Tuesday, August 31, 2010
Monday, August 30, 2010
By describing a new double-clawed and highly-unusual relative of Velociraptor, paleontologists have answered a long-standing question: what did the Late Cretaceous predatory dinosaurs in Europe look like? Balaur bondoc, described this week in Proceedings of the National Academy of Sciences, is the first reasonably complete skeleton of a meat-eating dinosaur from the final 60 million years of the Age of Dinosaurs in Europe and provides insight into an ecosystem very different from that of today. Europe at the end of the Cretaceous was awash in higher seas and was an island archipelago dominated by animals smaller and more primitive than their relatives living on larger landmasses.
"We've all been waiting for something like this, and the wait has yielded an interesting surprise," says Mark Norell, chair of the Division of Paleontology at the American Museum of Natural History and one of the authors of the research paper describing the fossil. "B. bondoc is heavy, with unexpectedly stocky limbs and fused bones. It shows just how unusual the fauna of the area was during the waning years of the dinosaur era."
"Balaur might be one of the largest predators in this ecosystem because not even a big tooth has been found in Romania after over a hundred years of research," says co-author Zoltán Csiki of the University of Bucharest. "Fragmentary remains of Balaur were already known for more than 10 years, but the morphology is so weird we didn't have any idea where to fit them."
Balaur bondoc, which means "stocky dragon," was unearthed in Romania by geologist and co-author Mátyás Vremir of the Transylvanian Museum Society. Higher sea levels at the end of the Cretaceous flooded much of present-day continental Europe, so Romania, which was an island, is now one of the best windows into Europe at the end of the Age of Dinosaurs. Other fossils discovered in these deposits include dwarf sauropods that were the size of cows and tiny duck-billed dinosaurs.
The new theropod fossil, the type specimen, is a partial skeleton that includes leg, hip, backbone, arms, hand, rib, and tail bones. But B. bondoc has 20 unique features when compared to its nearest relatives, including a re-evolved functional big toe with a large claw that can be hyperextended, presumably used to slash prey. Because there is also a large claw on the second toe, as is typical of the group of dinosaurs to which B. bondoc belongs, the new species has unusual double-clawed feet. Unique features are also found in other parts of the foot, leg, and pelvis. The feet and legs are short and stocky, with bones fused together, and the pelvis has enormous muscle attachment areas, indicating that this species was adapted for strength over speed. Finally, the hand is atrophied and some of the bones are fused, features that would have made grasping difficult. This, in combination with the leg and foot traits, indicates that the lower limbs rather than hands were used to grasp and disembowel prey.
"Balaur is a new breed of predatory dinosaur, very different from anything we have ever known," says Stephen Brusatte, a graduate student at Columbia University who is affiliated with the Museum. "Its anatomy shows that it probably hunted in a different way than its less stocky relatives. Compared to Velociraptor, Balaur was probably more of a kickboxer than a sprinter, and it might have been able to take down larger animals than itself, as many carnivores do today."
"Nevertheless, Balaur is the size of an oversized turkey and unlike what we know of the large predators from other parts of the world at the same time period, like Tyrannosaurus or Carnotaurus," says Csiki. "As European dinosaur faunas were known to be peculiar, we half-expected to find peculiar predators as well. But, as the first good record of these, Balaur surely exceeds our most daring expectations."
no time and then some.
Thursday, August 26, 2010
Wednesday, August 25, 2010
The ancient "terror bird" Andalgalornis couldn't fly, but it used its unusually large, rigid skull--coupled with a hawk-like hooked beak--in a fighting strategy reminiscent of boxer Muhammad Ali.
The agile creature repeatedly attacked and retreated, landing well-targeted, hatchet-like jabs to take down its prey, according to results of a new study published this week in the journal PLoS ONE.
The study is the first detailed look at the predatory style of a member of an extinct group of large, flightless birds known scientifically as Phorusrhacids but popularly labeled "terror birds" because of their fearsome skull and often imposing size.
