Unless it’s just Sivapanthera linxiaensis.
Wednesday, December 31, 2008
Acinonyx jubatus: World’s Oldest Cheetah?
A primitive Late Pliocene cheetah, and evolution of the cheetah lineage. 2008. P. Christiansen and J. H. Mizak. PNAS. Published online before print Dec. 29, 2008
Unless it’s just Sivapanthera linxiaensis.
Read the story at National Geographic News.
Unless it’s just Sivapanthera linxiaensis.
Tuesday, December 30, 2008
7th Voyage of Sinbad Named To National Film Registry
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Competition Caused Neanderthal Extinction
Neanderthal Extinction by Competitive Exclusion. 2008. W.E. Banks, et al PLoS ONE 3(12): e3972.
The researchers used geographic locations of archaeological sites dated by radiocarbon, in conjunction with high-resolution simulations of past climates for specific periods to analyze relationships between the potential areas occupied by each human population. This modeling approach also allows the projection of the ecological footprint of one culture onto the environmental conditions of a later climatic phase―by comparing this projected prediction to the known archaeological sites dated to this later period, it is possible to determine if the ecological niche exploited by this human population remained the same, or if it contracted or expanded during that period of time.
Comparing these reconstructed areas for Neanderthals and anatomically modern humans during each of the climatic phases concerned, and by projecting each niche onto the subsequent climatic phases, Banks and colleagues determined that Neanderthals had the possibility to maintain their range across Europe during a period of less severe climatic conditions called Greenland Interstadial 8 (GI8).
However, the archaeological record shows that this did not occur, and Neanderthal disappearance occurs at a point when we see the geographic expansion of the ecological niche occupied by modern humans during GI8.
The researchers conclude that the Neanderthal populations that occupied what is now southern Spain were the last to survive because they were able to avoid direct competition with modern humans since the two populations exploited distinct territories during the cold climatic conditions of H4. They also point out that during this population event contact between Neanderthals and modern humans may have permitted cultural and genetic exchanges.
Neanderthal populations disappeared from Europe prior to the arrival of human populations around 40,000 years ago. Researchers have determined that their extinction was principally a result of competition with Cro-Magnon populations, rather than the consequences of climate change.From the press release:
The researchers used geographic locations of archaeological sites dated by radiocarbon, in conjunction with high-resolution simulations of past climates for specific periods to analyze relationships between the potential areas occupied by each human population. This modeling approach also allows the projection of the ecological footprint of one culture onto the environmental conditions of a later climatic phase―by comparing this projected prediction to the known archaeological sites dated to this later period, it is possible to determine if the ecological niche exploited by this human population remained the same, or if it contracted or expanded during that period of time.
Comparing these reconstructed areas for Neanderthals and anatomically modern humans during each of the climatic phases concerned, and by projecting each niche onto the subsequent climatic phases, Banks and colleagues determined that Neanderthals had the possibility to maintain their range across Europe during a period of less severe climatic conditions called Greenland Interstadial 8 (GI8).
However, the archaeological record shows that this did not occur, and Neanderthal disappearance occurs at a point when we see the geographic expansion of the ecological niche occupied by modern humans during GI8.
The researchers conclude that the Neanderthal populations that occupied what is now southern Spain were the last to survive because they were able to avoid direct competition with modern humans since the two populations exploited distinct territories during the cold climatic conditions of H4. They also point out that during this population event contact between Neanderthals and modern humans may have permitted cultural and genetic exchanges.
Monday, December 29, 2008
First Chinese Ceratopsid?
A dinosaur fossil field discovered this year in eastern China appears to be the largest in the world, a paleontologist told Xinhua on Monday.From Window of China:
More than 7,600 fossils have been discovered so far in Zhucheng City in eastern Shandong Province and the number is climbing, said Zhao Xijin from the IVPP, the paleontologist in charge of the project.
