WFS

Formation of sedimentary layers of white clay, Tamilnadu, India

Fossil site for wood fossils, Tamilnadu, India

Fossil site in Kerala, India

Fossil wood park maintained by geological survey of India at Tamilnadu

Cretaceous fossil sites india

Fossils in rack:-Cyad

Fossils in rack:-echiniderms

Fossils in rack:-Rastellum sp

Pre-historic seabed, Cretaceous period

Desert fossil discovery reveals surprises

December 17th, 2012

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A solar energy company planning a development in eastern Riverside County has discovered a rare Mojave Desert treasure-trove of Ice Age fossils, including a clutch of desert tortoise eggs believed to be the first found in California.

Paleontologists are buzzing about pieces of ivory from a mammoth tusk, the teeth of ancient horses and other indications of large vertebrate animals seldom found in California, they said. The first fossils of a sidewinder, desert horned lizard and desert kangaroo rat to be discovered in Riverside County also were located on the project site 13 miles southwest of Blythe, near the Arizona border.

“It’s quite a find,” said Casey Weaver, an engineering geologist with the California Energy Commission, which oversees licensing of the project. “It was very surprising, especially the number. We’ve never had a site that is so fossiliferous.”

The fossils were discovered as the developer, BrightSource Energy, prepared an environmental review for its application last year for the Rio Mesa solar complex. This week, the company submitted revised plans for how it will proceed with its project and extract what experts say is sure to be a valuable and informative cache of fossils underground.

Rio Mesa would have two solar plants on 4,000 acres. Each plant would have a 750-foot concrete tower surrounded by mirrors that focus the sun on a boiler to create steam and turn turbines. Together the facilities would generate about 500 megawatts of electricity, enough to serve 200,000 homes per year.

Most of the 800-plus fossils uncovered so far were fragments spread over eight miles on the Palo Verde Mesa, according to company documents submitted to the state.

“On a scientific level only, the finds are exciting in that it had been thought that the last Ice Age sediments laid down in the Blythe region were terraces of the Colorado River, but we can now say that animals and plants later remodeled the upper layers of these terrace sediments into a soil, and that hundreds of animals left their remains in that fossil soil,” said Joe Stewart, the project paleontologist from URS Corp.

The fossils were located in soil dating back about 14,000 years. Finding such treasures on the surface, where they had been subjected to the elements, means chances are good the fossils deeper down will be more intact and identifiable, said Eric Scott, curator of paleontology at the San Bernardino County Museum in Redlands, where the collection eventually will be curated.

Only a few paleontological records exist from the surrounding region, which makes this find noteworthy, he said. Scott was especially excited about the discovery of tortoise shell fragments and the pieces of eggs preserved inside a burrow.

“The tortoise shells are over the top. We have desert tortoise fossils from the Ice Age, but no shell fragments. That’s really significant. If you’re finding stuff that is that delicate and that rare and preserved in that good a condition, that supports arguments that other stuff down there will be really well preserved,” Scott said.

CLIMATE CHANGE CLUES

Pieces of large vertebrates were dragged by rodents into their burrows, including fragments of deer antlers, a pronghorn and what is believed to be a bighorn sheep, according to BrightSource documents filed with the state. Also found were fossils of rabbits, rodents, a badger and a coyote.

The discovery has given paleontologists an updated understanding of the prehistoric environment in that area. When combined with information about fossils found at Diamond Valley Lake, Joshua Tree, the La Brea Tar Pits, Arizona and Las Vegas, it may help provide some clues about climate change, Scott said.

The Pleistocene, from 40,000 to 11,000 years ago, was a time of dramatically shifting climates and temperatures, and produced abundant fossils that are often well-preserved and easy to date, experts said.

During that era, the Colorado River Valley was free of ice, and the lowlands were well-watered and vegetated from freshwater lakes and rivers, Scott said.

An area with lots of horses, mammoths, bison and camels would tell scientists of an abundance of food. Correlating that information with climate change over time can show how animals adapted and how they might change in the future, he said.

