Monday, February 06, 2012

XenoPermian Biota of the Ural Sea: Graviloricanasus roma, a pseudochelonid

THE XENOPERMIAN OF THE URAL SEA

The Xenopermian is a collaborative effort between Scott, Raven, Zach and myself to outline a very different, speculative world. In some ways this is not all that different than the exercises of Dougal Dixon, After Man and The New Dinosaurs. Rather than speculating on what the dinosaurs would be like if they had not gone extinct, much like his New Dinosaurs or the Spec World project , or project into the future with After Man or The Future is Wild, our team asked the question of ‘what if the Permian Extinction did not happen?

This is the first post about the fauna of the Xenopermian in the Ural Sea region. We have talked about a ‘fossil’ and a faux controversy associated it with. We have talked about the geological staging differences in the XenoPermian timeline, and have even talked about the differences in the world in general under such a different period. We have generalized about the fauna, but now we want to get into specifics.

Despite the fact that the world is largely dominated by the different clades of therapsids, other major lineages are major participants in the ecology of the XenoPermian. Rather than start with a therapsid, we decided to talk about a parareptile first. That first critter is a pareiasaur. That begs the questions of what is a parareptile and what is a pareiasaur?

What are the parareptiles?

Parareptiles are a clade of amniotes that have been in the past often labeled ‘anapsids.’ Amniotes, vertebrate animals that have an amniotic sack and, for the most part, are terrestrial, were divided into different groups based on the shape and structure of their skulls. Synapsids are those that had a single hole in the skull for muscle to attach. Modern mammals are the only current survivors of that clade. Diapsids are the second group and currently comprise reptiles and birds except perhaps turtles. That will be explained later. Diapsids have two holes in their skulls for anchoring their jaw muscles. Finally, there was another large traditional group, the anapsids. These amniotes had no holes in their skulls. Traditionally, this included turtles as the sole surviving members of the clade, but with a vast number of extinct relatives. There was another group, the euryapsids, but they were a smaller group that was largely centered around the extinct marine reptiles.



It turns out that the shape and number of holes in the skull were not quite the best, most accurate way to group the different clades of animals. It is possible for diapsids to redevelop, for whatever reason, the anapsid (no hole) cranial condition. This was discovered when cladistics became the tool of choice by paleontologists to determine evolutionary relationships between fossils.

A number of families and genuses were shuffled around. Interestingly, the synapsids were untouched as a group. The diapsids largely held together, but the anapsids were slaughtered as far as a ‘natural group’ (meaning closely related and descended from a common ancestor). Some ‘anapsids’ were actually diapsids that had evolved or re-evolved the anapsid condition. When the arguing was done, the skull type that has been referred to as ‘anapsid’ applied to some species that were actually descended from the diapsids and many that were not. The proposal was made to rename the remaining anapsids that were not closely related to diapsids ‘parareptiles’ (next to reptiles) and accepted by the community as a whole.

The placement of turtles is fairly contentious. The pour critters are fought over whether they are members of a group that went through parallel evolution and evolved the anapsid condition from a diapsid ancestor or actually belonged back as a sole surviving members of the parareptiles. There is strong evidence that they are actually diapsids now from studying microRNA, but cladistic analysis by and large, well, almost consistently shows them to be parareptiles. This argument, as far as I can tell, has yet to be resolved.

Other than turtles, parareptiles comprise many fascinating and interesting groups. The seemingly first bipedal animals, the bolosaurs, are members of the group. The procolonphids are another interesting member. The nycoleters and their relatives are the first amniotes, it appears, to have evolved the middle ear from the apparently deaf ancestral condition. (Yes, the basal amniotes were deaf it seems, but that is another discussion for another time) Finally, most importantly for the Xenopermian and this post, the clade that we care about most is the pareiasaurs.

What were the pareiasaurs?



The pareiasaurs were one of the earliest large megafauna. They were herbivores that grew to be as large as ten feet long and were built like tanks. In fact, the pareiasaurs were the largest herbivores of their time and were built such that they housed a massive gut for digesting the tough plants of their era. Their teeth looked leaf like and not unlike those of iguanas

They were also tanks, as noted, and had scutes, osteoderms, in their skin. Most likely this was to deal with the very large and deadly gorgonopsids. Some have projected that the gorgons and pareiasarus were in an arms race where the armor of these critters built up to deal with the ever increasing size and viciousness of the canines of the gorgons.

If you want to know more, we recommend the basics at Wikipedia and the more extensive website at the University of California at Berkeley.

In our time line, they went extinct during the Permian Extinction. However, our timeline iwe actually live in s not that of the Xenopermian. The Xenopermian didn’t have a PT Event to wipe out all life. True, the Siberian Traps did erupt, but more gradually and over the course of millions of years instead of violently in a relatively short burst. This caused a period of evolutionary innovation and turnover, but did not wipe out many of the large clades. The pareiasaurs benefitted from that time of innovation and went on to develop into interesting clades.

Elginiformes, Scutosauroformes and Therischia, oh my!

Xenopermian Pareiasauria cladogram


Technically, all of the surviving pareiasaurian of the Xenopermian are from Therischia. This is a particular clade within the pareiasaurian lineage. In paleontology, cladistics dictates that the different fossils found are evaluated as relatives rather than ancestors. Its highly unlikely, honestly, that any one fossil species found gave rise to others that are related since the fossil record is infamously and enormously incomplete. However, in our world that the Xenopermian, we know exactly who is descended from whom. Or rather what from what. In our timeline we have two different lineages of pareiasaurs that have survived through to the 15 million year mark before the Xenopermian-Jurassic Mass Extinction.

The first derives from the dwarf pareiasaur, Elginia, and is very common as solitary animals scattered about the more marginal habitats. There are several species and genuses in the Megavongo, for example. The Barred Quillosaur being an excellent example. They all have a generally sprawled stance and are heavy armored, but in a manor reminiscent of the thorny devils of modern day Australia. Though with some parallels to the styracaosaurian ceraptopsians (sans nasal and brow horns). However, while being very species and even somewhat genera diverse the elginiformes are not the most diverse nor “dominant” of the two pareiasaur lineages. That would be the scutosauriformes.

Scutosaurus was a rather large beast by modern standards. With being around ten feet long and a chest like a barrel, it weighed in over 1000 lbs. It had several innovations that made it – without the Permian Extinction – a potential founder of a new and important lineage. Some of these were the stance changes, massive expansion of the digestive tract, probable homeothermy and extensive increases in the armoring scutes. With the power of the massive selectivity of being the creators of this timeline, Scutosaurus went forth and begat several new clades. Three of those clades have survived into the late XenoPermian.

The most basal of them is Deimocephalia. These are large, sometimes up to 4.5m (15 ft) animals. They move in bull dominated herds over vast distances. They give some basic parental care to their young although this is pretty limited to guarding the nest and forming a protective barrier while en route between the young and the outside world. Their name, terror heads, derives from the fact that they have very fanciful, species specific, crown and frill ornamentation. This is more extreme in the males than females, but present in both. Additionally their skulls have thickened for further protection. They retain the ancestral scute armor of the scutosauriformes. This clade is most common in the plains and other open territories, but also present in smaller forms in the more open forests of the Xenopermian world that permit herding.