The city has a major field of large hadrosaurs, discovered in the 1960s by a Chinese oil expedition. More than 50 tons of fossils have been discovered since then. The world's largest hadrosaurs fossil was found here in the 1980s and exhibited in the local museum.
A new fossil site was found during another mining expedition in March in Longdu, Shunwang, Jiayue and Zhigou Towns. One field in Longdu is 300meters long by 10m wide and 5m deep. More than 3,000 fossils have been found at that site, among which new genera or species might be found, Zhao said.
A 2m skull of a large ceratopsian was found here, the first such discovery outside of North America, said Xu Xing, researcher from the IVPP.
In the 15 sub-fields, other new genera of ankylosaurs, tyrannosaurs and coelosaurs were also found, Xu said.
Mining had been suspended because of weather but would resume in the spring, Zhao said.
Research on the findings would be published at the end of next year, he said. A fossil park will be built in the region, local authorities said.
Thanks to David Evans for the lead.
2008 Top 10 Fossil Finds
Sunday, December 28, 2008
New Triassic Turtle: Chinlechelys tenertesta
A thin-shelled reptile from the Late Triassic of North America and the origin of the turtle shell . 2008. W. Joyce, et. al. Proc. Royal Soc. B 276: 1656
More on turtle orgins:
Abstract: A new, thin-shelled fossil from the Upper Triassic (Revueltian: Norian) Chinle Group of New Mexico, Chinlechelys tenertesta, is one of the most primitive known unambiguous members of the turtle stem lineage. The thin-shelled nature of the new turtle combined with its likely terrestrial habitat preference hint at taphonomic filters that basal turtles had to overcome before entering the fossil record.
Chinlechelys tenertesta possesses neck spines formed by multiple osteoderms, indicating that the earliest known turtles were covered with rows of dermal armour. More importantly, the primitive, vertically oriented dorsal ribs of the new turtle are only poorly associated with the overlying costal bones, indicating that these two structures are independent ossifications in basal turtles.
These novel observations lend support to the hypothesis that the turtle shell was originally a complex composite in which dermal armour fused with the endoskeletal ribs and vertebrae of an ancestral lineage instead of forming de novo. The critical shell elements (i.e. costals and neurals) are thus not simple outgrowths of the bone of the endoskeletal elements as has been hypothesized from some embryological observations.
Abstract: A new, thin-shelled fossil from the Upper Triassic (Revueltian: Norian) Chinle Group of New Mexico, Chinlechelys tenertesta, is one of the most primitive known unambiguous members of the turtle stem lineage. The thin-shelled nature of the new turtle combined with its likely terrestrial habitat preference hint at taphonomic filters that basal turtles had to overcome before entering the fossil record.
Chinlechelys tenertesta possesses neck spines formed by multiple osteoderms, indicating that the earliest known turtles were covered with rows of dermal armour. More importantly, the primitive, vertically oriented dorsal ribs of the new turtle are only poorly associated with the overlying costal bones, indicating that these two structures are independent ossifications in basal turtles.
These novel observations lend support to the hypothesis that the turtle shell was originally a complex composite in which dermal armour fused with the endoskeletal ribs and vertebrae of an ancestral lineage instead of forming de novo. The critical shell elements (i.e. costals and neurals) are thus not simple outgrowths of the bone of the endoskeletal elements as has been hypothesized from some embryological observations.
Born This Day: Alfred Sherwood Romer
Dec. 28, 1894 – Nov. 5, 1973
”Romer was director of the Museum of Comparative Zoology at Harvard University until his retirement in 1961 and was one the singularly most influential vertebrate paleontologists of the 20th Century. His work ranged over virtually every
conceivable subject within that field, although it was the osteology and taxonomy of the therapsids and other proto-mammals which was nearest his heart.