Terror birds evolved about 60 million years ago in isolation in South America, an island continent until the last few million years, radiating into about 18 known species ranging in size up to the 7-foot-tall (2.1 meters) Kelenken.
Because terror birds have no close analogs among modern-day birds, their life habits have been shrouded in mystery, according to William Zamer, acting deputy director of the National Science Foundation (NSF)'s Division of Integrative Organismal Systems, which funded the research.
Now, a multinational team of scientists has performed the most sophisticated study to date of the form, function and predatory behavior of a terror bird, using CT scanning and advanced engineering methods.
"No one has ever attempted such a comprehensive biomechanical analysis of a terror bird," said study lead author Federico Degrange of the Museo de La Plata/CONICET in Argentina.
"We need to figure out the ecological role these amazing birds played if we really want to understand how the unusual ecosystems of South America evolved over the past 60 million years."
The terror bird under study is called Andalgalornis and lived in northwestern Argentina about six million years ago. It was a mid-sized terror bird, standing about 4.5 feet tall (1.4 meters) and weighing in at a fleet-footed 90 pounds (40 kg).
Like all terror birds, its skull was relatively enormous (14.5 inches or 37 centimeters) with a deep narrow bill armed with a powerful, hawk-like hook.
Paper co-author Lawrence Witmer of the Ohio University College of Osteopathic Medicine ran a complete skull of Andalgalornis through a CT scanner, giving the team a glimpse into the skull's inner architecture.
The scans revealed to Witmer, Degrange and article co-author Claudia Tambussi, also from the Museo de La Plata/CONICET, that Andalgalornis was unlike other birds because it had evolved a highly rigid skull.
"Birds generally have skulls with lots of mobility between the bones, which allows them to have light but strong skulls," said Witmer.
"But we found that Andalgalornis had turned these mobile joints into rigid beams. This guy had a strong skull, particularly in the fore-aft direction, despite having a curiously hollow beak."
The evolution of this large and rigid bony weapon was presumably linked to the loss of flight in terror birds, as well as to their sometimes gigantic sizes.
From the CT scans, Stephen Wroe, director of the Computational Biomechanics Research Group at the University of New South Wales, Australia, assembled sophisticated 3-D models of the terror bird and two living species for comparison (an eagle, and the terror bird's closest living relative, the seriema).
Using computers and software supplied by Wroe, Degrange and Karen Moreno of the Université Paul Sabatier in Toulouse, France, applied an approach known as Finite Element Analysis to simulate and compare the biomechanics of biting straight down (as in a killing bite), pulling back with its neck (as in dismembering prey) and shaking the skull from side to side (as in thrashing smaller animals, or when dealing with larger struggling prey).
Color images created by the program show cool-blue areas where stresses are low and white-hot areas where stresses get dangerously high.
The simulations supported the CT-based anatomical results.
"Relative to the other birds considered in the study, the terror bird was well-adapted to drive the beak in and pull back with that wickedly recurved tip of the beak," remarked Wroe, "but when shaking its head from side to side, its skull lights up like a Christmas tree."
A key part of the analysis was determining how hard a bite Andalgalornis could deliver.
To examine bite force in birds in general, Degrange and Tambussi worked with zookeepers at the La Plata Zoo to get a seriema and an eagle to chomp down on their bite meter.
"We discovered that the bite force of Andalgalornis was a little lower than we expected, and weaker than the bite of many carnivorous mammals of about the same size," Degrange said.
"Andalgalornis may have compensated for this weaker bite by using its powerful neck muscles to drive its strong skull into prey like an axe."
The team's results give new insight into the lifestyle of a unique avian predator.
Its skull, though strong vertically, was weak from side to side; its hollow beak was in danger of catastrophic fracture if Andalgalornis grappled too vigorously with large struggling prey.
Instead, the study shows that the terror bird engaged in an elegant style more like that of Muhammad Ali--a repeated attack-and-retreat strategy with well-targeted, hatchet-like jabs.