The next most derived clade is that of the Juggernautids. These are massive animals that in terms of mass, if not length, rival the sauropods of our time line. Between 6 meters (20 ft) and some species being as long as 10m (over 32 ft), they have developed the brachiosaurian layout with the forelegs being much longer than the hind. They tower over the landscape with heights between 4.5m (15ft) to as much as 6m (20ft) in the largest species. They do NOT have the extended long neck of the sauropods while one somewhat longer than the standard pareiasaurs in proportion. The juggernautids did not just get their name from their size, but also from the fact that they radically shape the environment from which they live. The bulldoze paths for food and often reduce forests to copses that are either inaccessible to the juggernautid, or ‘managed’ such that there is not an interior that the juggernautid cannot reach for feeding. Forests where juggernautids exist have a strange almost garden like appearance what seem like streets when viewed from above. Juggernautids are not noted for their parenting skills even if they mate for life. Their young are heavily armoured and their scutes tend to still be present but more scattered across the body as the animal grows, these primary scutes are surrounded by thinner, but still tough secondary scutes, which in turn are followed by tertiary scute development between those with straight scaly skin separating the rosarettes of the largest creatures.

Neither of the above clades is present around the Ural Sea. However, the final clade is.

The Pseudochelonids are a large, heavy herbivores. They are called the pseudochelonids (false turtles) because of their heavily armored carapaces. They have some elements that are convergent on turtles in that regard, with the scutes often fusing with the broad ribs in some genuses. Visually, most look closer to anklyosaurs rather than turtles, but the first example found of the clade was the most extreme in its armour development and set the nomenclature for the whole group.

Some of the unifying characteristics are that the ribs are broad and flat, almost forming a fused shell dorsally. This is often covered by scutes that are interlocking. The skulls are extremely thick and heavy: even their eyelids are armoured. The brain case is relatively small for an animal of their relative size as well. However, the olfactory and aural regions are relatively developed to support what is a very good sense of smell and moderately developed middle ear. They all have vestigal or nonexistent tails. Their scutes cover more than their torso region and extend down onto the legs. Like all scutosauriformes, they have a parasagittal stance.

They are by and large solitary animals, but do not have defined ranges except during mating season and tolerate one another quite well otherwise. They do not give parental care to their young, building a rocky nest and then abandoning them. The newly hatched young once their skin dries and hardens become what some atl paleontologists call ‘jaw breakers’ (fractognathine stage) because their scutes are so thick and dense. Their main sources of mortality once they have become jaw breakers are not predators, but rather disease and drowning. Post fractgnathinous stage starts when the animal reaches 1 meter (40 inches) in length because of the inability of the body to continue to scale up with such armor. When the animal has reached 1.5m (five feet) in length, it often is sexually mature, but while still heavily armoured, in danger from its primary predator: the gorgonopsids. In fact, the pseudochelonids and the gorgonopsids are in something of an arms race: heavier armour vs stronger bites and better piercing saber teeth.

Graviloricanasus roma



In the Ural Sea region the dominant member, both most common and largest, is Graviloricanasus roma (Roman’s heavily armored nose). Named for the discoverer, Thomas Roman, it became a bit of an in-joke because the olfactory organ – nose – was quite impressive and the great Roman Nose was too good to pass up. The belief is that the olfactory sense was highly developed for two reasons. The first was that it allowed G. roma to smell its primary predators and locate when particular foods were present.

Predation Around the Ural Sea

The gorgonopsids of the Ural Sea region were G roma's primary predators and were noted for scent marking their territories. A cross genera territorial struggle between the Baurbarops millerensis and Dispathadontis gracilis, the two large top predators in the Ural Sea left some very impressive olfactory battlefields. B. millerensis was rarer and larger gorgon largely preying on dicynodonts, especially, but definitely not exclusively, what has been popularly called the ‘Walrodonts.’ Other preferred dicynodonts included the other less specialized aquatic dicynodonts, such has the so called "Hippodonts," "desmodonts," and others. However, given the beach front territory of adult B milernensis and the sea weed dining habits of G roma, B millerensis will opportunistically predate this pseudochelonid. The sheer size and strength of B millernesis makes this predation possible despite the extensive armor of G roma.

Dispathadontis
, while it could and would take other prey, was largely a specialist in pseudochelonids. In the Ural Sea region, this specifically means G roma. While B millerensis is noted for its brute force hunting style, D gracilis is more finessed. D gracilis is noted for hunting in mated pairs. The pairing will corner a G roma and then attempt to rip out its wind wipe through the use of their sabre teeth.

The only other predator of note of G roma is the ambush predator crurodont, Venofirodens macbethii, a member of the clade descended from the therocephalian Euchambersia. V macbethii relies, like all of its clade, on the delivery of a poisonous bite to its prey for it take-down mechanism rather than traumatic damage to an organism.

Of course, as eggs, G roma is at risk from a variety of potential predators. The cynodont genus, Acerdens, the small Xenopermian theropods, niictodonts, and even opportunistic raids from the trees by suminids and foliosensids can and do take their toll on the unhatched.

Diet Peculiarities

One of the benefits of the nasal system of G roma was that it also allowed for scenting food sources other than the norm for consumption. One of those is seaweed. The seaweeds that swept up from the very mixed waters of the Ural Sea are a nutritious addition to the normal diet. When the tide goes out, G roma often comes out of the coastal forest to dine, as pictured here. This is, however, the point that G roma is most in risk of predation from B millerensis.

However, for the majority of its nutritional needs, G roma browses within the Ural Sea coastal forests. Its diet is largely comprised of ferns and seed plant leaves. Its preference is not for horsetails or their allies, but will consume these during hard times.

Ecological Impact

G roma's impact on the local ecology is moderate, but appreciable. Its nothing like its remote cousins, the Juggernautids, but it is far from trivial. Within the Ural Sea coastal forests, wide avenues are present from the passage of G roma to and from certain locales, especially watering holes. This in turn, has stimulated seed baring plants to develop into upper canopy participants by leaving potential places for trees with wide boughs to collect light where the horsetails are unable to. Ginkgoes and others have taken advantage of this.

Other significant impacts are the specialization of Dispathadontis and the development of scatosporic ferns (dug heaps often sprout ferns in a massive way from consuming through an odd life cycle of certain fern species in the Ural Sea region).

Legacy

Graviloricanasus roma would last as a species for approximately three million years. Its genus would last to nearly the Xenopermian-Jurassic Extinction. All parieasaurs would go extinct during the XJ Event and take with them their "tormentors" and largely specialist carnivores, the gorgonopsids. It would be over 100 million years before another walking tank would arise, but it would not be another parareptile and it would happen outside the Xenopermian, well within the Mesozoic and embedded in the alternate Cretaceous. And thus, outside the scope of this project as yet.


Author's note: Here's our first critter. I hope that you folks enjoyed it. My apologies for the delay. Next up will be a therapsid. A notable little tree hugger for that matter. It will be a bit before it appears here, but hopefully not too long. I need yet another cladogram and its a far more complicated one than the above!

