G., Hu, D., Escuillie, F., Claeys, P. 2013. Reduced plumage and flight ability of a new Jurassic paravian theropod from China. Nature Communications. 4, 1394. doi: 10.1038/ncomms2389](http://24.media.tumblr.com/5d7d3fca0c587cfb7042bc24018f91cd/tumblr_mhi0te1AP31qbn6nco1_500.jpg)
Tiny, Feathery Dinosaur Raises Jurassic Questions Like ‘Can I Clone It and Keep It?’
Known by many paleontologists as cutie-pieous rex.. No but seriously:
When paleontologists began discovering feathery dinosaurs during the 1990s, every find was a tantalizing glimpse at possibilities that researchers had based on bone. Now, almost seventeen years since the Sinosauropteryx splash, fluffy dinosaurs seem almost mundane. Finding yet another small, bird-like, fuzzy dinosaur doesn’t spur the same excitement that earlier discoveries did. This is not to say that these new finds are not important. Quite the contrary. With every new feathered dinosaur named, paleontologists uncover a little more context for ongoing discussions about the evolution of flight, feathers, and birds. The latest fluffy dinosaur to join the ranks – Eosinopteryx brevipenna.
Found by a commercial collector in the roughly 161 million year old stone of northeastern China’s Tiaojishan Formation, the tiny dinosaur is preserved as a virtually complete skeleton. Encircled by feather fossils, the 30 cm long dinosaur lies with its arms held out and legs bent. The theropod almost looks like it’s ready to take off running, except for the fact that the dinosaur’s head is slightly detached from the vertebral column.
Described by Royal Belgian Institute of Natural Sciences paleontologist Pascal Godefroit and coauthors in Nature Communications, Eosinopteryx is the third fluffy dinosaur known from the same deposits. The skeletally-similar Anchiornis and Xiaotingia have both been found in Tiaojishan Formation and supposedly lived around the same time. (How old these dinosaurs are, and whether they were contemporaries, is a tricky question made all the more complicated by the fact that these specimens are often purchased from commercial dealers who do not rigorously record geological information about the fossils.) Could Eosinopteryx be an Anchiornis by another name? Godefroit and colleagues argue against synonymy, citing plumage as the key difference.
Compared to Anchiornis and other closely-related feathered dinosaurs within a group called deinonychosaurs, Eosinopteryx seemed to be missing feathers. Whereas Anchiornis had long pennaceous feathers along the tail, ankles, and feet, Eosinopteryx lacked these specialized features. Rather than being a quirk of preservation, Godefroit and coauthors argue, Eosinopteryx seems to lack these feathers because they weren’t actually there. The fact that delicate, plume-like feathers were preserved on the dinosaur’s tail, for example, hints that the dinosaur’s anatomy is preserved to such a high degree that pennaceous feathers would have turned up had they been present.
The researchers also doubt that the difference in feather types was the result of changes during growth. Based upon the degree of fusion between certain bones in the skeleton, Godefroit and collaborators hypothesize that the lone Eosinopteryx specimen was a subadult or adult when it perished. The paleontologists concede that this Eosinopteryx specimen might have lacked pennaceous tail and leg feathers because it was moulting when it perished, but, based on other features, they argue that the fossil faithfully preserves the dinosaur’s true plumage. The fact that Eosinopteryx had comparatively short arms and uncurved toe claws is consistent with a life spent scurrying over the ground rather than flapping through the air.
Of course, the plumage, relationships, and behavior of Eosinopteryx are all hypotheses that are open to testing. Paleontologists aren’t totally agreed on the usefulness of bone fusion alone to estimate the ages of dinosaurs, and claw shape isn’t necessarily a good indicator of preferred habitat or natural history. The most controversial aspect of the new study may not be the behavior or age of Eosinopteryx, though, but the feathered dinosaur family tree the researchers recovered.
The evolutionary tree, created by comparing subtle traits of various dinosaurs and early birds with each other to discern relationships, found that the famous Archaeopteryx wasn’t actually an early bird, but an archaic deinonychosaur – the larger group that contains troodontids like Anchiornis and dromaeosaurids such as Velociraptor. This placement echoes the results of a controversial study, published in Nature in 2011, which proposed that Archaeopteryx, Anchiornis, and Xiaotingia formed a distinct subgroup of feathered dinosaurs that was further removed from bird ancestry than traditionally thought.
Does this mean that we should stop calling Archaeopteryx the earliest known bird? Not necessarily. “[T]his phylogeny remains only weakly supported,” Godefroit and coauthors caution, and the paleontologists point out that convergent evolution among small, feathered dinosaurs might obscure the true pattern of relationships between the feathered forms. The identity of Archaeopteryx is being questioned, and rightly so, but paleontologists have yet to fully resolve which particular lineage of dinosaur spawned the first birds.