Once killed, the prey would have been ripped into bite-sized morsels by the powerful neck pulling the head straight back or, if possible, swallowed whole.
Freakin parrot from hell!
Also covered here, here, and here.
Tuesday, August 24, 2010
A modern-day space race to land an unmanned probe on the Moon is emerging between Russia and India on one side and China on the other.
After months of negotiations, Russian and Indian engineers have started working on a robotic mission together.
This would see the landing of a small four-wheeled rover on to the surface of the Earth's celestial neighbour.
It is set to launch in 2013, to roughly match the scheduled lunar landing of China's Chang'e-3 spacecraft.
Whichever team gets there first, it would be the first human hardware to function on the lunar surface since the Soviet Luna-24 spacecraft returned to Earth with Moon's soil samples in 1976.
Known in Russia as Luna-Resource and in India as Chandrayaan-2, the joint mission will include an Indian-built lunar orbiter and the Russian-built landing platform both launched by a single Indian rocket.
The Russian-built four-legged platform will deliver around 35kg of scientific equipment to the lunar surface and release a 15kg Indian-built robotic rover.
Despite being a far cry from the 750kg Soviet Lunokhod rovers, which rolled across the lunar landscape in the 1970s, the tiny Indian electric vehicle is still expected to provide scientific data, thanks to miniaturisation of technology.
"We do understand that, first of all, it is a demonstration of the Indian presence on the surface of the Moon," Aleksandr Zakharov, a leading scientist at the Space Research Institute (IKI) in Moscow told BBC News.
"However, it will have a TV camera onboard, and we also asked our Indian partners to include a miniature manipulator, so it could sample soil beyond the reach of the robotic arm of the (stationary Russian) lander."
The rover and all of its scientific instruments are expected to be Indian-built, even though India is free to solicit foreign participation, Mr Zakharov said.
And the X Prize teams on another...in a way...maybe. lol. How funny.
Fossils of what could be the oldest animal bodies have been discovered in Australia, pushing back the clock on when animal life first appeared on Earth to at least 70 million years earlier than previously thought.
The results suggest that primitive sponge-like creatures lived in ocean reefs about 650 million years ago. Digital images of the fossils suggest the animals were about a centimeter in size (the width of your small fingertip) and had irregularly shaped bodies with a network of internal canals.
The shelly fossils, found beneath a 635 million-year-old glacial deposit in South Australia, represent the earliest evidence of animal body forms in the current fossil record. Previously, the oldest known fossils of hard-bodied animals were from two reef-dwelling organisms that lived around 550 million years ago.
Researchers have identified controversial fossils of soft-bodied animals that date to the latter part of the Ediacaran period between 577 and 542 million years ago.
The research was funded by the National Science Foundation's (NSF) Division of Earth Sciences.
Really no time. Rockets, kids, daycare, Avrora in kindergarten, lyuda's school. Feel lucky I have time to even post at all.
Thursday, August 19, 2010
Wednesday, August 11, 2010
Researchers have found a primitive Earth mantle reservoir on Baffin Island in the Canadian Arctic. Geologist Matthew Jackson and his colleagues from a multi-institution collaboration report the finding--the first discovery of what may be a primitive Earth mantle--this week in the journal Nature.
The Earth's mantle is a rocky, solid shell that is between the Earth's crust and the outer core, and makes up about 84 percent of the Earth's volume. The mantle is made up of many distinct portions or reservoirs that have different chemical compositions.
Scientists had previously concluded that the Earth was slightly older than 4.5 billion years old, but had not found a piece of the Earth's primitive mantle.
Until recently, researchers generally thought that the Earth and the other planets of the solar system were chondritic, meaning that the mantle's chemistry was thought to be similar to that of chondrites--some of the oldest, most primitive objects in the solar system. Assuming a chondritic model of the Earth, a piece of the primitive mantle would have certain isotope ratios of the chemical elements of helium, lead and neodymium.