Wednesday, February 01, 2012

First Plants Caused Ice Age During the Ordovician?


New research reveals how the arrival of the first plants 470 million years ago triggered a series of ice ages. Led by the Universities of Exeter and Oxford, the study is published today (1 February 2012) in Nature Geoscience.

The team set out to identify the effects that the first land plants had on the climate during the Ordovician Period, which ended 444 million years ago. During this period the climate gradually cooled, leading to a series of 'ice ages'. This global cooling was caused by a dramatic reduction in atmospheric carbon, which this research now suggests was triggered by the arrival of plants.

Among the first plants to grow on land were the ancestors of mosses that grow today. This study shows that they extracted minerals such as calcium, magnesium, phosphorus and iron from rocks in order to grow. In so doing, they caused chemical weathering of the Earth's surface. This had a dramatic impact on the global carbon cycle and subsequently on the climate. It could also have led to a mass extinction of marine life.

The research suggests that the first plants caused the weathering of calcium and magnesium ions from silicate rocks, such as granite, in a process that removed carbon dioxide from the atmosphere, forming new carbonate rocks in the ocean. This cooled global temperatures by around five degrees Celsius.

In addition, by weathering the nutrients phosphorus and iron from rocks, the first plants increased the quantities of both these nutrients going into the oceans, fuelling productivity there and causing organic carbon burial. This removed yet more carbon from the atmosphere, further cooling the climate by another two to three degrees Celsius. It could also have had a devastating impact on marine life, leading to a mass extinction that has puzzled scientists.

The team used the modern moss, Physcomitrella patens for their study. They placed a number of rocks, with or without moss growing on them, into incubators. Over three months they were able to measure the effects the moss had on the chemical weathering of the rocks.

They then used an Earth system model to establish what difference plants could have made to climate change during the Ordovician Period.


I've heard this put forward for the Devonian, but not the Ordovician. For that matter, the Azolla Event is another proposed biologically driven climate change. We'll see how this plays out. The timing is...tough...to prove, but we do know that life even nonsapient/sophont does impact climate.

Volcanoes, Not the Maunder Minimum Caused the Little Ice Age?


A mysterious, centuries-long cool spell, dubbed the Little Ice Age, appears to have been caused by a series of volcanic eruptions and sustained by sea ice, a new study indicates.

The research, which looked at chemical clues preserved in Arctic vegetation as well as other data, also pinpointed the start of the Little Ice Age to the end of the 13th century.

During the cool spell, which lasted into the late 19th century, advancing glaciers destroyed northern European towns and froze the Thames River in London and canals in the Netherlands, places that are now ice-free. There is also evidence it affected other continents.

"This is the first time anyone has clearly identified the specific onset of the cold times marking the start of the Little Ice Age," said Gifford Miller, a geological sciences professor at the University of Colorado, Boulder, and the lead study researcher. "We also have provided an understandable climate feedback system that explains how this cold period could be sustained for a long period of time."

The cause appears to have been massive tropical volcanic eruptions, which spewed tiny particles called aerosols into the atmosphere. While suspended in the air, the aerosols reflect solar radiation back into space, cooling the planet below.

The cooling was sustained after the aerosols had left the atmosphere by a sea-ice feedback in the North Atlantic Ocean, the researchers believe. Expanding sea ice would have melted into the North Atlantic Ocean, interfering with the normal mixing between surface and deeper waters. This meant the water flowing back to the Arctic was colder, helping to sustain large areas of sea ice, which, in turn, reflect sunlight back into the atmosphere. The result was a self-sustaining feedback loop.

Miller and colleagues came to these conclusions by looking at radiocarbon dates — based on how much of the radioactive form of carbon they contain — from dead plants revealed by melting ice on Baffin Island, in the Canadian Arctic. Their analysis found that many plants at both high and low altitudes died between A.D. 1275 and A.D. 1300 — evidence that Baffin Island froze over suddenly. Many plants also appeared to have died at around A.D. 1450, an indication of a second major cooling.

These periods coincide with two of the most volcanically active half centuries in the past millennium, according to the researchers.

Let's see if they can provide more support. Its intriguing, but caution is in order.

Friday, January 27, 2012

What Happened Prior to the Carbon Prior to the Marinoan Glaciations (Snowball Earth)


In a study published in the journal Geology, scientists at the University of Miami (UM) Rosenstiel School of Marine and Atmospheric Science suggest that the large changes in the carbon isotopic composition of carbonates which occurred prior to the major climatic event more than 500 million years ago, known as 'Snowball Earth,' are unrelated to worldwide glacial events.

"Our study suggests that the geochemical record documented in rocks prior to the Marinoan glaciation or 'Snowball Earth' are unrelated to the glaciation itself," said UM Rosenstiel professor Peter Swart, a co-author of the study. "Instead the changes in the carbon isotopic ratio are related to alteration by freshwater as sea level fell."

In order to better understand the environmental conditions prior to 'Snowball Earth', the research team analyzed geochemical signatures preserved in carbonate rock cores from similar climactic events that happened more recently — two million years ago — during the Pliocene-Pleistocene period.

The team analyzed the ratio of the rare isotope of carbon (13C) to the more abundant carbon isotope (12C) from cores drilled in the Bahamas and the Enewetak Atoll in the Pacific Ocean. The geochemical patterns that were observed in these cores were nearly identical to the pattern seen prior to the Marinoan glaciation, which suggests that the alteration of rocks by water, a process known as diagenesis, is the source of the changes seen during that time period.

Prior to this study, scientists theorized that large changes in the cycling of carbon between the organic and inorganic reservoirs occurred in the atmosphere and oceans, setting the stage for the global glacial event known as 'Snowball Earth'.

"It is widely accepted that changes in the carbon isotopic ratio during the Pliocene-Pleistocene time are the result of alteration of rocks by freshwater," said Swart. "We believe this is also what occurred during the Neoproterozoic. Instead of being related to massive and complicated changes in the carbon cycle, the variations seen in the Neoproterozoic can be explained by simple process which we understand very well."

Scientists acknowledge that multiple sea level fluctuations occurred during the Pliocene-Pleistocene glaciations resulting from water being locked up in glaciers. Similar sea-level changes during the Neoproterozoic caused the variations in the global carbon isotopic signal preserved in the older rocks, not a change in the distribution of carbon as had been widely postulated.


I don't see the paper online as yet...

All These Worlds...



Wednesday, January 18, 2012

Greenhouse Gases Postpone (Cancel?) Next Glacial Cycle

Unprecedented levels of greenhouse gases in the Earth's atmosphere are disrupting normal patterns of glaciation, according to a study co-authored by a University of Florida researcher and published online Jan. 8 in Nature Geoscience.

The Earth's current warm period that began about 11,000 years ago should give way to another ice age within about 1,500 years, according to accepted astronomical models. However, current levels of carbon dioxide are trapping too much heat in the atmosphere to allow the Earth to cool as it has in its prehistoric past in response to changes in Earth's orbital pattern. The research team, a collaboration among University College London, University of Cambridge and UF, said their data indicate that the next ice age will likely be delayed by tens of thousands of years.