In addition to this work, Romer was acutely interested in the origin and initial adaptive radiation of tetrapods, and his work became the basis for a theory of tetrapod origins which was canon until the description of Acanthostega gunnari by Clack & Coates in the 1990s. Romer was ahead of his time in his defense of monophyly of Dinosauria though he did feel that Theropoda was not ancestral to birds.” link from EvoWiki.org
Romer’s book, Vertebrate Paleontology (1966), was for many years THE textbook on VP and is still well worth picking up. One of Romer’s students, Bob Carroll, wrote an updated version entitled, ‘Vertebrate Paleontology and Evolution’, in 1987. image
”Romer was director of the Museum of Comparative Zoology at Harvard University until his retirement in 1961 and was one the singularly most influential vertebrate paleontologists of the 20th Century. His work ranged over virtually every
conceivable subject within that field, although it was the osteology and taxonomy of the therapsids and other proto-mammals which was nearest his heart.In addition to this work, Romer was acutely interested in the origin and initial adaptive radiation of tetrapods, and his work became the basis for a theory of tetrapod origins which was canon until the description of Acanthostega gunnari by Clack & Coates in the 1990s. Romer was ahead of his time in his defense of monophyly of Dinosauria though he did feel that Theropoda was not ancestral to birds.” link from EvoWiki.org
Romer’s book, Vertebrate Paleontology (1966), was for many years THE textbook on VP and is still well worth picking up. One of Romer’s students, Bob Carroll, wrote an updated version entitled, ‘Vertebrate Paleontology and Evolution’, in 1987. image
Saturday, December 27, 2008
Aquaman in The Ocean of 1,000,000 B.C
From 1958; Aquaman © DC Comics
Click To Enlarge
Read the whole silly story over at Atomic Surgery.
Set Sail Today: HMS Beagle
In 1831, Charles Darwin set sail from Plymouth harbour on his voyage of scientific discovery aboard the HMS Beagle, a British Navy ship. The Captain Robert FitzRoy was sailing to the southern coast of South America in order to complete a government survey. Darwin had an unpaid position as the ship's naturalist, at age 22, just out of university.
Originally planned to be at sea for two years, the voyage lasted five years, making stops in Brazil, the Galapogos Islands, and New Zealand. From the observations he made and the specimens he collected on that voyage, Darwin developed his theory of biological evolution through natural selection, which he published 28 years after the Beagle left Plymouth.
The path of The HMS Beagle. © Pearson Education, Inc.
Click to enlarge.
Friday, December 26, 2008
El Bello Durmiente
El Bello Durmiente aka The Beautiful Dreamer (U.S. Title):
Wednesday, December 24, 2008
Evolving Giants
Two-phase increase in the maximum size of life over 3.5 billion years reflects biological innovation and environmental opportunity. 2008. J. Payne, et al. PNAS published online before print December 23, 2008. This is an open access article
Tales of Suspense #14 (1961) © Marvel Comics
"What is really interesting is that each of these 'steps' correlate with a time in life's history where there is innovation in the complexity of life, the first one being the eukaroytic cell and the second is the mulitcellularity of life," said Stempien.
During the first 1.5 billion years of the recorded history of life -- from about 3.5 billion to 2 billion years ago -- only bacteria-like fossils are found. Maximum size to which a bacteria cell can grow is severely limited. After the appearance of photosynthetic bacteria 3 billion years ago, the bacteria released oxygen making it possible for the evolution of a more complex cellular structure. In about two hundred million years, organisms went from cells not visible to the naked eye to macroscopic organisms, some about the size of a dime.
Life languished as single cells for another billion years or so, until just before the Precambrian-Cambrian transition about 540 million years ago, when atmospheric oxygen again increased notably reaching as much as 10 percent of its current concentration. Many scientists argue that the second increase in oxygen levels was a key prerequisite for evolution of yet more complex, multi-cellular (tissue-forming) life.