The model that the Earth was chondritic was called into question with a discovery five years ago by a team at the Carnegie Institution of Washington, which suggested the ratio of neodymium on Earth was higher than what would be expected if the Earth were indeed chondritic.
That finding changed the neodymium ratio expected in the primitive mantle and in turn, changed where researchers should be looking to find evidence of a primitive mantle. According to the lead author, Matthew Jackson, "We had been looking under the wrong rock."
Since many of the ancient rocks have melted over time, finding a piece of the primitive mantle means studying lavas. Lavas retain the same isotopic composition of the rocks that have melted into the lava. Therefore, testing the lava's composition is identical to testing the original rock's composition.
When the assumption about the neodymium ratio was altered, Jackson and his colleagues knew they should take a look at lava samples from Baffin Island, since those samples contained the correct ratios of helium and neodymium. They discovered that the lavas also had the correct ratio for lead. The lead isotopes suggest that the samples from Baffin Island date the lava's mantle source reservoir to between 4.55 and 4.45 billion years old, only a little younger than the age of the Earth. The lava sample comes from an ancient rock that melted 62 million years ago.
When the researchers studied the composition of the lava found at Baffin Island, they discovered that the sample had the correct ratios of all three chemical elements--helium, lead, and the new non-chronditic neodymium ratio. This discovery suggests that the sample from Baffin Island is the first evidence for the oldest mantle reservoir.
This study challenges the idea that the Earth has a chondritic primitive mantle and according to Matthew Jackson is, "suggesting an alternative." One possibility, according to Jackson, is that "the early Earth went through a differentiation event and the Earth's crust was extracted from the early mantle and is now hidden in the deep earth; the hidden crust and the mantle found on Baffin Island would sum to chondritic."
Big potential wrinkle there.
The evolutionary stories of the Swiss Army Knife and the Big Mac just got a lot longer. An international team of scientists led by Dr. Zeresenay Alemseged from the California Academy of Sciences has discovered evidence that human ancestors were using stone tools and consuming meat from large mammals nearly a million years earlier than previously documented. While working in the Afar Region of Ethiopia, Alemseged's "Dikika Research Project" team found fossilized bones bearing unambiguous evidence of stone tool use—cut marks inflicted while carving meat off the bone and percussion marks created while breaking the bones open to extract marrow. The bones date to roughly 3.4 million years ago and provide the first evidence that Lucy's species, Australopithecus afarensis, used stone tools and consumed meat. The research is reported in the August 12 issue of the journal Nature.
Although the butchered bones may not look like particularly noteworthy fossils to the lay person, Alemseged can hardly contain his excitement when he describes them. "This find will definitely force us to revise our text books on human evolution, since it pushes the evidence for tool use and meat eating in our family back by nearly a million years," he explains. "These developments had a huge impact on the story of humanity."
Until now, the oldest known evidence of butchering with stone tools came from Bouri, Ethiopia, where several cut-marked bones were dated to about 2.5 million years ago. The oldest known stone tools, dated to around the same time, were found at nearby Gona, Ethiopia. Although no hominin fossils were found in direct association with the Gona tools or the Bouri bones, an upper jaw from an early Homo species dated to about 2.4 million years ago was found at nearby Hadar, and most paleoanthropologists believe the tools were made and used only by members of the genus Homo.
The new stone-tool-marked fossil animal bones from Dikika have been dated to approximately 3.4 million years ago and were found just 200 meters away from the site where Alemseged's team discovered "Selam" in 2000. Dubbed "Lucy's Daughter" by the international press, Selam was a young Australopithecus afarensis girl who lived about 3.3 million years ago and represents the most complete skeleton of a human ancestor discovered to date.
awesome. no time again.