That may sound like good news, but it probably isn't, said Jim Channell, distinguished professor of geology at UF and co-author.

"Ice sheets like those in western Antarctica are already destabilized by global warming," said Channell. "When they eventually slough off and become a part of the ocean's volume, it will have a dramatic effect on sea level." Ice sheets will continue to melt until the next phase of cooling begins in earnest.

The study looks at the prehistoric climate-change drivers of the past to project the onset of the next ice age. Using astronomical models that show Earth's orbital pattern with all of its fluctuations and wobbles over the last several million years, astronomers can calculate the amount of solar heat that has reached the Earth's atmosphere during past glacial and interglacial periods.

"We know from past records that Earth's orbital characteristics during our present interglacial period are a dead ringer for orbital characteristics in an interglacial period 780,000 years ago," said Channell. The pattern suggests that our current period of warmth should be ending within about 1,500 years.

However, there is a much higher concentration of greenhouse gases trapping the sun's heat in the Earth's atmosphere now than there was in at least the last several million years, he said. So the cooling that would naturally occur due to changes in the Earth's orbital characteristics are unable to turn the temperature tide.

Over the past million years, the Earth's carbon dioxide levels, as recorded in ice core samples, have never reached more than 280 parts per million in the atmosphere. "We are now at 390 parts per million," Channell said. The sudden spike has occurred in the last 150 years.

For millions of years, carbon dioxide levels have ebbed and flowed between ice ages. Orbital patterns initiate periods of warming that cause ocean circulation to change. The changes cause carbon dioxide-rich water in the deep ocean to well up toward the surface where the carbon dioxide is released as a gas back into the atmosphere. The increase in atmospheric carbon dioxide then drives further warming and eventually the orbital pattern shifts again and decreases the amount of solar heat that reaches the Earth.

"The problem is that now we have added to the total amount of CO2 cycling through the system by burning fossil fuels," said Channell. "The cooling forces can't keep up."


1. Duh.

2. This may well be a permanent off ramp for Ice Age we have been in.

3. There might have been interglacial ending on-ramps we missed before and are missing right now.

4. Keep in mind it took over 50k years for the last time there was a huge build up in CO2 like the modern one took over 50k years for the environment to recover...and it didn't go back to what it was before.

5. The main question is whether or not we are going to have a Neo-Eocene (hot, wet) or Neo-Oligocene (hot dry).

NorAm Mammalian Fauna Diversity Shifts with Climate

(original artist here)
History often seems to happen in waves – fashion and musical tastes turn over every decade and empires give way to new ones over centuries. A similar pattern characterizes the last 65 million years of natural history in North America, where a novel quantitative analysis has identified six distinct, consecutive waves of mammal species diversity, or "evolutionary faunas." What force of history determined the destiny of these groupings? The numbers say it was typically climate change.

"Although we've always known in a general way that mammals respond to climatic change over time, there has been controversy as to whether this can be demonstrated in a quantitative fashion," said Brown University evolutionary biology Professor Christine Janis. "We show that the rise and fall of these faunas is indeed correlated with climatic change – the rise or fall of global paleotemperatures – and also influenced by other more local perturbations such as immigration events."

Specifically, of the six waves of species diversity that Janis and her Spanish collaborators describe online this week in the Proceedings of the National Academy of Sciences, four show statistically significant correlations with major changes in temperature. The two transitions that show a weaker but still apparent correlation with the pattern correspond to periods when mammals from other continents happened to invade in large numbers, said Janis, who is the paper's senior and second author.

Previous studies of the potential connection between climate change and mammal species evolution have counted total species diversity in the fossil record over similar time periods. But in this analysis, led by postdoctoral scholar Borja Figueirido, the scientists asked whether there were any patterns within the species diversity that might be significant. They were guided by a similar methodology pioneered in a study of "evolutionary faunas" in marine invertebrates by Janis' late husband Jack Sepkoski, who was a paleontologist at the University of Chicago.

What the authors found is six distinct and consecutive groupings of mammal species that shared a common rise, peak and decline in their numbers. For example, the "Paleocene fauna" had largely given way to the "early-middle Eocene fauna" by about 50 million years ago. Moreover, the authors found that these transfers of dominance correlated with temperature shifts, as reflected in data on past levels of atmospheric oxygen (determined from the isotopes in the fossilized remains of deep sea microorganisms).

By the numbers, the research showed correlations between species diversity and temperature change, but qualitatively, it also provided a narrative of how the traits of typical species within each wave made sense given the changes in vegetation that followed changes in climate. For example, after a warming episode about 20 million years in the early Miocene epoch, the dominant vegetation transitioned from woodland to a savannah-like grassland. It is no surprise, therefore, that many of the herbivores that comprised the accompanying "Miocene fauna" had high-crowned teeth that allowed them to eat the foods from those savannah sources.


Original paper here.

Wednesday, January 11, 2012

Tasmanian Triassic Dicynodont Found

A Tasmanian couple on a quiet walk down to the beach a few years ago discovered a fossil that scientists say is 250 million years old.

Bob and Penny Tyson found the fossilised remains of a dicynodont, a tusked plant-eating animal that's believed to be a distant ancestor of modern mammals.

Roughly the size of a cow, it had two tusks and a horny beak.

Queensland Museum palaeontologist Andrew Rozefelds says the dicynodont lived on every continent, including Antarctica.

The ABC reports that until now, the only specimen previously found in Australia was in Queensland almost 30 years ago.

He describes the dicynodont as a ''strange-looking beast''.

''They had tusks at the front of their skull, which makes you think maybe they were a carnivore, but in fact they were a plant eater.

''They had slightly splayed legs, so their posture was quite different to say some of the modern mammals you see and they're very, very distantly related to modern mammals.''


I don't see a paper at the JVP. However, considering the journal is a little outdated from the last time they updated what's online, I'm not surprised. Previously, in Tasmania the predominant fossils were temnospondyls. And not much else.

Tuesday, January 10, 2012

Even Nastier Siberian Traps

Around 250 million years ago, at the end of the Permian geologic period, there was a mass extinction so severe that it remains the most traumatic known species die-off in Earth's history. Although the cause of this event is a mystery, it has been speculated that the eruption of a large swath of volcanic rock in Russia called the Siberian Traps was a trigger for the extinction. New research from Carnegie's Linda Elkins-Tanton and her co-authors offers insight into how this volcanism could have contributed to drastic deterioration in the global environment of the period. Their work is published January 9 in Earth and Planetary Science Letters.

The end-Permian mass extinction saw the sudden loss of more than 90 percent of marine species and more than 70 percent of terrestrial species. The fossil record suggests that ecological diversity did not fully recover until several million years after the main pulse of the extinction. This suggests that environmental conditions remained inhospitable for an extended period of time.

Volcanic activity in the Siberian Traps has been proposed as one of the mechanisms that may have triggered the mass extinction. Gases released as a result of Siberian magmatism could have caused environmental damage. For example, perhaps sulfur particles in the atmosphere reflected the sun's heat back into space, cooling the planet; or maybe chlorine and other chemically similar nonmetal elements called halogens significantly damaged the ozone layer in the stratosphere.