Once this new level of complexity was achieved, body size limits imposed on single-celled organisms were removed and larger organisms started appearing in the fossil record. Relatively quickly in evolutionary terms – in about one hundred million years – largest life forms transitioned from dime-size, single-celled forms to giant marine animals such as Ordovician cephalopods, tens of feet in length. Dinosaurs, which came much later, come to mind, although not mentioned in the PNAS paper.
Tales of Suspense #14 (1961) © Marvel Comics
Over 3.5 billion years the maximum body size of organisms increased by 16 orders of magnitude in two distinct bursts tied to the geological evolution of the planet.From the press release:
"What is really interesting is that each of these 'steps' correlate with a time in life's history where there is innovation in the complexity of life, the first one being the eukaroytic cell and the second is the mulitcellularity of life," said Stempien.
During the first 1.5 billion years of the recorded history of life -- from about 3.5 billion to 2 billion years ago -- only bacteria-like fossils are found. Maximum size to which a bacteria cell can grow is severely limited. After the appearance of photosynthetic bacteria 3 billion years ago, the bacteria released oxygen making it possible for the evolution of a more complex cellular structure. In about two hundred million years, organisms went from cells not visible to the naked eye to macroscopic organisms, some about the size of a dime.
Once this new level of complexity was achieved, body size limits imposed on single-celled organisms were removed and larger organisms started appearing in the fossil record. Relatively quickly in evolutionary terms – in about one hundred million years – largest life forms transitioned from dime-size, single-celled forms to giant marine animals such as Ordovician cephalopods, tens of feet in length. Dinosaurs, which came much later, come to mind, although not mentioned in the PNAS paper.
Note: The Palaeoblog will slow down for the next 10 days or so.
Have a happy holiday!
Have a happy holiday!
Tuesday, December 23, 2008
This Day In History: 1st Australopithecus africanus Skull Prepared
On this day in 1924 Raymond Dart finished preparing the first fossil skull of Australopithecus africanus. Known as the “Taung child”, he was only three years old at the time of death.
Click to download the PDF: Australopithecus africanus The Man-Ape of South Africa. 1925. Raymond Dart. Nature 115: 195.
Monday, December 22, 2008
Premiered This Day (1933): Son of Kong
Evolution by Max Fleischer
In addition to cartoons, the studio also made non-animated films such as “Evolution” (1923 [according to IMDB]). The film was Max Fleischer’s response to the high profile 1925 trial of John Scopes for teaching evolution in Tennessee.
“The trial was a fight between science and religion, and since science was involved Max [Fleischer] was once again completely captivated. He decided to make another long film that would present the scientific argument for Darwin’s theory. He contacted the American Museum of Natural History in New York and, with its cooperation and assistance, produced Darwin’s Theory of Evolution, a five-reel feature combining animation and live action. Once again, the man who had earned his reputation making people laugh had taken on a profoundly serious subject. The film was another surprise hit. Its first public screening was held in the Kaufman Theater of the American Museum of Natural History.”From Out of the Inkwell: Max Fleischer and the Animation Revolution by Richard Fleischer and Leonard Maltin.
Discovered This Day: Living Coelacanth
From Today In Science History:
In 1938, a coelacanth, a primitive fish thought extinct, was discovered. Marjorie Courtenay-Latimer was curator of the museum in the port town of East London, northeast of Cape Town, South Africa, and always interested in seeing unusual specimens. Hendrik Goosen, captain of the trawler Nerine, called her to see his catch of the day before, made at about 70-m depth, off the Chalumna River southwest of East London. She spotted an unusual 5-ft fish in his "trash" fish pile. It was pale mauvy-blue with iridescent silver markings. She sent a sketch to Dr J.L.B. Smith, a senior lecturer in chemistry from Rhodes University in Grahamstown for identification. It was hailed as the zoological discovery of the century and equated to finding a living dinosaur!