Tuesday, August 10, 2010
The Gondwana supercontinent underwent a 60-degree rotation across Earth's surface during the Early Cambrian period, according to new evidence uncovered by a team of Yale University geologists. Gondwana made up the southern half of Pangaea, the giant supercontinent that constituted the Earth's landmass before it broke up into the separate continents we see today. The study, which appears in the August issue of the journal Geology, has implications for the environmental conditions that existed at a crucial period in Earth's evolutionary history called the Cambrian explosion, when most of the major groups of complex animals rapidly appeared.
The team studied the paleomagnetic record of the Amadeus Basin in central Australia, which was part of the Gondwana precursor supercontinent. Based on the directions of the ancient rock's magnetization, they discovered that the entire Gondwana landmass underwent a rapid 60-degree rotational shift, with some regions attaining a speed of at least 16 (+12/-8) cm/year, about 525 million years ago. By comparison, the fastest shifts we see today are at speeds of about four cm/year.
This was the first large-scale rotation that Gondwana underwent after forming, said Ross Mitchell, a Yale graduate student and author of the study. The shift could either be the result of plate tectonics (the individual motion of continental plates with respect to one another) or "true polar wander," in which the Earth's solid land mass (down to the liquid outer core almost 3,000 km deep) rotates together with respect to the planet's rotational axis, changing the location of the geographic poles, Mitchell said.
The debate about the role of true polar wander versus plate tectonics in defining the motions of Earth's continents has been going on in the scientific community for decades, as more and more evidence is gathered, Mitchell said.
In this case, Mitchell and his team suggest that the rates of Gondwana's motion exceed those of "normal" plate tectonics as derived from the record of the past few hundred million years. "If true polar wander caused the shift, that makes sense. If the shift was due to plate tectonics, we'd have to come up with some pretty novel explanations."
Whatever the cause, the massive shift had some major consequences. As a result of the rotation, the area that is now Brazil would have rapidly moved from close to the southern pole toward the tropics. Such large movements of landmass would have affected environmental factors such as carbon concentrations and ocean levels, Mitchell said.
"There were dramatic environmental changes taking place during the Early Cambrian, right at the same time as Gondwana was undergoing this massive shift," he said. "Apart from our understanding of plate tectonics and true polar wander, this could have had huge implications for the Cambrian explosion of animal life at that time."
uh. Yeah. To say the least. If it did this, I'd be very surprised if there wasn't a lot of volcanism. 60 degrees though?!
It ought to be noted that the Hummingbird can carry up to 8 Hellfire missiles. It can - although I doubt with a full load out like that - fly for 24 hours and 2500 miles.
Monday, August 09, 2010
Thursday, August 05, 2010
The U.S. government should lead development of a nuclear thermal propulsion system for a future Mars mission and leave new heavy-lift launchers to commercial entities, Space Exploration Technologies (SpaceX) says.
Unveiling conceptual plans for a family of Falcon X and XX future heavy-lift vehicles at last week’s AIAA Joint Propulsion conference here, SpaceX McGregor rocket development facility director Tom Markusic said, “Mars is the ultimate goal of SpaceX.”
The company, which until now has focused mostly on development of vehicles to transport cargo and humans to low Earth orbit (LEO), believes its Falcon 1 and Falcon 9 launchers could be evolved into a heavy-lift family that will provide the basis for a Mars-capable architecture.
For the transition from Earth to Mars, however, SpaceX believes nuclear thermal is the preferred propulsion means for the piloted aspect of the mission, while solar-electric power could be used to transport supplies.
The U.S. government “should take the lead on nuclear and commercial industry should take the lead on building heavy-lift launch vehicles,” Markusic says. “Low-level propulsion technology research and development should be government-led, with a transition to flight development in 2025.”
Markusic’s call flies in the face of SpaceX’s usual advocacy for industrially driven competition and Commercial Orbital Transportation Services (COTS)-like procurement. However, he says “the government should only lead the propulsion element development where there is no existing commercial capability, or a high risk of capital loss.”