The team designed experiments to examine these possibilities.

Led by Benjamin Black of the Massachusetts Institute of Technology, the group included Elkins-Tanton, formerly of MIT and now director of Carnegie's Department of Terrestrial Magnetism, Michael C. Rowe of Washington State University, and Ingrid Ukstins Peate of the University of Iowa.

The geology of the Siberian Traps is comprised of flood basalts, which form when giant lava eruptions coat large swaths of land or ocean floor with basaltic lava. This lava hardens into rock formations. The team investigated concentrations of sulfur, chlorine and fluorine (another halogen) that were dissolved in tiny samples of ancient magma found within basalt samples from the Siberian Traps. These small frozen droplets, which preserve a record of volcanic gases from the time of the eruption 250 million years ago, are called melt inclusions.

Sulfur, chlorine, and fluorine gasses could have been released into the atmosphere from eruptions spewing out of large fissures, which is common in basalt flood formation. Plumes escaping from these cracks could have reached the stratosphere. If sulfur, chlorine, and fluorine made it to the upper atmosphere, these gasses could have cause a wide array of adverse climate events, including temperature change and acid rain.

Based on their findings, the team estimated that between 6,300 and 7,800 gigatonnes of sulfur, between 3,400 and 8,700 gigatonnes of chlorine, and between 7,100 and 13,700 gigatonnes of fluorine were released from magma in the Siberian Traps during the end of the Permian period.


Anyone have the paper itself? I've not been able to find it on the server.

Friday, January 06, 2012

Siberian Traps Were Meaner Than We Knew

Explosive eruption of coal and basalt and the end-Permian mass extinction

1. Darcy E. Ogden (a)
2. Norman H. Sleep (b,*)


a. Institute of Geophysics and Planetary Physics, Scripps Institution of Oceanography, University of California, San Diego, 1156 Gilman Drive, La Jolla, CA 92093-0225; and

b. Department of Geophysics, Mitchell Building, 397 Panama Mall, Stanford University, Stanford CA 94305

* To whom correspondence should be addressed. E-mail: norm@stanford.edu.

Abstract:

The end-Permian extinction decimated up to 95% of carbonate shell-bearing marine species and 80% of land animals. Isotopic excursions, dissolution of shallow marine carbonates, and the demise of carbonate shell-bearing organisms suggest global warming and ocean acidification. The temporal association of the extinction with the Siberia flood basalts at approximately 250 Ma is well known, and recent evidence suggests these flood basalts may have mobilized carbon in thick deposits of organic-rich sediments. Large isotopic excursions recorded in this period are potentially explained by rapid venting of coal-derived methane, which has primarily been attributed to metamorphism of coal by basaltic intrusion. However, recently discovered contemporaneous deposits of fly ash in northern Canada suggest large-scale combustion of coal as an additional mechanism for rapid release of carbon. This massive coal combustion may have resulted from explosive interaction with basalt sills of the Siberian Traps. Here we present physical analysis of explosive eruption of coal and basalt, demonstrating that it is a viable mechanism for global extinction. We describe and constrain the physics of this process including necessary magnitudes of basaltic intrusion, mixing and mobilization of coal and basalt, ascent to the surface, explosive combustion, and the atmospheric rise necessary for global distribution.


Explosive coal eruptions and mass mercury poisoning. Halogen emitting lakes and ozone layer depletion. Its definitely time for a rewrite of my PT Extinction post.

...in my copious amounts of spare time.

On Titan the Rain Mainly Falls on the Plains in Spring and Fall

Saturn's largest moon, Titan, is an intriguing, alien world that's covered in a thick atmosphere with abundant methane. With an average surface temperature of a brisk -297 degrees Fahrenheit (about 90 kelvins) and a diameter just less than half of Earth's, Titan boasts methane clouds and fog, as well as rainstorms and plentiful lakes of liquid methane. It's the only place in the solar system, other than Earth, that has large bodies of liquid on its surface.

The origins of many of these features, however, remain puzzling to scientists. Now, researchers at the California Institute of Technology (Caltech) have developed a computer model of Titan's atmosphere and methane cycle that, for the first time, explains many of these phenomena in a relatively simple and coherent way.

In particular, the new model explains three baffling observations of Titan. One oddity was discovered in 2009, when researchers led by Caltech professor of planetary science Oded Aharonson found that Titan's methane lakes tend to cluster around its poles—and noted that there are more lakes in the northern hemisphere than in the south.

Secondly, the areas at low latitudes, near Titan's equator, are known to be dry, lacking lakes and regular precipitation. But when the Huygens probe landed on Titan in 2005, it saw channels carved out by flowing liquid—possibly runoff from rain. And in 2009, Caltech researchers discovered raging storms that may have brought rain to this supposedly dry region.

Finally, scientists uncovered a third mystery when they noticed that clouds observed over the past decade—during summer in Titan's southern hemisphere—cluster around southern middle and high latitudes.

Scientists have proposed various ideas to explain these features, but their models either can't account for all of the observations, or do so by requiring exotic processes, such as cryogenic volcanoes that spew methane vapor to form clouds. The Caltech researchers say their new computer model, on the other hand, can explain all these observations—and does so using relatively straightforward and fundamental principles of atmospheric circulation.

"We have a unified explanation for many of the observed features," says Tapio Schneider, the Frank J. Gilloon Professor of Environmental Science and Engineering. "It doesn't require cryovolcanoes or anything esoteric." Schneider, along with Caltech graduate student Sonja Graves, former Caltech graduate student Emily Schaller (PhD '08), and Mike Brown, the Richard and Barbara Rosenberg Professor and professor of planetary astronomy, have published their findings in the January 5 issue of the journal Nature.

Schneider says the team's simulations were able to reproduce the distribution of clouds that's been observed—which was not the case with previous models. The new model also produces the right distribution of lakes. Methane tends to collect in lakes around the poles because the sunlight there is weaker on average, he explains. Energy from the sun normally evaporates liquid methane on the surface, but since there's generally less sunlight at the poles, it's easier for liquid methane there to accumulate into lakes.

But then why are there more lakes in the northern hemisphere? Schneider points out that Saturn's slightly elongated orbit means that Titan is farther from the sun when it's summer in the northern hemisphere. Kepler's second law says that a planet orbits more slowly the farther it is from the sun, which means that Titan spends more time at the far end of its elliptical orbit, when it's summer in the north. As a result, the northern summer is longer than the southern summer. And since summer is the rainy season in Titan's polar regions, the rainy season is longer in the north. Even though the summer rains in the southern hemisphere are more intense—triggered by stronger sunlight, since Titan is closer to the sun during southern summer—there's more rain over the course of a year in the north, filling more lakes.

In general, however, Titan's weather is bland, and the regions near the equator are particularly dull, the researchers say. Years can go by without a drop of rain, leaving the lower latitudes of Titan parched. It was a surprise, then, when the Huygens probe saw evidence of rain runoff in the terrain. That surprise only increased in 2009 when Schaller, Brown, Schneider, and then–postdoctoral scholar Henry Roe discovered storms in this same, supposedly rainless, area.