“We’ve moved past the idea of, ‘Wow, this is a mammoth, isn’t this cool.’ In order to understand how these animals were living and adapting to changing climate and conditions, you need not just a fossil, but samples of many different animals to tell you how the ecosystem worked,” Scott said.

It’s not known how deeply buried other Rio Mesa fossils might be, Scott said. Part of the site, which is owned by the Metropolitan Water District, was disturbed during World War II training exercises

FURTHER STUDY

In February, the Energy Commission asked BrightSource for additional excavation to determine where and how fossils are positioned beneath the surface, Weaver said.

BrightSource initially objected to the request because the work would cost the company time and money, according to documents. But this week, the company submitted a supplemental report laying out its plan for further study. The company will excavate 10 trenches about 10 feet deep and bore five deeper holes under supervision of a paleontologist.

Concern stems from the pedestals for the project’s mirrors. Driving the pylons into the ground will cause vibration that could damage any nearby fossils, the Energy Commission said. One of the conditions of certification will be training workers on what to do when they encounter fossils during excavation, the commission’s Weaver said.

BrightSource spokeswoman Kristen Hunter said the discovery won’t delay the project, which is expected to begin construction next year.

Paleontologist Stewart, of URS, said it is possible that the only fossils recovered will be “microvertebrates,” pieces such as lizard, snake and tortoise eggshell parts found by screening sediment.

“It is important to note these fossils found on the Rio Mesa site are not big flashy fossils that one would expect to see on display. Rather they are small fragments of skeletal elements,” he said. “We might not even see any of these fossils until we sort the concentrate with a microscope.”

The fossils are being stored temporarily at the URS lab in Pasadena. Once they are at the museum, the identities will be confirmed, samples will be numbered and labeled and they will be added to a digital database for use by other researchers, Scott said.

Pauline avibella

December 16th, 2012

Riffin

Fossils discovered of 425-million-year-old tiny shrimp-like creatures are of a species new to science, say experts.

Found in Herefordshire, the invertebrates were preserved by volcanic ash when the UK had a subtropical climate.

The fossils show the animals’ shells and soft tissues, such as eyes and limbs, the Leicester experts say.

Prof David Siveter said the species, named Pauline avibella in honour of his late wife, was a rare discovery.

‘Beautiful bird’

Our ancient planet

Planet Earth's geology - a coastal, rocky scene

At 425 million years old, these ostracodsoriginate from the earth’s Silurian period
It was when coral reefs first appeared and melting glacial formations meant a rise in sea levels
There was also a rapid spread of jawless fish, and the first known freshwater fish also emerged

“The find is important because it is one of only a handful preserving the fossilised soft-tissues of ostracods [type of crustacean],” he said.

“[The fossils] allow unparalleled insight into the ancient biology, community structure and evolution of animals.”

Avibella was chosen because it means beautiful bird, reflecting the fact the shell of these creatures looks like a wing to those that have studied it.

The genus name, Pauline, was a personal touch for Prof David Siveter.

“My wife gave me enormous support and it’s a tribute to her,” he said. “I can stand up at scientific meetings and talk about Pauline.”

The 1cm-long fossils were found in rocks at a site in Herefordshire, near the Welsh border.

‘Salami slicing’

The site has been known for about 10 years and once the University of Leicester team visited the area, they realised there was a “treasure trove” of ancient fossils.

The professor said the process of extracting the fossils from the limestone rock was like “salami slicing”.

Each specimen was ground down, with photographs taken at each stage, until they were completely destroyed.

The resulting 500 images were then stitched together using a computer to create “a virtual fossil”.

“What you have in the image is a real animal, warts and all,” said Prof Siveter.

“It might look strange but you’ve got relatives of these ostracods in your ponds, in lakes, rivers and the oceans.”

fossil bones with bug bites

December 11th, 2012

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Paleontologists have long been perplexed by dinosaur fossils with missing pieces – sets of teeth without a jaw bone, bones that are pitted and grooved, even bones that are half gone. Now a Brigham Young University study identifies a culprit: ancient insects that munched on dinosaur bones.

