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.

Tuesday, August 30, 2011

Another Terrestrial Fish


One of the world's strangest animals – a unique fish that lives on land and can leap large distances despite having no legs – has a rich and complex social life, a new study has found.

The odd lifestyle of the Pacific leaping blenny (Alticus arnoldorum) has been detailed for the first time in research findings that throw new light on how animal life first evolved to colonise the land.

The Pacific leaping blenny is a marine fish yet is terrestrial in all aspects of its daily adult life, eking out a precarious existence in the intertidal zone of rocky shores in Micronesia, according to the study published in the journal Ethology , led by Dr Terry Ord, of the UNSW Evolution and Ecology Research Centre.

"This remarkable little fish seems to have made a highly successful transition across the water–land interface, although it is still needs to stay moist to enable it to breathe through its gills and skin," says Dr Ord, who is an evolutionary ecologist with a special interest in animal behaviour.

"Our study showed that life on land for a marine fish is heavily dependent on tide and temperature fluctuations, so much so that almost all activity is restricted to a brief period at mid-tide, the timing of which changes daily. During our field study on Guam we never saw one voluntary return to water. Indeed, they spend much of their time actively avoiding submersion by incoming waves, even when we tried to capture them for study.

"I can tell you they are very hard to catch and are extremely agile on land. They move quickly over complex rocky surfaces using a unique tail-twisting behaviour combined with expanded pectoral and tail fins that let them cling to almost any firm surface. To reach higher ground in a hurry, they can also twist their bodies and flick their tails to leap many times their own body length."

Working with Toni Hsieh, of Temple University in the US, Dr Ord found that adult blennies shelter in rock crevices at high and low tide, emerging at mid-tide to feed, breed and socialise in surprisingly complex ways – given their brief window of opportunity.

The researchers discovered that males are territorial and use complex visual displays to warn off rivals and attract mates. Females were seen aggressively defending feeding territory at the start of their breeding season, while males displayed a red-coloured fin and nodded their heads vigorously to attract females to their closely defended rock holes. The team filmed females inspecting these holes before entering with a chosen mate.

Little is known of their breeding and development of the young, but it seems that females lay their eggs in a chosen rock hole then play no further role in parenting, leaving the male to guard the eggs.

There's a good video here. The thing is damned agile. I was only aware of the mudskipper.

I Hate the Name Anthropocene

Anthropocene Mapping from Globaïa on Vimeo.


The Holocene is the same thing, really, and predates the goofy name. This is a nifty video though.

Nicked from James,

Wednesday, August 24, 2011

Juramaia sinensis: Earliest Known Eutherian Mammal?


A remarkably well-preserved fossil discovered in northeast China provides new information about the earliest ancestors of most of today's mammal species—the placental mammals. According to a paper published August 25 in the prestigious journal Nature, this fossil represents a new milestone in mammal evolution that was reached 35 million years earlier than previously thought, filling an important gap in the fossil record and helping to calibrate modern, DNA-based methods of dating the evolution.

The paper by a team of scientists led by Carnegie Museum of Natural History paleontologist Zhe-Xi Luo describes Juramaia sinensis, a small shrew-like mammal that lived in China 160 million years ago during the Jurassic period. Juramaia is the earliest known fossil of eutherians—the group that evolved to include all placental mammals, which provide nourishment to unborn young via a placenta. As the earliest known fossil ancestral to placental mammals, Juramaia provides fossil evidence of the date when eutherian mammals diverged from other mammals: metatherians (whose descendants include marsupials such as kangaroos) and monotremes (such as the platypus). As Luo explains, "Juramaia, from 160 million years ago, is either a great-grand-aunt, or a 'great-grandmother' of all placental mammals that are thriving today."

[...]

The fossil of Juramaia sinensis was discovered in the Liaoning Province in northeast China and examined in Beijing by Zhe-Xi Luo and his collaborators: Chong-Xi Yuan and Qiang Ji from the Chinese Academy of Geological Sciences, and Qing-Jin Meng from the Beijing Museum of Natural History, where the fossil is stored. The name Juramaia sinensis means "Jurassic mother from China." The fossil has an incomplete skull, part of the skeleton, and, remarkably, impressions of residual soft tissues such as hair. Most importantly, Juramaia's complete teeth and forepaw bones enable paleontologists to pin-point that it is closer to living placentals on the mammalian family tree than to the pouched marsupials, such as kangaroos.


less than no time...but could not resist.