No one really understood how those storms arose, and previous models failed to generate anything more than a drizzle. But the new model was able to produce intense downpours during Titan's vernal and autumnal equinoxes—enough liquid to carve out the type of channels that Huygens found. With the model, the researchers can now explain the storms. "It rains very rarely at low latitudes," Schneider says. "But when it rains, it pours."

The new model differs from previous ones in that it's three-dimensional and simulates Titan's atmosphere for 135 Titan years—equivalent to 3,000 years on Earth—so that it reaches a steady state. The model also couples the atmosphere to a methane reservoir on the surface, simulating how methane is transported throughout the moon.

The model successfully reproduces what scientists have already seen on Titan, but perhaps what's most exciting, Schneider says, is that it also can predict what scientists will see in the next few years. For instance, based on the simulations, the researchers predict that the changing seasons will cause the lake levels in the north to rise over the next 15 years. They also predict that clouds will form around the north pole in the next two years. Making testable predictions is "a rare and beautiful opportunity in the planetary sciences," Schneider says. "In a few years, we'll know how right or wrong they are.


Its a frozen Tanith!

A Few Xmas Pix




Its been a while since I put up some family pix. Here's my daughter, Avrora, now age 6, and my son, Orest, now 2.

Another PT Extinction Factor: Mercury Poisoning


Scientists have uncovered a lot about the Earth's greatest extinction event that took place 250 million years ago when rapid climate change wiped out nearly all marine species and a majority of those on land. Now, they have discovered a new culprit likely involved in the annihilation: an influx of mercury into the eco-system.

"No one had ever looked to see if mercury was a potential culprit. This was a time of the greatest volcanic activity in Earth's history and we know today that the largest source of mercury comes from volcanic eruptions," says Dr. Steve Grasby, co-author of a paper published this month in the journal Geology. "We estimate that the mercury released then could have been up to 30 times greater than today's volcanic activity, making the event truly catastrophic." Grasby is a research scientist at Natural Resources Canada and an adjunct professor at the University of Calgary.

[...]

During the late Permian, the natural buffering system in the ocean became overloaded with mercury contributing to the loss of 95 per cent of life in the sea.

"Typically, algae acts like a scavenger and buries the mercury in the sediment, mitigating the effect in the oceans," says lead-author Dr. Hamed Sanei, research scientist at Natural Resources Canada and adjunct professor at the University of Calgary. "But in this case, the load was just so huge that it could not stop the damage."

[...]

The mercury deposition rates could have been significantly higher in the late Permian when compared with today's human-caused emissions. In some cases, levels of mercury in the late Permian ocean was similar to what is found near highly contaminated ponds near smelters, where the aquatic system is severely damaged, say researchers


Looking more and more like my PT Extinction post needs an update. It has been almost 6 years. (wow) And I have STILL not finished my other paleo posts. :(

Thursday, January 05, 2012

Tuesday, December 06, 2011

Varanopids Coexisted with More Advanced Synapsids

(Heleosaurus, a varanopid)
A species of ancient predator with saw-like teeth, sleek bodies and a voracious appetite for meat survived a major extinction at a time when the distant relatives of mammals ruled the earth.

A detailed description of a fossil that scientists identify as a varanopid "pelycosaur" is published in the December issue of Naturwissenschaften – The Science of Nature. Professors Sean Modesto from Cape Breton University, and Robert Reisz from University of Toronto Mississauga provide evidence that a group of ancient, agile predators called varanopids survived for more than 35 million years, and co-existed with more advanced animals.

Modesto and the team performed a detailed examination of the partial skull and jaw of the youngest known primitive mammal-like animal, which they believe lived over 260 million years ago in the Permian Period. The fossils are from rocks forming the Pristerognathus Assemblage Zone of the Beaufort Group in South Africa.

"These animals were the most agile predators of their time, sleek-looking when compared to their contemporaries," says Reisz. "They seem to have survived a major change in the terrestrial fauna that occurred during the Middle Permian, a poorly understood extinction event in the history of life on land."

According to Modesto, who was once a student at U of T Mississauga, "these ancient animals really looked like modern goannas or monitor lizards, but are actually more closely related to mammals."

The fossil revealed teeth that are strongly flattened, curved towards the throat and with finely serrated cutting edges typical of hypercarnivores--animals with a diet that consists of more than 70 per cent meat.

Modesto and his colleagues concluded that these varanopids had a longer co-existence with animals that eventually evolved into mammals than previously believed. They suggest that the dental and skeletal design of varanopids, reminiscent of the Komodo dragon of today, may have contributed to their long survival and their success.


no time. But VERY interesting.

Spinops sternbergorum: ANOTHER New Ceratopsian





Sheesh. Ceratopsians were the freakin NorAm bunnies of the Late Cretaceous.

(very nice Andy)

PrePhanerozoic Prone to Snowball Events?


Two University of Colorado Boulder researchers who have adapted a three-dimensional, general circulation model of Earth's climate to a time some 2.8 billion years ago when the sun was significantly fainter than present think the planet may have been more prone to catastrophic glaciation than previously believed.

The new 3-D model of the Archean Eon on Earth that lasted from about 3.8 billion years to 2.5 billion years ago, incorporates interactions between the atmosphere, ocean, land, ice and hydrological cycles, said CU-Boulder doctoral student Eric Wolf of the atmospheric and oceanic sciences department. Wolf has been using the new climate model -- which is based on the Community Earth System Model maintained by the National Center for Atmospheric Research in Boulder -- in part to solve the "faint young sun paradox" that occurred several billion years ago when the sun's output was only 70 to 80 percent of that today but when geologic evidence shows the climate was as warm or warmer than now.

In the past, scientists have used several types of one-dimensional climate models -- none of which included clouds or dynamic sea ice -- in an attempt to understand the conditions on early Earth that kept it warm and hospitable for primitive life forms. But the 1-D model most commonly used by scientists fixes Earth's sea ice extent at one specific level through time despite periodic temperature fluctuations on the planet, said Wolf.

"The inclusion of dynamic sea ice makes it harder to keep the early Earth warm in our 3-D model," Wolf said. "Stable, global mean temperatures below 55 degrees Fahrenheit are not possible, as the system will slowly succumb to expanding sea ice and cooling temperatures. As sea ice expands, the planet surface becomes highly reflective and less solar energy is absorbed, temperatures cool, and sea ice continues to expand."


This is interesting since it seems to be rather contrary to the general consensus that the earth was actually a lot warmer based on isotopic geological data.

Came in Email: Tenure Track Professorship at UIUC

UNIVERSITY OF ILLINOIS AT URBANA CHAMPAIGN
Department of Atmospheric Sciences
School of Earth, Society, and Environment

—Tenure Track Assistant or Tenure Track/Tenured Associate Professor Search—


The Department of Atmospheric Sciences within the School of Earth, Society, and Environment at the University of Illinois at Urbana-Champaign invites applications for a full-time, tenure-track/tenured faculty position at the rank of Assistant or Associate Professor in climate science. The position is a nine-month academic appointment with a target start date of August 16, 2012.