BYU professor Brooks Britt will publish his study of these dinosaur bone-eating bugs in the May 8 issue of the scientific journal Ichnos. Britt’s idea for this study came when he first noticed the unique markings on the bones as an undergraduate at BYU.

“As students we noticed these marks and thought it might be due to algae or insects and we started calling them ‘bug bites,’ just for fun,” Britt said.

Years later, current BYU student Anne Dangerfield also wondered about the markings and teamed up with Britt to investigate the cause. They studied insect traces on the 148-million-year-old remains of a Camptosaurus, a plant-eating specimen discovered in Medicine Bow, Wyo., in 1995.

“I knew this trace was something different because I had been looking at fossil termite traces all summer, so I knew we needed to check it out,” Dangerfield said.

Their analysis revealed that beetles, from the family entomologists call Dermestidae, left the markings on the Camptosaurus. Dermestid beetles still exist today and are typically brown or black, oval-shaped and feed on flesh, hair, skin or horns of carcasses.

Information about the beetle’s typical habitat reveals the climate at the time of the Camptosaurus’ death probably had 60-80 percent relative humidity and a temperature of 77-86 F. By comparison, the average yearly temperature in Medicine Bow is now 43.5 F.

When the dinosaur died near what is now Medicine Bow, the carcass was consumed by other insects. The beetles then infested the Camptosaurus within months of its death.

In addition to shedding light on Wyoming’s ancient climate, Dangerfield and Britt’s work shows dermestid beetles existed much earlier than previously thought. The traces on this Camptosaurus predate the oldest body fossils for dermestid beetles by 48 million years.

A pit excavated by the strong mandibles of dermestid beetle larvae while searching for soft, fat-soaked bone.

“This information gives us an idea of the environment during the Jurassic period and the evolution of insects,” Dangerfield said.

To analyze the markings on the bones, Britt went to his family dentist for molding materials, allowing Britt to more quickly create replicas of the bone traces to work with.

He took the castings back to BYU’s Earth Science Museum where he used an electron microscope to look at the mandible markings in the bone, analyzing eating patterns and the width between the teeth marks. Britt and Dangerfield compared the marks to information about the mandibles of moths, termites, mayflies and dermestid beetles – all known to consume bone – to determine the identity of the insect.

“Other people have thought they have seen dermestid beetle marks, or they have interpreted termite marks as dermestids, but this paper provides a guide to identifying insects from the bone traces,” Britt said.

Britt and Dangerfield continued their research by looking at more than 7,000 bones from various quarries and found that insect traces on dinosaur bones are quite common, but dermestid beetle traces were found only on the Camptosaurus skeleton from Medicine Bow.

“Dr. Britt’s work is really exciting and delves into unique aspects of paleobiology that few scientists have yet explored,” said Eric Roberts, an expert in dinosaur decomposition who teaches at South Africa’s University of the Witwatersrand. “Insects are among the most diverse and abundant organisms on the planet, yet we know next to nothing about the fossil record of insects because of their extremely limited preservation potential.”

Dangerfield’s undergraduate and graduate mentored research experience has impressed many potential employers. After finishing her master’s degree in August, she will assume a position with Exxon Mobile as an exploration oil and gas geologist.

“Whenever I show my resume, employers are impressed with the amount of undergraduate research I’ve done,” Dangerfield said.

Britt received his bachelor’s and master’s degrees at BYU and his Ph.D. at the University of Calgary and is an assistant professor. Rodney Scheetz, another author on the study, is the curator at BYU’s Earth Science Museum.

Note: This story has been adapted from a news release issued by Brigham Young University

Earliest evidence for reptiles

December 10th, 2012

Riffin

Newly discovered fossilised footprints provide the earliest evidence yet for the evolution of reptiles – a major event in the history of life. They are 315 million years old, making reptiles up to 3 million years older than previously thought.

The footprints were discovered by Dr Howard Falcon-Lang from the University of Bristol in sea cliffs, New Brunswick, Canada. The results of his study, undertaken with UK and Canadian colleagues, are published today in the Journal of the Geological Society of London.