Cool Video

Tempest Milky Way from Randy Halverson on Vimeo.


Brain cruncher is nearly done with me.

Wednesday, August 03, 2011

From the GLXP Summit


ARCA posted that from the team summit last july: we were at the Google's headquarters.


Team Puli posted this one.

Yes, I am at work. :(

Thursday, July 28, 2011

Wow

This blog has been rather neglected.

I am hoping about the middle of next month, I can get past what has been eating my brain, time and life to post once more. I may get something out tomorrow though.

Friday, July 08, 2011

Blood Vessels in Dinosaur Bones Suggest Endothermy

(caption:The y-axis is an index of the amount of blood flow through the foramen in relation to the body size of mammals (red), reptiles (blue) and dinosaurs (orange-red).)

New research from the University of Adelaide has added to the debate about whether dinosaurs were cold-blooded and sluggish or warm-blooded and active.

Professor Roger Seymour from the University's School of Earth & Environmental Sciences has applied the latest theories of human and animal anatomy and physiology to provide insight into the lives of dinosaurs. The results will be published this month in Proceedings B, the Proceedings of the Royal Society B (Biological Sciences), and can now be found online at: http://dx.doi.org/10.1098/rspb.2011.0968

Human thigh bones have tiny holes – known as the 'nutrient foramen' – on the shaft that supply blood to living bone cells inside. New research has shown that the size of those holes is related to the maximum rate that a person can be active during aerobic exercise. Professor Seymour has used this principle to evaluate the activity levels of dinosaurs.

"Far from being lifeless, bone cells have a relatively high metabolic rate and they therefore require a large blood supply to deliver oxygen. On the inside of the bone, the blood supply comes usually from a single artery and vein that pass through a hole on the shaft – the nutrient foramen," he says.

Professor Seymour wondered whether the size of the nutrient foramen might indicate how much blood was necessary to keep the bones in good repair. For example, highly active animals might cause more bone 'microfractures', requiring more frequent repairs by the bone cells and therefore a greater blood supply.

"My aim was to see whether we could use fossil bones of dinosaurs to indicate the level of bone metabolic rate and possibly extend it to the whole body's metabolic rate," he says. "One of the big controversies among paleobiologists is whether dinosaurs were cold-blooded and sluggish or warm-blooded and active. Could the size of the foramen be a possible gauge for dinosaur metabolic rate?"

Comparisons were made with the sizes of the holes in living mammals and reptiles, and their metabolic rates. Measuring mammals ranging from mice to elephants, and reptiles from lizards to crocodiles, one of Professor Seymour's Honours students, Sarah Smith, combed the collections of Australian museums, photographing and measuring hundreds of tiny holes in thigh bones.

"The results were unequivocal. The sizes of the holes were related closely to the maximum metabolic rates during peak movement in mammals and reptiles," Professor Seymour says. "The holes found in mammals were about 10 times larger than those in reptiles."

These holes were compared to those of fossil dinosaurs. Dr Don Henderson, Curator of Dinosaurs from the Royal Tyrrell Museum in Alberta, Canada, and Daniela Schwarz-Wings from the Museum für Naturkunde and Humboldt University Berlin, Germany, measured the holes in 10 species of dinosaur from five different groups, including bipedal and quadrupedal carnivores and herbivores, weighing 50kg to 20,000kg.

"On a relative comparison to eliminate the differences in body size, all of the dinosaurs had holes in their thigh bones larger than those of mammals," Professor Seymour says.

"The dinosaurs appeared to be even more active than the mammals. We certainly didn't expect to see that. These results provide additional weight to theories that dinosaurs were warm-blooded and highly active creatures, rather than cold-blooded and sluggish."

I don't have time to read the paper, but did they do modern birds?

Some original content coming soon, promise.

We both lovez and hatez the Beast Heads!

Friday, July 01, 2011

Wife Picture

Antarctica's Glacier Expansion Rate


A painstaking examination of the first direct and detailed climate record from the continental shelves surrounding Antarctica reveals that the last remnant of Antarctic vegetation existed in a tundra landscape on the continent's northern peninsula about 12 million years ago. The research, which was led by researchers at Rice University and Louisiana State University, appears online this week and will be featured on the cover of the July 12 issue of the Proceedings of the National Academy of Sciences.