For cargo to Mars, SpaceX’s architecture suggests tugs powered by clusters of solar-electric powered thrusters. The 100-kw. tugs each would carry around 4 metric tons of payload and take 390 days for the round trip.
The plan envisages a fleet of up to 10 tugs rotating between LEO and Mars orbit, with vehicles being serviced and turned at a terminus based on the International Space Station.
For landing and ascending on Mars or its moon Phobos, SpaceX is proposing a liquid oxygen (Lox)/methane powered propulsion system capable of delivering a payload of approximately 35 metric tons. In-situ derived methane could be used for fuel, while existing engines now in development by ATK or Xcor Aerospace could provide the basis for initial units.
SpaceX’s long-discussed Merlin 2 Lox/rocket propellant-fueled engine, capable of a projected 1.7 million lb. of thrust at sea level and 1.92 million lb. in a vacuum, would provide the power for the Falcon X and XX heavy launch vehicles.
Slated to be introduced on more capable variants of the Falcon 9 Heavy, the Merlin 2 “could be qualified in three years for $1 billion,” Markusic says.
Three Merlin 2s would power the first stage of Falcon X, a 300-ft. plus tall vehicle capable of placing 38,000 kg. in LEO.
A growth development, dubbed Falcon X Heavy, would employ nine engines clustered in three cores. Collectively these would generate 10.8 million lb. of thrust at liftoff and boost 125,000 kg. to orbit. The ultimate launch vehicle, the Falcon XX, stands as tall as the Saturn V, is configured with six engines in a single core and is designed to lift 140,000 kg. to LEO.
No time to comment.
Wednesday, August 04, 2010
Fossils of an ancient crocodile with mammal-like teeth have been discovered in the Rukwa Rift Basin of Tanzania, scientists report in this week's issue of the journal Nature. The unusual creature is changing the picture of animal life at 100 million years ago in what is now sub-Saharan Africa.
"If you only looked at the teeth, you wouldn't think this was a crocodile. You would wonder what kind of strange mammal or mammal-like reptile it is," said study lead author Patrick O'Connor, associate professor of anatomy in the Ohio University College of Osteopathic Medicine.
The scientists describe the new species of notosuchian crocodyliform as a small animal—"its head would fit in the palm of your hand," O'Connor said—that wasn't as heavily armored as other crocodiles, except along the tail. Other aspects of its anatomy suggest it was a land-dwelling creature that likely feasted on insects and other small animals to survive.
O'Connor and his international research team, funded by the U.S. National Science Foundation and the National Geographic Society, found a complete specimen of the crocodile in 2008, and now have recovered portions of seven different individuals in southwestern Tanzania. The tooth row with molar-like teeth initially puzzled many experts. Other ancient and living crocodiles typically boast relatively simple, conical teeth that serve to seize and tear prey; they swallow flesh in large chunks.
The molar teeth of the new species, named Pakasuchus (Paka is the Ki-Swahili name for cat and souchos is Greek for crocodile), possessed shearing edges for processing food, similar in form to the teeth of some mammalian carnivores.
"Once we were able to get a close look at the teeth, we knew we had something new and very exciting," O'Connor said.
The research team's discovery that the animals had heavily plated tails but relatively unarmored bodies with gracile limbs suggests that the creatures were quite mobile. They probably actively foraged on land, unlike water-dwelling crocodiles.
The new species isn't a close relative of modern crocodilians, but is a member of a very successful side branch of the crocodyliform lineage that lived during the Mesozoic Era, O'Connor said.
While the specimens of the newly discovered animal and its close relatives are unusual, the study suggests that the creatures were abundant during the middle Cretaceous, from around 110 million until 80 million years ago.
Also at Nat Geo.
A unique blob-like creature that lived in the ocean approximately 425 million years ago is revealed in a 3D computer model in research published today in the journal Biology Letters. The model is helping researchers to understand what primitive species on early Earth looked like and how they might have evolved into the types of creatures that are on Earth today.