Close up of a handprint showing five slender fingers, characteristic of reptiles. – Photo by Howard Falcon-Lang

Until now, the oldest reptile fossils were skeletons found in 1859 by William Dawson in Nova Scotia, and named Hylonomus lyelli after the nineteenth century geologist, Sir Charles Lyell.

Falcon-Lang said, “The new fossils were found in the same general region but at a level in the rock strata almost a kilometer below Dawson’s discovery. Consequently we can be confident the footprints are older than the skeletons. They were preserved when reptiles walked across the muddy bottom of a dry riverbed.

One of the metre-sized blocks of sandstone covered with fossil reptile tracks – Photo Credit: Howard Falcon-Lang

“The discovery was pure luck. As I walked along remote sea-cliffs at the end of a long day in the field, I passed a recent rock fall. One large slab of rock was covered with hundreds of fossil footprints! The sun was low in the sky and I probably wouldn’t have seen them if it hadn’t been for the shadows.”

Unlike their amphibian cousins, reptiles do not need to return to water to breed so they paved the way for the widespread colonization of dry land, and the establishment of diverse land-based ecosystems today. The difficult part of the study was proving that the footprints were actually those of reptiles and not just primitive amphibians.

“It was a bit like a crime scene investigation,” said Falcon-Lang, “we had found the footprints but who had made them?”

Professor Mike Benton, also of the University of Bristol, who co-authored the study, added, “There were only a few species capable of making prints like this around at the time so we came up with a short-list of suspects. However, the prints showed that the hands had five fingers and scales, sure evidence they were made by reptiles and not amphibians”.

The footprints prove that reptiles evolved even earlier than previously thought and existed in seasonally dry river-plains, a bit like those of northern Australia today. As the first pioneers of dry continental environments, they paved the way for the diverse terrestrial ecosystems that exist today.

Note: This story has been adapted from a news release issued by the University of Bristol

200-million-year-old fossil of leech found

December 9th, 2012

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Move over amber. When it comes to preserving soft-bodied animals through the ages, there’s a newcomer in town: fossilised leech “cocoons”.

Encased Vorticella-like fossil (Image: Benjamin Bomfleura, Hans Kerp, Thomas N. Taylor, Øjvind Moestrup, and Edith L. Taylor/PNAS)

The cocoons are secreted by many leech and worm species as mucous egg cases that harden and often fossilise. Almost two decades ago, Norwegian scientists found a perfectly preserved nematode worm embedded in the wall of a fossilised cocoon, but no one had investigated further.

So when Benjamin Bomfleur, a palaeobiologist at the University of Kansas, and his colleagues found fossil cocoons in 200-million-year-old rocks from the mountains of Antarctica, they took a closer look. They dissolved the rock with acid, leaving only the organic material – mostly leaf litter, but also 20 leech cocoons squashed flat by the pressure of aeons. One contained a perfectly preserved ciliated protozoan that appeared identical to modern single-celled “bell animals” (Vorticella) that live in ponds and streams.

The find is one of only a handful of fossilised ciliated protozoans. It suggests leech cocoons could be conservation traps in which, like amber, rarely fossilised creatures might be found.

Journal reference: PNAS, DOI: 10.1073/pnas.1218879109

Nyasasaurus parringtoni:Mysterious fossil identified

December 8th, 2012

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Researchers have found what could be the earliest known dinosaur to walk the earth lurking in the corridors of London’s Natural History Museum.

A mysterious fossil specimen that has been in the museum’s collection for decades has now been identified as most likely coming from a dinosaur that lived about 245 million years ago – 10 to 15 million years earlier than any previously discovered examples.

The creature was about the size of a Labrador dog and has been named Nyasasaurus parringtoni after southern Africa’s Lake Nyasa, today called Lake Malawi, and Cambridge University’s Rex Parrington, who collected the specimen at a site near the lake in the 1930s.