The new study contains the most detailed reconstruction to date of the climatic history of the Antarctic Peninsula, which has warmed significantly in recent decades. The rapid decline of glaciers along the peninsula has led to widespread speculation about how the rest of the continent's ice sheets will react to rising global temperatures.

"The best way to predict future changes in the behavior of Antarctic ice sheets and their influence on climate is to understand their past," said Rice University marine geologist John Anderson, the study's lead author. The study paints the most detailed picture to date of how the Antarctic Peninsula first succumbed to ice during a prolonged period of global cooling.

In the warmest period in Earth's past 55 million years, Antarctica was ice-free and forested. The continent's vast ice sheets, which today contain more than two-thirds of Earth's freshwater, began forming about 38 million years ago. The Antarctic Peninsula, which juts farther north than the rest of the continent, was the last part of Antarctica to succumb to ice. It's also the part that has experienced the most dramatic warming in recent decades; its mean annual temperatures rose as much as six times faster than mean annual temperatures worldwide.


"There's a longstanding debate about how rapidly glaciation progressed in Antarctica," said Sophie Warny, a Louisiana State University geologist who specializes in palynology (the study of fossilized pollen and spores) and led the palynological reconstruction. "We found that the fossil record was unambiguous; glacial expansion in the Antarctic Peninsula was a long, gradual process that was influenced by atmospheric, tectonic and oceanographic changes."

Warny, her students and colleague Rosemary Askin were able to ascertain the exact species of plants that existed on the peninsula over the past 36 million years after a painstaking, three-year examination of thousands of individual grains of pollen that were preserved in muddy sediments beneath the sea floor just off the coast.

"The pollen record in the sedimentary layers was beautiful, both in its richness and depth," Warny said. "It allowed us to construct a detailed picture of the rapid decline of the forests during the late Eocene -- about 35 million years ago -- and the widespread glaciation that took place in the middle Miocene -- about 13 million years ago."


Solar Sand Sintering

Markus Kayser - Solar Sinter Project from Markus Kayser on Vimeo.



Friday, June 24, 2011

Dude! Little White Hunter


Or is this the ultimate in the therapsid v. archosaur wars?

He's closing in on two years old.

Monday, June 20, 2011

A Cretaceous Gomphodont?

This is not a new paper, but rather me digging through old papers looking for info for both the XenoPermian and the therocephalian post. Theoretically, there might have been dicynodonts and gomphodonts in the Australian Cretaceous. Ponder that!


AN ENIGMATIC (SYNAPSID?) TOOTH FROM THE EARLY CRETACEOUS OF NEW SOUTH WALES, AUSTRALIA

1. WILLIAM A. CLEMENS (a)
2. GREGORY P. WILSON (a)
3. RALPH E. MOLNAR (b)


a. Museum of Paleontology and Department of Integrative Biology, University of California Berkeley, California 94720-4785, bclemens@uclink4.berkeley.edu

b. Queensland Museum, P.O. Box 3300, South Brisbane QLD 4101, Australia, and Museum of Northern Arizona, Flagstaff, Arizona 86011

Abstract:

Largely fragmentary fossils from sites in New South Wales, Victoria, and Queensland, Australia document terrestrial and marine vertebrate faunas of Aptian–Albian age. The natural cast of a large tooth from the Griman Creek Formation, Lightning Ridge, New South Wales, records the presence of a hitherto unknown member of the fauna. Although reference to one of the groups of crocodyliforms that evolved complex, mammal-like postcanine teeth cannot be excluded, the fossil more likely represents a species of synapsid. In some respects it is similar to lower postcanines of traversodontids. Greater morphological similarities to upper molars of dryolestids make reference of this tooth to this group more likely. Current Mesozoic Laurasian and Gondwanan fossil records include mammals with cheek teeth of similar large size.



Link to paper in title.

Why Animals Don't Have IR Vision

On rare occasion, the light-sensing photoreceptor cells in the eye misfire and signal to the brain as if they have captured photons, when in reality they haven't. For years this phenomenon remained a mystery. Reporting in the June 10 issue of Science, neuroscientists at the Johns Hopkins University School of Medicine have discovered that a light-capturing pigment molecule in photoreceptors can be triggered by heat, as well, giving rise to these false alarms.