The scientists, from Imperial College London, have developed a detailed 3D model of the only known fossilised specimen in the world of a creature called Drakozoon. The specimen was found by one of the team approximately 6 years ago in the Herefordshire Lagerstätte, one of England's richest deposits of soft-bodied fossils.
Drakozoon lived in the ocean during the Silurian Period, 444 to 416 million years ago, and today's model hints at how it lived.
The research reveals that Drakozoon was a cone-shaped, blob-like creature with a hood and it probably had a leathery exterior skin. It appears to have survived in the ocean by attaching itself to hard surfaces such as rock. It was approximately 3mm long, and used filament-bearing tentacles to catch and eat organic particles in seawater. It pulled its hood down over its body for protection against predators, pulling it back again to expose its tentacles when danger passed.
Dr Mark Sutton, from the Department of Earth Science and Engineering at Imperial College London, says:
"Excitingly, our 3D model brings back to life a creature that until recently no one knew even existed, and provides us with a window into the life of Drakozoon. We think this tiny blob of jelly survived by clinging onto rocks and hard shelled creatures, making a living by plucking microscopic morsels out of seawater. By looking at this primitive creature, we also get one tantalising step closer to understanding what the earliest creatures on Earth looked like."
Scientists have debated what the first relatives of all creatures on Earth may have resembled and how their bodies evolved. Some scientists think the creatures had repeated units, similar to a caterpillar with its many segments and legs, while others think that their bodies were structured in more free-form ways, similar to slugs.
In today's study, the researchers analysed their 3D model and discovered that Drakozoon had eight deep ridges on either side of its body. They suggest that these deep ridges are the genetic remnants from a time when Drakozoon had a body made of repeated units, supporting the theory that the earliest creatures on Earth were also made of repeated units.
The study shows that Drakozoon was an early member of a major group of invertebrate species called lophophorates. The best known lophophorates are the brachiopods, a type of spineless shellfish that are some of the most common fossils from the Silurian Period. The team found their Drakozoon specimen clinging onto the fossilised shell of a brachiopod.
Being on rotation after the power upgrade really, really sux, however.
Tuesday, August 03, 2010
Taking old World War II photos, Russian photographer Sergey Larenkov carefully photoshops them over more recent shots to make the past come alive. Not only do we get to experience places like Berlin, Prague, and Vienna in ways we could have never imagined, more importantly, we are able to appreciate our shared history in a whole new and unbelievably meaningful way.
Words fail me. This is just astounding.
Monday, August 02, 2010
Geological Timing Differences:
Starting from the deepest geological time period, the divergences began with the Permian Period. The PT Extinction never happened in this tour de force. Rather than ending the Permian at 251 MYA, witht he eruptions of the Siberian Traps, the traps erupted over a much longer period that lasted from the Guadelupean Extinction to 245 MYA. Their effect was tolerated a lot more by the biosphere and the Permian - now XenoPermian - extends all the way up with its evolving Paleozoic ecosystems until 199.6 MYA. This is marked by the XenoPermian-Jurassic Extinctions. This marked the end of the Paleozoic and the start of the Mesozoic.
Obviously, the Mesozoic has been curtailed since the Triassic has simply ceased to exist under the Xenopermian TL. However, through a fluke of orbital mechanics, the Cretaceous and by extension the Mesozoic was extended to 55.8 MYA. The rock that ended the Mesozoic instead of landing in Chicxulub, Mexico on the Yucatan Peninsula, the great splat hit what would have been Bristol, England and caused a slightly milder mass extinction. The Cretaceous is now divided up into the Upper, Middle and Lower Epochs.
The Allozoic picks up where the Mesozoic left off and there is a distinct difference between the Allozoic and the Cenozoic. The Paleocene is history and the Paleogene and Tertiary is also circumscribed.
Next up, Paleoenvironmental differences between our Permian & Triassic and the XenoPermian. This will actually be in the next week.
For previous XenoPermian posts look here.