“It was a case of looking at the material with a fresh pair of eyes,” Paul Barrett from the Natural History Museum, who worked on the study, said. “This closes a gap in the fossil record and pushes back the existence of dinosaurs.”

The London fossil was studied by researchers in the 1950s but no conclusion

was reached and nothing was published, said Barrett. “It was a mystery what it was… It just became this mythical animal.”

Two features of the London fossil, together with a similar sample subsequently spotted at the Iziko South African Museum in Cape Town, are strong evidence that the animal belongs with the dinosaurs, the researchers said.

The bone tissues in the upper arm show marks of rapid growth, common in dinosaurs, and they also have a feature known as an elongated deltopectoral crest that anchored the upper arm muscles, a feature unique to dinosaurs.

“Although we only know Nyasasaurus from fossil fragments, the anatomy of its upper arm bone and hips have features that are unique to dinosaurs, making us confident we’re dealing with an animal very close to dinosaur origin,” said Barrett.

The researchers believe Nyasasaurus probably stood upright, was a metre tall at the hip, two to three metres long from head to tail, and weighed 20 to 60 kg.

A fossil of the right humerus (arm bone) of Nyasasaurus parringtoni

When it was alive, the world’s continents were joined in a vast landmass called Pangaea, and the area of Tanzania where the fossils were found would have been part of the southern Pangaea that included Africa, South America, Antarctica and Australia.

Theorists have long argued there should have been dinosaurs walking the earth in the Middle Triassic period, which ended about 237 million years ago, but until now the evidence has been ambiguous, said Sterling Nesbitt at the University of Washington in Seattle who led the study, published in the journal Biology Letters.

“If the newly named Nyasasaurus parringtoni is not the earliest dinosaur, then it is the closest relative found so far,” said Nesbitt.

“What’s really neat about this specimen is that it has a lot of history. Found in the 1930s, first described in the 1950s… Now 80 years later, we’re putting it all together.” (Reuters)

Nysasaurus parringtoni: world’s oldest dinosaur lived 245 million years ago ?

December 7th, 2012

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A creature about the size of a Labrador retriever with a 1.5-metre-long tail could be the earliest-known dinosaur to have walked the Earth, according to scientists.Research published Wednesday in the journal Biology Letters describes a set of fossilized bones from Tanzania that predates all other discoveries by 10 to 15 million years.

The Nysasaurus parringtoni, which stood upright, measured two to three metres from head to tail and weighed between 20 to 60 kilograms. It would have lived during the Middle Triassic period, about 245 million years ago. (Mark Witton/Natural History Museum

The new findings suggest that dinosaurs evolved earlier than previously thought — in the Middle rather than Late Triassic period.

The creature, which stood upright, measured two to three metres from head to tail and weighed between 20 to 60 kilograms. It would have lived during the Middle Triassic period, about 245 million years ago.

“If the newly named Nysasaurus parringtoni is not the earliest dinosaur, then it is the closest relative so far,” said Sterling Nesbitt, a paleontologist at the University of Washington.

The species was named in honour of Rex Parrington, who collected the specimens – an upper arm bone and six vertebrae — in the Ruhuhu Basin in southern Tanzania. Although the fossils were discovered in the 1930s, they had not been studied until now.

Earlier evolution

The bones reveal that N. parringtoni shared common characteristics with other dinosaurs and their close relatives, such as rapid growth.

“The bone tissue of Nysasaurus is exactly what we would expect for an animal at this position on the dinosaur family tree,” said University of California’s Sarah Warning, who did the bone analysis.

“It’s a very good example of a transitional fossil; the bone tissue shows that Nysasaurus grew about as fast as other primitive dinosaurs, but not as fast as later ones,” she said.

Nesbitt says the discovery has important implications if the species is indeed a dinosaur. “It establishes that dinosaurs likely evolved earlier than previously expected and refutes the idea that dinosaur diversity burst onto the scene in the Late Triassic, a burst of diversification unseen in any other groups at that time,” he said.