"A photon, the unit of light, is just energy, which, when captured by the pigment rhodopsin, most of the time causes the molecule to change shape, then triggering the cell to send an electrical signal to the brain to inform about light absorption," explains King-Wai Yau, Ph.D., professor of neuroscience at Johns Hopkins and member of its Center for Sensory Biology. "If rhodopsin can be triggered by light energy," says Yau, "it may also be occasionally triggered by other types of energy, such as heat, producing false alarms. These fake signals compromise our ability to see objects on a moonless night. So we tried to figure it out; namely, how the pigment is tripped by accident."

"Thermal energy is everywhere, as long as the temperature is above absolute zero," says neuroscience research associate Dong-Gen Luo, Ph.D. "The question is: How much heat energy would it take to trigger rhodopsin and enable it to fire off a signal, even without capturing light?" says Johns Hopkins Biochemistry, Cellular and Molecular Biology graduate student Wendy Yue.

For 30 years, the assumption was that heat could trigger a pigment molecule to send a false signal, but through a mechanism different from that of light, says Yau, because it seemed, based on theoretical calculations: that very little thermal energy was required compared to light energy.

But the theory, according to Yau, was based mainly on the pigment rhodopsin. However, rhodopsin is mainly responsible for seeing in dim light and is not the only pigment in the eye; other pigments are present in red-, green- and blue-sensitive cone photoreceptors that are used for color and bright-light vision. Although researchers are able to measure the false events of rhodopsin from a single rhodopsin-containing cell, a long-standing challenge has been to take measurements of the other pigments. "The electrical signal from a single cone pigment molecule is so small in a cone cell that it is simply not measurable," says Luo. "So we had to figure out a new way to measure these false signals from cone pigments."

By engineering a rod cell to make human red cone pigment, which is usually only found in cone cells, Yau's team was able to measure the electrical output from an individual cell and calculate this pigment's false signals by taking advantage of the large and detectable signals sent out from the cell.

As for blue cone pigment, "Nature did the experiment for us," says Yau. "In many amphibians, one type of rod cells called green rods naturally express a blue cone pigment, as do blue cones." So to determine whether heat can cause pigment cells to misfire, the team, working in the dark, first cooled the cells, and then slowly returned the cells to room temperature, measuring the electrical activity of the cells as they warmed up. They found that red-sensing pigment triggers false alarms most frequently, rhodopsin (bluish-green-sensing pigment) triggers falsely less frequently, and blue-sensing pigment does so even less.

"This validates the 60-year-old Barlow's hypothesis that suggested the longer wavelength the pigment senses—meaning the closer to the red end of the spectrum—the noisier it is," says Yau. And this finding led the team to develop and test a new theory: that heat can trigger pigments to misfire, by the same mechanism as light.

Pivotal to this theory is that visual pigment molecules are large, complex molecules containing many chemical bonds. And since each chemical bond has the potential to contain some small amount of thermal energy, the total amount of energy a pigment molecule could contain can, in theory, be enough to trigger the false alarm.

"For a long time, people assumed that light and heat had to trigger via different mechanisms, but now we think that both types of energy, in fact, trigger identical changes in the pigment molecules," says Yau. Moreover, since longer wavelength pigments have higher rates of false alarms, Yau says this may explain why animals never evolved to have infrared-sensing pigments.

"Apart from putting to rest a long-standing debate, it's a wake-up call for researchers to realize that biomolecules in general have more potential thermal energy than previously thought," says Luo.


Link in title.

Wednesday, June 15, 2011

The Geography of the XenoPermian

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...


No, I am not the artist. Scott is.

Just wait until the unveiling of Raven's Walrodont. Wow. Along with the suminid...they're stunning.

Comments?

Wednesday, June 08, 2011

Glaciations Influences Biodiversity More Than Climate


The study, published yesterday in the journal Ecology Letters, analyzed the species richness and the structure of their communities throughout the different regions of the European territory from the Ural Mountains to the Iberian Peninsula. The selection of this family of insects was motivated by their high dispersal ability and because their food sources (mainly cattle and sheep dung) are present throughout the continent.

Research by the Spanish National Research Council reveals that the large impacts occurred during the last ice age maintain their effects on the current distribution of dung beetles of the scarab family. The presence of these beetles in Europe seems to be more influenced by the climate of that glaciation than by the present one.