The area of research, within the context of climate science, is open. Possible areas of emphasis include, but are not limited to, causes of past and future climate change; studies of climate and climate change at regional to global scales using numerical modeling, data analysis, and/or remote sensing techniques; climate change impacts and the mitigation of, and adaptation to future impacts of a changing climate. Candidates with exceptional strengths in other related research areas are also welcome to apply.

The successful candidate must have a Ph.D. degree by the date of appointment. The candidate must show the potential to establish a quality research and teaching program and collaborate effectively with other faculty. For consideration at the Associate level, the candidate must also demonstrate a strong external funding and publication record. A tenured Associate Professor appointment is possible for a candidate with the appropriate research credentials who has demonstrated excellence in teaching at either or both the graduate and undergraduate levels, commensurate with tenure guidelines at the University of Illinois at Urbana-Champaign.

The Department currently comprises 10 faculty, 5 emeritus faculty, 8 affiliated and adjunct faculty, 1 lecturer, 1 instructor, 9 research scientists, 51 graduate students, and 80 undergraduates. The members of the Department work in a broad range of research areas. Opportunities are available for collaborations with departments across the university, with linkages already existing with the Departments of Geography and Geology within the School of Earth, Society, and Environment, the Illinois State Water Survey, the National Center for Supercomputing Applications (NCSA), the Electrical and Civil Engineering Departments and many others. More information about the department can be found at www.atmos.illinois.edu, and about the School of Earth, Society and Environment at www.earth.illinois.edu.

A competitive salary, commensurate with qualifications and experience, and benefits package will be offered. To ensure full consideration applications must be submitted online by December 15, 2011. Create your U of I application through http://jobs.illinois.edu and upload your application materials: cover letter, vita, list of publications, record of research funding, teaching record, description of research and teaching interests, and names and email addresses of at least 3 references. Applicants may be interviewed before the closing date; however, no hiring decision will be made until after that date.

Questions can be addressed to Prof. Atul Jain, Chair of the Search Committee, at Email: jain1@illinois.edu or Phone: 217-333-2128.

The University of Illinois is an Affirmative Action /Equal Opportunity Employer and welcomes individuals with diverse backgrounds, experiences, and ideas who embrace and value diversity and inclusivity. (www.inclusiveillinois.illinois.edu)

Kepler 22B: A Potentially Habitable Planet


Also check out the Habitable Exoplanet Catalog. Nifty press release about the latter here.

Thursday, November 17, 2011

Duration of the Permian Extinction

"This is the first paper to provide rates of such massive extinction," says Dr. Charles Henderson, professor in the Department of Geoscience at the University of Calgary and co-author of the paper: Calibrating the end-Permian mass extinction. "Our information narrows down the possibilities of what triggered the massive extinction and any potential kill mechanism must coincide with this time."

About 95 percent of marine life and 70 percent of terrestrial life became extinct during what is known as the end-Permian, a time when continents were all one land mass called Pangea. The environment ranged from desert to lush forest. Four-limbed vertebrates were becoming diverse and among them were primitive amphibians, reptiles and a group that would, one day, include mammals.

Through the analysis of various types of dating techniques on well-preserved sedimentary sections from South China to Tibet, researchers determined that the mass extinction peaked about 252.28 million years ago and lasted less than 200,000 years, with most of the extinction lasting about 20,000 years.

"These dates are important as it will allow us to understand the physical and biological changes that took place," says Henderson. "We do not discuss modern climate change, but obviously global warming is a biodiversity concern today. The geologic record tells us that 'change' happens all the time, and from this great extinction life did recover."


That's far and away the shortest time period that I've heard for the PT. I'd be interested in what other contrasting sources have to show.

Protoceratops Nest Full of Babies

A 70-million-year-old nest of the dinosaur Protoceratops andrewsi has been found with evidence that 15 juveniles were once inside it, according to a paper in the latestJournal of Paleontology.

While large numbers of eggs have been associated with other dinosaurs, such as the meat-eating Oviraptor or certain duck-billed hadrosaurs, finding multiple juveniles in the same dino nest is quite rare.


This would be the strongest evidence yet of parental care of ceratopsians. That has been a topic of considerable arguments as of late. In fact, one of the papers in the book, Horns and Beaks, iirc, argued that ceratopsians abandoned their young to form their own pre breeding herds in NorAm. Now Protoceratops is not Triceratops by any means, but being related as closely as they (relatively) are makes it more likely that the NorAm ceratopsians gave as much parental care.

Wednesday, November 16, 2011

Are There Near Surface Liquid Water Aquifers on Europa?

Three-Dimensionally Preserved Integument Reveals Hydrodynamic Adaptations in the Extinct Marine Lizard Ectenosaurus (Reptilia, Mosasauridae)


Three-Dimensionally Preserved Integument Reveals Hydrodynamic Adaptations in the Extinct Marine Lizard Ectenosaurus (Reptilia, Mosasauridae)

1. Johan Lindgren (a,*)
2. Michael J. Everhart (b)
3. Michael W. Caldwell(c)

a. Department of Earth and Ecosystem Sciences, Lund University, Lund, Sweden
b. Sternberg Museum of Natural History, Fort Hays State University, Hays, Kansas, United States of America
c. Department of Earth and Atmospheric Sciences, and Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada

* E-mail: johan.lindgren@geol.lu.se

Abstract:

The physical properties of water and the environment it presents to its inhabitants provide stringent constraints and selection pressures affecting aquatic adaptation and evolution. Mosasaurs (a group of secondarily aquatic reptiles that occupied a broad array of predatory niches in the Cretaceous marine ecosystems about 98–65 million years ago) have traditionally been considered as anguilliform locomotors capable only of generating short bursts of speed during brief ambush pursuits. Here we report on an exceptionally preserved, long-snouted mosasaur (Ectenosaurus clidastoides) from the Santonian (Upper Cretaceous) part of the Smoky Hill Chalk Member of the Niobrara Formation in western Kansas, USA, that contains phosphatized remains of the integument displaying both depth and structure. The small, ovoid neck and/or anterior trunk scales exhibit a longitudinal central keel, and are obliquely arrayed into an alternating pattern where neighboring scales overlap one another. Supportive sculpturing in the form of two parallel, longitudinal ridges on the inner scale surface and a complex system of multiple, superimposed layers of straight, cross-woven helical fiber bundles in the underlying dermis, may have served to minimize surface deformation and frictional drag during locomotion. Additional parallel fiber bundles oriented at acute angles to the long axis of the animal presumably provided stiffness in the lateral plane. These features suggest that the anterior torso of Ectenosaurus was held somewhat rigid during swimming, thereby limiting propulsive movements to the posterior body and tail.

Tuesday, November 08, 2011

Return to the XenoPermian




A Quick Intro:

The XenoPermian Period is a fictitious, alternate geological period that takes place because we hand wave away the Permian Extinction. The assumed point of departure is that the Permian Extinction never takes place. The reason for this is that the Siberian Traps are defused and their eruptions happen over a much longer period of time. This has knock-on effects. One of them being that the world's geography is different and another being that evolution has gone in rather different directions, too.