The Triassic period extended from about 250 million to 200 million years ago, following a so-called “Great Dying” event that triggered the extinction of more than 90 per cent of Earth’s species. The period saw the emergence of new creatures, including the first mammals.

The researchers suggest that dinosaurs were just another part of that gradual diversification.

The discovery is also noteworthy because the location of the fossils supports the hypothesis that dinosaurs originated in the southern parts of the prehistoric supercontinent of Pangaea. The remains of the oldest-known relative of the dinosaur, the Asilisaurus kongwe, were also discovered in southern Tanzania in 2007.

Racemization:New Test Adds to Scientists’ Understanding of Earth’s History

December 6th, 2012

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A new study co-authored by a University of Florida researcher provides the first direct chronological test of sequence stratigraphy, a powerful tool for exploring Earth’s natural resources.

The model allows geologists to better understand how sedimentary rocks are related to one another in time and space and predict what types of rocks are located in different areas. The information may help scientists more reliably interpret various aspects of Earth’s history such as long-term climate changes or extinction events, and also benefit companies searching for the best locations to drill for oil.

Shells and fragments found in sediments in the Po Plain, Italy, show the abundance and diversity of the area’s fossils. In a study published online Nov. 29, 2012, in Geology, researchers dated mollusks extracted from the sediment to verify key predictions of the sequence stratigraphy model, a powerful tool for interpreting Earth’s history and exploring for petroleum. (Credit: Daniele Scarponi, University of Bologna

The study recently published online in Geology uses extensive numerical dating of fossil shells to verify key predictions of the sequence stratigraphy model. Although used successfully for more than 30 years as a theoretical framework for interpreting and exploring rock bodies, the model had never been proven quantitatively by direct numerical dating.

“Paleontologists and geologists are well aware of the fact that you should not take the fossil record at face value because you will then see changes through time that may not be meaningful,” said study co-author Michal Kowalewski, a curator of invertebrate paleontology at the Florida Museum of Natural History on the UF campus. “However, by using dating to quantify how the resolution changes through time, we can improve quality control on our data and develop better strategies for reconstructing the history of life more accurately.”

In the study, researchers used racemization, a technique in which amino acid ratios are obtained to estimate the age of fossils from the most recent geological record. Relative age estimates were calibrated using radiocarbon to date about 250 mollusk shells extracted from cores drilled in the Po Plain in northern Italy. The technique, developed over the last 30 years, has made dating of large numbers of shells affordable and efficient, Kowalewski said.

Kowalewski is principal investigator on the National Science Foundation-funded project, a four-year study involving a team of scientists from the University of Bologna and Northern Arizona University.

“We were thrilled to learn that sedimentary rocks assemble through time exactly as predicted,” said Kowalewski, who recently relocated from Virginia Tech and is the Jon L. and Beverly A. Thompson Chair of Invertebrate Paleontology at the Florida Museum. “The results are not only a direct validation of the sequence stratigraphic model, but also provide us with direct numerical estimates of changes in the resolution of the fossil record as a function of relative changes in sea level.”

As the model predicted for the geological setting of the Po Plain, the sediments accumulated at an increasingly slower pace during initial phases of sea level rise, culminating with horizons that formed so slowly that shells from multiple millennia were mixed within the same sediment layers. Following the sea level rise, sediment was deposited at an increasingly faster pace.

“We are pretty confident that the primary driver of sea level changes in this time frame was climate, but that’s not always the case in the geological record,” Kowalewski said. ‘We can now provide a more informed constraint on timing of the most recent sea level rise in the northern Adriatic.”

Because the Po Plain contains young sediments dating to about the last 10,000 years, part of the cycle researchers tested includes changes occurring today, said Carlton Brett, a geology professor at the University of Cincinnati. As sea level rises quickly, sediment accumulates in bays and river mouths, leaving little sediment offshore, Brett said.

“I think what they’re doing is groundbreaking in the sense that they’re testing a model that is one of the most important models in sedimentary geology that has ever come down the pipe,” Brett said. “As one who uses that model a lot and makes those assumptions about why we are getting shell beds offshore, the fact that they have put numbers on the tests gives us very good confidence that we’re on the right track.”