Scarabs are insects of tropical origin that cannot survive below 0 ° C mean annual temperature, "so it could be expected that their presence gradually decreases as temperatures drop down northwards " says the researcher from the National Museum of Natural Sciences, CSIC, Joaquín Hortal. However, the analysis of the relationship between the magnitude of climate change since the last glaciation and the distribution of scarabs evidences that these insects are not evenly distributed according to this gradient, but rather show two different patterns, one in the north and one in the south. Horton said: "The border defining the two areas is almost similar to the limit of 0 °C of mean annual temperature at the time of the last ice age." (See Figure 1)

Although scarab species richness is actually lower in the north that in the south, another two characteristics can be explained under the hypothesis of the influence of the last ice age.

The first one is based on the species present throughout Europe. Data show that all scarab species living in the northern territory above the border defined by the 0 ° C limit in the last glaciations are also present in the south, and there is no species exclusive to the northernmost area. According to Hortal, "this is an effect of the difficulty of adapting to cold climate that still exists, as the north does not hold unique species adapted to the cold."

This feature is consistent with the second observation, based on the age of the species present in each area. The study results show that the species that have been able to re-colonize the north are also those that have evolved most recently." Although the adaptation to cold climates started before the last glaciation, these species belong to the newer phylogenetic branches of the Scarabaeidae," says the researcher from CSIC.


Must. Read. Paper.

And have no time.

JH-7B? A New Stealth Fighter-Bomber?


Dewline also noticed it.

Thursday, June 02, 2011

Carbon Biomass Maps of Tropical Forests

Japanese Are Planning an Ikaros Follow-on


Japanese researchers are working on a solar-sail spacecraft with 10 times the surface area of the Ikaros testbed launched toward Venus last year, after achieving all of their technical objectives with the testbed.

This spacecraft will launch on a five-year mission instead of the six-month span allotted to Ikaros. Lofted as a piggyback payload with the Venus Climate Orbiter Akasuki on May 21, 2010, Ikaros passed Venus on Dec. 8.

Researchers hoped to demonstrate automatic sail deployment, power generation with thin-film solar cells on the sail surface, verification that the pressure of photons from the Sun caused the sail to accelerate, and guidance and navigation with the sail. The sail met its intended acceleration of 100 meters per second and veered off the ballistic trajectory it would have followed without the Sun’s pressure, says Yuichi Tsuda, an assistant professor in the Japan Aerospace Exploration Agency (JAXA) Space Exploration Center, in an English-language report on the experiment’s outcome.

The deployment and power generation were demonstrated early on. To control the 14 x 14-meter (46 x 46-ft.) spin-stabilized sail, the Ikaros team used a non-toxic “gas-liquid equilibrium thruster” for attitude control, and an attitude-detection system that combined a Sun sensor and Doppler measurements from the low-gain antenna.

To tilt the spin axis of the spacecraft, the team powered a liquid-crystal variable-reflectivity element mounted as a thin polyimide film around the edges of the sail off and on to throw the spinning sail off balance and tilt it as it spun. As it happened, the spacecraft required almost no fuel to keep its sail facing the Sun, even though it turned a full 180 deg. over the six months, according to Tsuda.


*sighs* This is actually a pretty important piece of tech going forward.

Another XenoPermian Teaser


Raven is making progress, too. I can't wait to show the whole piece. She's doing an astounding job.

These are Walrodonts.

Wednesday, June 01, 2011

Wooly-Columbian Mammoth Hybrid Found?

Mammoths were a diverse genus that roamed across Eurasia and North America during the Pleistocene era. In continental North America, at least two highly divergent species have long been recognized – woolly mammoths (Mammuthus primigenius) and Columbian mammoths (M. columbi). But new genetic evidence published in BioMed Central's open access journal Genome Biology suggests that these species may have been closely related enough to mate when they had the chance.

Remains of woolly mammoths have been found across the glacial tundra-steppe of Eurasia and northern North America, while the much physically larger Columbian mammoths inhabited the savannah environments of temperate southern and central North America. The differences between the species have long been considered as unique adaptations to the environments where they evolved. But by piecing together trace fragments of DNA from an 11 thousand year-old Columbian mammoth from Fairview, Utah, a team of Canadian, American and French researchers found that surprisingly the mitochondrial genome from this mammoth was nearly indiscernible from that of its northern woolly counterparts.