In 1938, a coelacanth, a primitive fish thought extinct, was discovered. Marjorie Courtenay-Latimer was curator of the museum in the port town of East London, northeast of Cape Town, South Africa, and always interested in seeing unusual specimens. Hendrik Goosen, captain of the trawler Nerine, called her to see his catch of the day before, made at about 70-m depth, off the Chalumna River southwest of East London. She spotted an unusual 5-ft fish in his "trash" fish pile. It was pale mauvy-blue with iridescent silver markings. She sent a sketch to Dr J.L.B. Smith, a senior lecturer in chemistry from Rhodes University in Grahamstown for identification. It was hailed as the zoological discovery of the century and equated to finding a living dinosaur!
“December 22, 1938, Captain Goosen and the Nerine put into East London harbour with the usual catch of sharks, rays, starfish and rat-tail fish. But there was one unusual fish amongst the catch that had been caught in about 70 meters, near the mouth of the Chalumna River. Once ashore Captain Goosen left word at the Museum that there were several specimens at the ship for Miss Latimer. At first she said that she was too busy because she was hard at work cleaning and articulating the fossil reptile bones collected from Tarkastad. But as it was so near Christmas time she decided to go and wish the crew a “Happy Christmas” and took a taxi to the docks. There, attracted by a blue fin amid the pile of sharks, she found a magnificent fish. She and her assistant put it in a bag and persuaded a reluctant taxi driver to take it to the museum in the boot of the car. It measured 150 cm and weighed 57.5 kg. From its hard bony scales with sharp, prickly spines and paired fins looking rather like legs, she knew that it must be some kind of primitive fish.Learn more about Latimeria chalumnae at the Australian Museum fish web page.
But her greatest problem was to preserve it until it could be identified. It was extremely hot, the fish, was too big to go into a bath and she could not find any organization willing to store it in a freezer. Although she was told by experts that it was only a type of rock cod and that she was making a fuss about nothing, she persisted in her attempts to save the fish for science. At first it was wrapped in cloths soaked in formalin but eventually, on the 26th, Mr. Center, a taxidermist, skinned it. Unfortunately the internal organs were thrown away. Marjorie went home disappointed and worried that she had not saved all the soft parts. What she had done, however, was to write immediately to her friend, JLB Smith, and send him her famous sketch of the strange fish.”
Miss Courtenay-Latimer's sketch of the first coelacanth which she posted to JLB Smith.
Died This Day: Ferdinand Vandiveer Hayden
Sept. 7, 1829 - Dec. 22, 1887
From Today In Science History
Hayden was an American geologist and explorer of the U.S. West.
After finishing a medical school training (1853), his early career began in paleontology for James Hall, collecting fossils in the Badlands and the Upper Missouri Valley. It is believed he made the first North American discovery of dinosaur remains (1854) during this expedition.
His work in the Great Plains and Rocky Mountains helped lay the foundation of the U.S. Geological Survey. Hayden is credited with having the Yellowstone geyser area declared the first national park (1872).
Image and more info on Hayden HERE.
From Today In Science History
Hayden was an American geologist and explorer of the U.S. West.
After finishing a medical school training (1853), his early career began in paleontology for James Hall, collecting fossils in the Badlands and the Upper Missouri Valley. It is believed he made the first North American discovery of dinosaur remains (1854) during this expedition. His work in the Great Plains and Rocky Mountains helped lay the foundation of the U.S. Geological Survey. Hayden is credited with having the Yellowstone geyser area declared the first national park (1872).
Image and more info on Hayden HERE.
Sunday, December 21, 2008
Born This Day: Hermann Joseph Muller
21 Dec. 21, 1890 – April 5, 1967
Click To EnlargeThe father of radiation genetics, Muller 
began his career with T.H. Morgan studying mutations in fruit flies. He was the first to increase the mutation rate using heat, later using 50 kilovolt X-rays to induce an even greater incidence of mutations. Muller was awarded the Nobel Prize for Physiology or Medicine in 1946
Muller long warned about needless exposures to radiation and their associated risks of cancer and heritable genetic effects. By the late 1940s, the nuclear weapons testing program had begun and Muller was a vocal critic of the Atomic Energy Commission's views on the hazards of worldwide fallout.