The team plans to continue working in the Po Plain, a well-understood system that records the most recent millennia of the region’s geological history. The project can help researchers better understand human-induced changes because the Po Plain sediments document the fossil record of ecosystems that directly predate what many geologists refer to as the Anthropocene Epoch, the new geologic era of human modification of the natural world.

Study co-authors include Daniele Scarponi and Alessandro Amorosi of the University of Bologna, and Darell Kaufman of Northern Arizona University

Fossils and Genes Brought Together to Piece Together Evolutionary History

December 5th, 2012

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Paleontology, with its rocks and fossils, seems far removed from the world of developmental genetics, with its petri dishes and embryos. Whereas paleontology strives to determine “What happened in evolution?,” developmental genetics uses gene control in embryos to try to answer “How did it happen?” Combined, the two approaches can lead to remarkable insights that benefit both fields.

In the current issue of the Journal of Vertebrate Paleontology, Hans Thewissen, Ingalls-Brown Professor at Northeast Ohio Medical University (NEOMED), and his colleagues review recent studies that have used modern genetic techniques to shed light on fossils, and vice versa. “It is a very exciting time to be an evolutionary scientist. So many researchers are investigating evolution, either by finding new fossils or by figuring out the genes that underlie changes in evolution. Now it is possible to combine those two fields and go beyond what each field could have accomplished on its own,” said Dr. Thewissen.

Their review discusses the profound evolutionary changes that brought about some of the more spectacular animals of today and the past, including dolphins, whales, snakes, bats, elephants, and dinosaurs. For instance, although the transition from a four-legged ancestor to something with only two forelimbs, like a dolphin, or no limbs at all, like a snake, may seem like a big leap, transitional fossils have been discovered that bridge these gaps. Additionally, using developmental genetics, researchers have come to understand that these large changes in shape involved relatively small changes in the working of just of few genes.

Perhaps even more fascinating, recent research has discovered that similarly shaped organisms may not have experienced similar developmental changes in their past. Cetaceans (whales and dolphins) and snakes both lost limbs independently from their respective ancestors through evolution, but they did so in different ways. Snakes lost their forelimbs by basically getting rid of their neck region and leaving no room for forelimbs. During snake embryonic development, no limb buds form in that region of the body. Snakes do still develop hind limb buds as embryos, but the genes that control their growth have been knocked out through the course of evolution, so hind limbs do not develop (except for small stubs in some snakes like pythons). This demonstrates that different developmental mechanisms can be at work even in the evolutionary history of a single animal. Whales and dolphins lost their hind limbs in a process similar to that of snakes.

Dr. Thewissen says, “For me personally, as someone who has spent most of his life studying fossil whales, it is very exciting to be able to use information from the development of living mammals, and use it to teach me about how whale evolution happened, 50 million years ago.”

Scientists can even modify the genetic code of living animals to replicate changes that have been observed in the fossil record. As explained in the paper, it has been shown that heightened activity of a particular gene in mouse embryos causes their teeth to grow larger. A similar change occurred during the course of elephant evolution — early elephants had teeth less than an inch long, while modern elephants have teeth over a foot in length. The genetic changes that brought about this increase in size in elephants may have resembled the ones induced in lab mice.

This sort of cross-pollination of biological disciplines was once rare but is increasingly common. The paper was co-authored with Lisa Noelle Cooper, also of NEOMED, and Richard R. Behringer of the Department of Genetics at the University of Texas MD Anderson Cancer Center. Dr. Cooper said, “At a time when most of science is hyper-specialized, my hope is that the newest generations of scientists are able and unafraid to approach research questions using a variety of techniques.”

Holes in fossil bones reveal dinosaur activity

December 4th, 2012

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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.

holes in fossils

“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.”

Professor Seymour says following the results of this study, it’s likely that a simple measurement of foramen size could be used to evaluate maximum activity levels in other vertebrate animal groups, both living and fossils.

Note: This story has been adapted from a news release issued by the University of Adelaide