But the group does not suspect that this requires a re-write of North American mammoth evolution. "We think this individual may have been a woolly-Columbian hybrid," says Jacob Enk of the McMaster Ancient DNA Centre, the group that led the research. "Living African elephant species interbreed where their ranges adjoin, with males of the bigger species out-competing the smaller for mates. This results in mitochondrial genomes from the smaller species showing up in populations of the larger. Since woolly and Columbian ranges periodically overlapped in time and space, it's likely that they engaged in similar behaviour and left a similar genetic signal." The team goes on to suggest that interbreeding may explain some mammoth fossils that have intermediate physical characteristics, between woollies and Columbians, sometimes assigned to the species M. jeffersonii.

They do not rule out other explanations however, and note that the only way to know for sure whether their mammoth was a hybrid is to sequence nuclear DNA from it and other mammoths. For poorly-preserved remains like those of southern-ranging Columbians, this will be a challenge. But they expect that by exploiting new cutting-edge sequencing technologies, the nuclear genomes of these amazing animals are within reach.


...

Quantum Data Deletion May Have Cooling Effect?

Recent research by a team of physicists reveals a surprise at this fundamental level. ETH-Professor Renato Renner, and Vlatko Vedral of the Centre for Quantum Technologies at the National University of Singapore and the University of Oxford, UK, and their colleagues describe in the scientific journal Nature how the deletion of data, under certain conditions, can create a cooling effect instead of generating heat. The cooling effect appears when the strange quantum phenomenon of entanglement is invoked. Ultimately, it may be possible to harness this effect to cool supercomputers that have their performance held back by heat generation. «Achieving the control at the quantum level that would be required to implement this in supercomputers is a huge technological challenge, but it may not be impossible. We have seen enormous progress is quantum technologies over the past 20 years,» says Vedral. With the technology in quantum physics labs today, it should be possible to do a proof of principle experiment on a few bits of data.


hmmm. This almost sounds like a real world version of a Reynolds cryocomp.



Friday, May 27, 2011

A Crazy Dangerous Precedent: Seismologists Tried for Manslaughter In Italy

Earthquake prediction can be a grave, and faulty science, and in the case of Italian seismologists who are being tried for the manslaughter of the people who died in the 2009 L'Aquila quake, it can have legal consequences.

The group of seven, including six seismologists and a government official, reportedly didn't alert the public ahead of time of the risk of the L'Aquila earthquake, which occurred on April 6 of that year, killing around 300 people, according to the U.S. Geological Survey.

But most scientists would agree it's not their fault they couldn't predict the wrath of Mother Nature.

"We're not able to predict earthquakes very well at all," John Vidale, a Washington State seismologist and professor at the University of Washington, told LiveScience.


W

T

F?!

Strongly suggest if they get convicted that Italy's seismologists ought to...leave.

Thursday, May 26, 2011

Younger Dryas Impactor Hypothesis Crashes and Burns

It seemed like such an elegant answer to an age-old mystery: the disappearance of what are arguably North America’s first people. A speeding comet nearly 13,000 years ago was the culprit, the theory goes, spraying ice and rocks across the continent, killing the Clovis people and the mammoths they fed on, and plunging the region into a deep chill. The idea so captivated the public that three movies describing the catastrophe were produced.

But now, four years after the purportedly supportive evidence was reported, a host of scientific authorities systematically have made the case that the comet theory is “bogus.” Researchers from multiple scientific fields are calling the theory one of the most misguided ideas in the history of modern archaeology, which begs for an independent review so an accurate record is reflected in the literature.

“It is an impossible scenario,” says Mark Boslough, a physicist at Sandia Laboratory in Albuquerque, N.M., where he taps the world’s fastest computers for nuclear bomb experiments to study such impacts. His computations show the debris from such a comet couldn’t cover the proposed impact field. In March, a “requiem” for the theory even was published by a group that included leading specialists from archaeology to botany.

Yet, the scientists who described the alleged impact in a hallowed U.S. scientific journal refuse to consider the critics’ evidence — insisting they are correct, even though no one can replicate their work: the hallmark of credibility in the scientific world.

[...]

A new look at the comet claim suggests all of these phenomena may be in play, apparently creating a peculiar bond of desperation as the theory came under increasing attack. Indeed, the team’s established scientists are so wedded to the theory they have opted to ignore the fact their colleague “Allen West” isn’t exactly who he says he is.
West is Allen Whitt — who, in 2002, was fined by California and convicted for masquerading as a state-licensed geologist when he charged small-town officials fat fees for water studies. After completing probation in 2003 in San Bernardino County, he began work on the comet theory, legally adopting his new name in 2006 as he promoted it in a popular book. Only when questioned by this reporter last year did his co-authors learn his original identity and legal history. Since then, they have not disclosed it to the scientific community.
West’s history — and new concerns about study results he was integrally involved in — raise intriguing questions about the veracity of the comet claim. His background is likely to create more doubts about the theory. And the controversy — because it involves the politically sensitive issue of a climate shift — is potentially more broadly damaging, authorities suggest.