Click To Enlarge
began his career with T.H. Morgan studying mutations in fruit flies. He was the first to increase the mutation rate using heat, later using 50 kilovolt X-rays to induce an even greater incidence of mutations. Muller was awarded the Nobel Prize for Physiology or Medicine in 1946Muller long warned about needless exposures to radiation and their associated risks of cancer and heritable genetic effects. By the late 1940s, the nuclear weapons testing program had begun and Muller was a vocal critic of the Atomic Energy Commission's views on the hazards of worldwide fallout.
Born This Day: Sewell Wright
Dec. 21, 1889 – March 3, 1988.
From the ever eloquent Today In Science History:
Wright was an American geneticist who was one of the founders of modern theoretical population genetics. He researched the effects of inbreeding and crossbreeding with guinea pigs, and later on the effects of gene action on inherited characteristics. He adopted statistical techniques to develop evolutionary theory.
Wright is best known for his concept of genetic drift, called the Sewell Wright effect - that when small populations of a species are isolated, out of pure chance the few individuals who carry certain relatively rare genes may fail to transmit them. The genes may therefore disappear and their loss may lead to the emergence of new species, although natural selection has played no part in the process.
Check out genetic drift at The Biology Project at The University of Arizona.
Learn more about Wright HERE. Image from HERE
From the ever eloquent Today In Science History:
Wright was an American geneticist who was one of the founders of modern theoretical population genetics. He researched the effects of inbreeding and crossbreeding with guinea pigs, and later on the effects of gene action on inherited characteristics. He adopted statistical techniques to develop evolutionary theory. Wright is best known for his concept of genetic drift, called the Sewell Wright effect - that when small populations of a species are isolated, out of pure chance the few individuals who carry certain relatively rare genes may fail to transmit them. The genes may therefore disappear and their loss may lead to the emergence of new species, although natural selection has played no part in the process.
Check out genetic drift at The Biology Project at The University of Arizona.
Learn more about Wright HERE. Image from HERE
Saturday, December 20, 2008
Dino Sand Sculptures
These photos have been making the rounds so I’ll give you a link to the original source.
Artists are working on dinosaur sand sculptures at the
Sand Sculpting Australia exhibition "DinoStory" at Frankston Waterfront on December 19, 2008 in Melbourne, Australia. The exhibition, which will take 21 artists three weeks to construct, will be open to the public from December 26 to April 25.
Friday, December 19, 2008
New CMNH T.rex
Photo: Liz Russell/CMNH
The Cleveland Museum of Natural History officially unveils it's new T. rex cast tomorrow, Saturday Dec. 20. There will be lots of activities for the kids so come down and check out our latest addition.
Common Ancestor of Life Liked It Cool
Parallel adaptations to high temperatures in the Archaean eon. 2008. B. Boussau, et al. Nature 456: 942-945.
The study changes ideas of early life on Earth. "It is generally believed that LUCA was a heat-loving or hyperthermophilic organism. A bit like one of those weird organisms living in the hot vents along the continental ridges deep in the oceans today (above 90C°)," says Nicolas Lartillot, the study's co-author. "However, our data suggests that LUCA was actually sensitive to warmer temperatures and lived in a climate below 50 degrees."
The research team compared genetic information from modern organisms to characterize the ancient ancestor of all life on earth. "We identified common genetic traits between animals, plant, bacteria, and used them to create a tree of life with branches representing separate species. These all stemmed from the same trunk – LUCA, the genetic makeup that we then further characterized."
The group's findings are much more compatible with the theory of an early RNA world, where early life on Earth was composed of ribonucleic acid (RNA), rather than deoxyribonucleic acid (DNA).