Birds are a special lineage of coelurosaurian dinosaurs. That is a fact. But the details of when and how that transition occurred, not to mention exactly from whom, are still areas of active debate. Eosinopteryx underscores the increasingly complex pattern of feathered dinosaur evolution and bird origins. The tiny dinosaur is another point of reference in an ongoing discussion about when dinosaurs took to the air, and which particular lineage left avian heirs to the Mesozoic legacy.
[The restoration of Eosinopteryx above was created by Emily Willoughby. Check out her artwork here.]
Godefroit, P., Demuynck, H., Dyke, G., Hu, D., Escuillie, F., Claeys, P. 2013. Reduced plumage and flight ability of a new Jurassic paravian theropod from China. Nature Communications. 4, 1394. doi: 10.1038/ncomms2389
Good ol’ Ardi - Ardipithecus Ramidus
Ardipithecus ramidus was first reported in 1994; in 2009, scientists announced a partial skeleton, nicknamed ‘Ardi’.
The foot bones in this skeleton indicate a divergent large toe combined with a rigid foot – it’s still unclear what this means concerning bipedal behavior. The pelvis, reconstructed from a crushed specimen, is said to show adaptations that combine tree-climbing and bipedal activity. The discoverers argue that the ‘Ardi’ skeleton reflects a human-African ape common ancestor that was not chimpanzee-like. A good sample of canine teeth of this species indicates very little difference in size between males and females in this species.
Ardi’s fossils were found alongside faunal remains indicating she lived in a wooded environment. This contradicts the open savanna theory for the origin of bipedalism, which states that humans learned to walk upright as climates became drier and environments became more open and grassy.
Over 100 specimens of Ardipithecus ramidus have been recovered in Ethiopia. Even though it has some ape-like features (as do many other early human species), it also has key human features including smaller diamond-shaped canines and some evidence of upright walking. It may have descended from an earlier species of Ardipithecus that has been found in the same area of Ethiopia, Ardipithecus kadabba.
Ardipithecus ramidus individuals were most likely omnivores, which means they enjoyed more generalized diet of both plants, meat, and fruit. Ar. ramidus did not seem to eat hard, abrasive foods like nuts and tubers.
How do we know they were omnivores?
The enamel on Ar. ramidus teeth remains show it was neither very thick nor very thin. If the enamel was thick, it would mean Ar. ramidus ate tough, abrasive foods. If the enamel was thin, this would suggest Ar. ramidus ate softer foods such as fruit. Instead, A. ramidus has an enamel thickness between a chimpanzee’s and later Australopithecus or Homo species, suggesting a mixed diet. However, the wear pattern and incisor sizes indicate Ar. ramidus was not a specialized frugivore ( fruit-eater). Ar. ramidus probably also avoided tough foods, as they did not have the heavy chewing specializations of later Australopithecus species.
This dinosaur-era bird had a full set of teeth for crushing armored prey
Content from io9.com: ”In an unprecedented discovery, paleontologists working in China have found the fossilized remains of an ancient bird with ornamented tooth enamel. Called Sulcavis geeorum, the bird lived during the Early Cretaceous period, about 121 to 125 million years ago. And as its fine row of robust teeth indicate, it likely had a highly specialized diet much different than the beaked birds of today.
Sulcavis was an enantiornithine, an early group of birds that lived in large numbers during the dinosaur era. But unlike other birds, this new fossilized specimen features a discrete set of teeth with grooves on the inside surface, which probably strengthened them against harder food items. The bird likely used these teeth not to grind or chew, but to crush tough objects.
According to the researchers, a team led by Jingmai O’Connor, no previous bird species have any form of dental ornamentation, whether it be preserved ridges, striations, or serrated edges. It was during the Mesozoic era that other birds were losing their teeth (which they inherited from their dinosaur ancestors). O’Connor’s team is not sure why Sulcavis was so successful during the Cretaceous, only to die out. They speculate that differences in diet must have played a part, and that the teeth were not a good long-term adaptation.The study, which was published in the Journal of Vertebrate Paleontology, suggests that the teeth allowed Sulcavis to adopt a durophagous diet — a diet consisting of prey that had hard exoskeletons, including insects and crabs.
The finding greatly increases the known diversity of tooth shape in early birds, suggesting a wider array of ecological diversity among birds than previously assumed.
The study appears in the current issue of Journal of Vertebrate Paleontology (it’s not available online, but we’ll update this page with a link once it’s up).
Images by Stephanie Abramowicz.”