[...]

West has no formal appointment at an academic institution. He has said he obtained a doctorate from a Bible college, but he won’t describe it further. Firestone said West has told him he has no scientific doctorate but is self-taught. West’s Arizona attorney refers to him in writing as: “A retired geophysicist who has had a long and distinguished career.”

In the early 1990s, a new-age business West was involved in Sedona, Ariz., failed, and his well-drilling company went bankrupt. Then he ran afoul of California law in small Mojave Desert towns in a scheme with two other men, with court records saying they collected fees up to $39,500 for questionable groundwater reports.

He originally was charged with two felonies for falsely representing himself as a state-licensed geologist but agreed to a no contest plea to a single misdemeanor of false advertising as part of plea bargain in which state records say he was fined $4,500. Two other men in the scam also were sanctioned.

Acknowledging he made a mistake, West has sought to downplay the 9-year-old conviction. And last September, after his impact theory colleagues learned of it, he went back to court in Victorville, Calif., convincing a judge to void the old plea.

After earlier denying any impropriety with his Younger Dryas work, West declined a recent interview request. Last month, he wrote a letter charging it was “highly prejudicial and distorted” to bring up his legal past in the context of his current studies. He is a member of “a group of two dozen dedicated scientists performing cutting-edge, although controversial, research,” he wrote.


...

ouch.

Homo confisio strikes again? Or ought that be Homo audacia?

Wednesday, May 25, 2011

OSIRIS-REX Selected as Third New Frontiers Mission




NASA will launch a spacecraft to an asteroid in 2016 and use a robotic arm to pluck samples that could better explain our solar system's formation and how life began. The mission, called Origins-Spectral Interpretation-Resource Identification-Security-Regolith Explorer, or OSIRIS-REx, will be the first U.S. mission to carry samples from an asteroid back to Earth.

"This is a critical step in meeting the objectives outlined by President Obama to extend our reach beyond low-Earth orbit and explore into deep space," said NASA Administrator Charlie Bolden. "It’s robotic missions like these that will pave the way for future human space missions to an asteroid and other deep space destinations."



The first New Frontiers Mission was New Horizons which is en route to Pluto. The second is Juno which is due to be launched to Jupiter quite soon. NASA press release is here. Future Planetary Exploration has a nice summation of the proposal here.

Looks as Though Spirit Has Died But Not Opportunity


The MER Spirit seems to have not survived the winter. Opportunity continues to function.

Sadly, in some ways, that isn't a bad description of the space program at times. At least when I am bluest.

New Very Large Ordovician Anomalocaridid Discovered


aleontologists have discovered that a group of remarkable ancient sea creatures existed for much longer and grew to much larger sizes than previously thought, thanks to extraordinarily well-preserved fossils discovered in Morocco.

The creatures, known as anomalocaridids, were already thought to be the largest animals of the Cambrian period, known for the "Cambrian Explosion" that saw the sudden appearance of all the major animal groups and the establishment of complex ecosystems about 540 to 500 million years ago. Fossils from this period suggested these marine predators grew to be about two feet long. Until now, scientists also thought these strange invertebrates—which had long spiny head limbs presumably used to snag worms and other prey, and a circlet of plates around the mouth—died out at the end of the Cambrian.

Now a team led by former Yale researcher Peter Van Roy (now at Ghent University in Belgium) and Derek Briggs, director of the Yale Peabody Museum of Natural History, has discovered a giant fossilized anomalocaridid that measures one meter (more than three feet) in length. The anomalocaridid fossils reveal a series of blade like filaments in each segment across the animal's back, which scientists think might have functioned as gills.

In addition, the creature dates back to the Ordovician period, a time of intense biodiversification that followed the Cambrian, meaning these animals existed for 30 million years longer than previously realized.

"The anomalocaridids are one of the most iconic groups of Cambrian animals," Briggs said. "These giant invertebrate predators and scavengers have come to symbolize the unfamiliar morphologies displayed by organisms that branched off early from lineages leading to modern marine animals, and then went extinct. Now we know that they died out much more recently than we thought."