However, RNA is particularly sensitive to heat and is unlikely to be stable in the hot temperatures of the early Earth. The data indicate that LUCA found a cooler micro-climate to develop, which helps resolve this paradox and shows that environmental micro domains played a critical role in the development of life on Earth.
It is only in a subsequent step that LUCA's descendants discovered the more thermostable DNA molecule, which they independently acquired (presumably from viruses), and used to replace the old and fragile RNA vehicle. This invention allowed them to move away from the small cool microclimate, evolved and diversify into a variety of sophisticated organisms that could tolerate heat.
Researchers have characterized the common ancestor of all life on earth, LUCA (Last Universal Common Ancestor) showing that the 3.8-billion-year-old organism was not the creature usually imagined.From the press release:
The study changes ideas of early life on Earth. "It is generally believed that LUCA was a heat-loving or hyperthermophilic organism. A bit like one of those weird organisms living in the hot vents along the continental ridges deep in the oceans today (above 90C°)," says Nicolas Lartillot, the study's co-author. "However, our data suggests that LUCA was actually sensitive to warmer temperatures and lived in a climate below 50 degrees."
The research team compared genetic information from modern organisms to characterize the ancient ancestor of all life on earth. "We identified common genetic traits between animals, plant, bacteria, and used them to create a tree of life with branches representing separate species. These all stemmed from the same trunk – LUCA, the genetic makeup that we then further characterized."
The group's findings are much more compatible with the theory of an early RNA world, where early life on Earth was composed of ribonucleic acid (RNA), rather than deoxyribonucleic acid (DNA).
However, RNA is particularly sensitive to heat and is unlikely to be stable in the hot temperatures of the early Earth. The data indicate that LUCA found a cooler micro-climate to develop, which helps resolve this paradox and shows that environmental micro domains played a critical role in the development of life on Earth.
It is only in a subsequent step that LUCA's descendants discovered the more thermostable DNA molecule, which they independently acquired (presumably from viruses), and used to replace the old and fragile RNA vehicle. This invention allowed them to move away from the small cool microclimate, evolved and diversify into a variety of sophisticated organisms that could tolerate heat.
Born This Day: Richard Leakey
From Today In Science History:
Leakey is a Kenyan physical anthropologist, paleontologist and second of three sons of noted anthropologists Louis Leakey and Mary Leakey. At an early age, he decided he wanted nothing to do with paleoanthropology and started a expedition business. In 1964, he led an expedition to a fossil site which sparked his interest in paleontology. Since then he has been responsible for extensive fossil finds of human ancestral forms in East Africa, including a Homo habilis skull found in 1972, and a Homo erectus skull found in 1975.
His discoveries showed that man's ancestors used tools, which shows intelligence, and lived in eastern Africa at least 3 million years ago - almost doubling the previously accepted age of human origins.
Learn more about The Leakey Foundation HERE.
Thursday, December 18, 2008
Avian Paternal Care Had Dinosaur Origin
Avian Paternal Care Had Dinosaur Origin. 2008. D.J. Varricchio et al. Science 5909: 1826 – 1828.
Citipati Photo: Mick Ellison/AMNH
From the press release:
Scientists came to that conclusion after examining the clutch size and internal bone structures in Troodon, Oviraptor and Citipati dinosaurs. Previous studies had found that the dinosaurs shared several reproductive features with living birds. They both produced asymmetric eggs with nearly identical eggshell, for example. Adult dinosaurs were also found on top of clutches, possibly brooding the eggs.
To further test the theory, the paleontologists examined the bones of adult dinosaurs found on top of clutches in Montana and Mongolia. None of the bones contained tissue normally associated with egg-laying females. Female birds store minerals for egg-laying as extra tissue in the inside of their hollow limb bones.