Scott, Raven, Zach and I have been working on this for some time. We'd hoped to be further along than we are, but there have been multiple setbacks and everyone has been dealing with other projects and life in general. I either had the choice of waiting until the project was further along - which would mean probably another year - or going ahead and unveiling what we have so far.

With that in mind, I have decided to start showing off what we have. I will be putting up one XenoPermian post every other week. This will space out the posts enough that maybe we might be able to get something else done prior to the last post and reduce the lag getting new artwork done.

Geography and Areas of Interest

A world is a big place. Covering the whole world is rather difficult even in a fantasy world like the XenoPermian. This is doubly difficult because we want to give a "real" sampling of the ecologies. One of the criticisms we have for Dougal Dixon is that he does such a tepid sampling that the world feels incredibly unfinished. We realized part way through we can do better, but not even get as close as we wanted to get this done right. Even then, when we considered a better than tepid attempt, but less than boiling, we realized the world was simply too big. To that end, we settled on six places to cover, with a seventh possible if we had time (ha!). The six places are Arctica, Ural Sea, Megavongo, Transpangean Mountains, Karoo and Conan Doyle's Relica.


Let's run through the five and exhibit some of the high level characteristics of each environ and the biota there.

Arctica:

Arctica is as close to a tundra as can exist under the conditions of the XenoPermian. It has very seasonal weather. This is no surprise given that the whole environment is above the Arctic Circle. While there are some shrub like vegetation, in the form of various conifers, the vast majority of the plants present are ferns. They sprout during the start of spring as the sun moves above the horizon and then die as the sunsets for winter. Life in the north polar region is tough, albeit not as tough as Arctic of our Holocene. Temperatures hover around freezing in the winter and get quite warm in the summer. Snow dusts and covers, but no more than what can happen in, say, the Midwestern states of the US in relative spring. That's nontrivial, but not what happens in the depths of winter of our Holocene. Since vegetation is sparse in winter, most herds of animals out migrate to the more southern reaches.

Animal life is dominated thoroughly by the therapsids. While archosaurs are present, the parareptiles and nonarchosaurian diapsids are largely not. The waters are filled with temnospondyls and lepospondyls, though there are no known reptilomorphs. Despite the presence of the macrofauna, the biggest presence is actually insect and a huge number of archaic invertebrate detrivores that are active even in winter munching up the dead ferns and fertilizing for the next spring.

Megavongo:

The Megavongo is a vast outletless river delta that covers a huge area in what would have been North America. This is similar to the Okavango Delta in modern Africa, but on a far, far grander scale. Life during the dry season is much like living in a desert, even one you would fine in modern Arizona or southern New Mexico, but when the megamonsoon rains hit the Transpangean Mountains, a fraction, albeit a still vast inundation, runs down the far side of the mountains and into the dry desert. The model is much like what happens in the Ethiopian Highlands for the Okavango Delta and Nile River.

Life here is harsh and dry for most of the year. Seasonal ferns mixed with specialized horsetails and lots of seed plants, especially cycads and conifers. The most inland fringes of the delta, furthest away from the seasonal water source nearly salt flats.

The fauna here is dominated by migrants. Animals conduct impressive migrations from the foothills of the Transpangaean Mountains and the coasts of the Panthalassa and Tethys consume and breed. All clades, parareptilian, diapsid & archosarian, and therapsid participate. Of those that stay between the wet seasons, active or aestivating, there is surprising diversity amongst the clades, though shockingly low on the species level.

Transpangean Mountains:

These are the mountains that straddle and divide the vast Pangaea supercontinent. Due to the fact that the world has a lower than lower oxygen level than in our time (18% instead of 21 %), the mountains make for an interesting, but rather different biota than elsewhere. The upper altitudes are filled with archosaurs and archaic amphibians in cloud forests that get megamonsoons. The lower reaches in the rift that will eventually become the Newark supergroup, is a tropical rain forest with extremely unique mix of the clades.

Karoo:

The Karoo of what is modern South Africa also joins the mix as a temperate environment. A mix of plains, forests and everything between can be found here. Despite its name, this environment stretches all the way from one side of the Therapsids dominate southern hemisphere's terrestrial environment to the other, producing a swath of life filling the analogous role of Eurasia in our own biota.

Here, too, therapsids dominate, but the neoparieasaurs and the archosaurs have truly important additions. Vast herds migrating from along the latitudes are common here. Some that reach even from one end to the other in circular migratory paths.

Conan Doyle's Relica:

Lost worlds are a common theme. The Xenopermian is an extrapolation of the lost biota of the end Permian. Here, though, too a large single island has allowed populations of archaic forms to survive...and evolve in different directions than the mainland populations. Relica separated from the mainland during the early Permian allowing for pelycosaur grade synapsids and early parareptiles to evolve into strange, but plausible forms independent of the therapsids and more derived mainland clades. What happens when a sphenodont evolves for 60 million years independently of the therapsids and differently?

Life here is harsh and very similar in flora to Arctica, at least in analogous forms. Yet still very, very unique.

Ural Sea:

We jump back to the northern hemisphere for an environment that is like someone took the Red Sea, Tropical Forests, the coast of California and coast of Crimea and mixed them up in a massive way. Flanked in the east by the AnteUral Mountains and the West by the ProtoUral Mountains, the Ural Sea formed when the two mountain ranges that would form the future Ural Mountains caused the crust between them to buckle under rather than rise. Due to the weathering from the two mountain ranges, the sea is a very fertile and the lands, although narrow in the east-west direction, are very fertile as well, sporting a terrestrial fauna as diverse and teeming as the marine.

The reason that the Ural Sea was held to last, out of the north to south order, is that this is our first land to visit and the first

The XenoPermian Pareiasaurs, the pseudochelonids and their phylogeny, are our first graphic examples of the Xenopermian. They are excellent examples of one side of a megafaunal arms race!

Check back on 11/22!


Monday, September 19, 2011

This is actually pretty important...at least for us

A bit of a preface...

My family, as I have stated here before, has a very long tradition of being soldiers. My great grandfather, grandfather, father and brother all served. We served as a "family battalion" in the Civil War (Tennesseans fighting for the north). We were even exiled from Scotland for being Covenanters back in 1683 when we rose up against the then Dual Scottish/English crown (and like almost all glorious celtic rebellions rose heroically, fought like lions and were crushed thoroughly).

I've pondered that heritage more than a few times: why do we make such good soldiers? Why do we gravitate to the profession whether or not irregardless of our person wealth.

My wife and I are very different people. We often discuss it. One of the thing that came out is that I described that I truly enjoy being around other people...but I don't need to interact with others for me to be fine, even happy. My father was a true loner, but I don't see myself that way.

Then, a few days ago, a friend pointed this out:


IDK if I ought to be very, very worried or not. I'm conflicted whether or not to take a look under the hood as another friend put it. However, the only real benefit from doing so would be to see what I can do to raise my son better. (The fringe benefit is that I get my curiosity satisfied) That alone may be worth it.

IDK when regular postings will continue. I'd like to, but...Too Damned Busy.