Note: There is a Devonian anomalocaridid already, Schinderhannes bartelsi, which already extended the clades' existence furter than the Ordovician already. This one IS the biggest by far though.

Monday, May 23, 2011

Kepler/Spitzer Telescopes Find, Confirm New Multi ExoPlanet System




A new planetary member of the Kepler-10 solar system was announced today. Using data from NASA's Spitzer Space Telescope, members of the Kepler science team confirmed a new planet, dubbed Kepler-10c.

The Kepler-10 star system is located about 560 light-years away near the Cygnus and Lyra constellations. The Kepler telescope has discovered two planets around this star. Kepler-10b is, to date, the smallest known rocky exoplanet, or planet outside our solar system (dark spot against yellow sun). This planet, which has a radius of 1.4 times that of Earth's, whips around its star every .8 days. Its discovery was announced in Jan. 2011.

Now, in May 2011, the Kepler team is announcing another member of the Kepler-10 family, called Kepler-10c. It's bigger than Kepler-10b with a radius of 2.2 times that of Earth's, and it orbits the star every 45 days. Both planets would be blistering hot worlds.

Kepler-10c was first identified by Kepler, and later validated using a combination of a computer simulation technique called "Blender," and NASA's Spitzer Space Telescope. Both of these methods are powerful ways to validate the Kepler planets that are too small and faraway for ground-based telescopes to confirm using the radial-velocity technique. The Kepler team says that a large fraction of their discoveries will be validated with both of these methods.

In the case of Kepler-10c, scientists can be 99.998 percent sure that the signal they detected is from an orbiting planet. Part of this confidence comes from the fact that Spitzer, an infrared observatory, saw a signal similar to what Kepler detected in visible light. If the signal were coming from something other than an orbiting planet -- for example an indistinguishable background pair of orbiting stars -- then scientists would expect to see different signals in visible and infrared light.


No time...but awesome.

Friday, May 20, 2011

Thursday, May 19, 2011

Mammalian Brain Expansion Due to Increased Sense of Smell?


Mammals first evolved their characteristic large brains to enable a stronger sense of smell, according to a new study published this week in the journal Science by paleontologists from The University of Texas at Austin, Carnegie Museum of Natural History and St. Mary's University in San Antonio.

This latest study is the first to use CT technology, similar to medical scanners, to reconstruct the brains of two of the earliest known mammal species, both from the Jurassic fossil beds of China. The 3D scans revealed that even these tiny, 190-million-year-old animals had developed brains larger than expected for specimens of their period, particularly in the brain area for smell.

Among living animals, mammals have the largest brains relative to body size. Scientists have proposed many explanations, but because fossil skulls of early mammals are extremely rare, have been reluctant to cut them open for closer study, thus destroying the fossils. Scientists have mostly relied on comparative studies of living mammals.

"We studied the outside features of these fossils for years," said Tim Rowe, professor in the Jackson School of Geosciences and director of the Vertebrate Paleontology Laboratory at The University of Texas at Austin, and lead author of the new study. "But until now, studying the brains meant destroying the fossils. With CT technology, we can have our cake and eat it, too."

According to the study, other factors leading to larger brains in early mammals included greater tactile sensitivity and enhanced motor coordination. Fossils of some of the earliest mammals, such as Hadrocodium, bore full coats of fur, explaining the need for enhanced tactile sensitivity.

Rowe's co-authors are Thomas E. Macrini, assistant professor of biological sciences at St. Mary's University in San Antonio, and Zhe-Xi Luo, curator and associate director for research and collections at the Carnegie Museum of Natural History.

Macrini conducted much of this research for his doctoral dissertation at The University of Texas at Austin, in which he scanned the heads of numerous fossil and living species to visualize the size and shape of their brains.

"This is the most comprehensive study yet undertaken using computed tomography to study the evolution of the mammalian skull," said Macrini. "And it is exciting to see these new insights emerging from years of intense labor."

Luo was involved in the discovery and research on the fossils for this study. When he first described the paper clip-sized mammal Hadrocodium ten years ago, he named it for its relatively large cranium despite its appearance so early in the mammalian lineage ("hadro" means "fullness" in Latin and "codium" means "head").


hm. Do we see a similar trend for gorgons? They had an awesome sense of smell.