Abstract: The repeated discovery of adult dinosaurs in close association with egg clutches leads to speculation over the type and extent of care exhibited by these extinct animals for their eggs and young. To assess parental care in Cretaceous troodontid and oviraptorid dinosaurs, we examined clutch volume and the bone histology of brooding adults. In comparison to four archosaur care regressions, the relatively large clutch volumes of Troodon, Oviraptor, and Citipati scale most closely with a bird-paternal care model. Clutch-associated adults lack the maternal and reproductively associated histologic features common to extant archosaurs. Large clutch volumes and a suite of reproductive features shared only with birds favor paternal care, possibly within a polygamous mating system. Paternal care in both troodontids and oviraptorids indicates that this care system evolved before the emergence of birds and represents birds' ancestral condition. In extant birds and over most adult sizes, paternal and biparental care correspond to the largest and smallest relative clutch volumes, respectively.
Citipati Photo: Mick Ellison/AMNH
A new study suggests that males from three types of dinosaurs were sole care givers for their mate's eggs. They may even have had multiple mates and watched all their eggs at once.The dinosaurs in the study were close ancestors of birds, and their fossils were found on top of unusually large clutches. It’s possible that the males mated with several females who laid their eggs in one large clutch. When the females left, the males incubated and protected the eggs on their own.
Scientists came to that conclusion after examining the clutch size and internal bone structures in Troodon, Oviraptor and Citipati dinosaurs. Previous studies had found that the dinosaurs shared several reproductive features with living birds. They both produced asymmetric eggs with nearly identical eggshell, for example. Adult dinosaurs were also found on top of clutches, possibly brooding the eggs.
To further test the theory, the paleontologists examined the bones of adult dinosaurs found on top of clutches in Montana and Mongolia. None of the bones contained tissue normally associated with egg-laying females. Female birds store minerals for egg-laying as extra tissue in the inside of their hollow limb bones.
Abstract: The repeated discovery of adult dinosaurs in close association with egg clutches leads to speculation over the type and extent of care exhibited by these extinct animals for their eggs and young. To assess parental care in Cretaceous troodontid and oviraptorid dinosaurs, we examined clutch volume and the bone histology of brooding adults. In comparison to four archosaur care regressions, the relatively large clutch volumes of Troodon, Oviraptor, and Citipati scale most closely with a bird-paternal care model. Clutch-associated adults lack the maternal and reproductively associated histologic features common to extant archosaurs. Large clutch volumes and a suite of reproductive features shared only with birds favor paternal care, possibly within a polygamous mating system. Paternal care in both troodontids and oviraptorids indicates that this care system evolved before the emergence of birds and represents birds' ancestral condition. In extant birds and over most adult sizes, paternal and biparental care correspond to the largest and smallest relative clutch volumes, respectively.
Died This Day: Sir Richard Owen
July 20, 1804 – Dec. 18, 1892
From Today In Science History:
Owen was an English anatomist and paleontologist who is remembered for his contributions to the study of fossil animals and for his strong opposition to the views of Charles Darwin.
He coined the word "Dinosaur" meaning "terrible reptile" (1842). Owen synthesized French anatomical work, especially from Cuvier and Geoffroy, with German transcendental anatomy. He gave us many of the terms still used today in anatomy and evolutionary biology, including "homology". In 1856, he was appointed Superintendent of the British Museum (Natural History).
From Today In Science History:
Owen was an English anatomist and paleontologist who is remembered for his contributions to the study of fossil animals and for his strong opposition to the views of Charles Darwin.He coined the word "Dinosaur" meaning "terrible reptile" (1842). Owen synthesized French anatomical work, especially from Cuvier and Geoffroy, with German transcendental anatomy. He gave us many of the terms still used today in anatomy and evolutionary biology, including "homology". In 1856, he was appointed Superintendent of the British Museum (Natural History).
Austroraptor cabazai: New Gondwanan Dromaeosaurid
A bizarre Cretaceous theropod dinosaur from Patagonia and the evolution of Gondwanan dromaeosaurids. 2008. F. Novas, et a. Proc. Royal Soc. B. Publishedonline, December 16, 2008.
Click To EnlargeIts long and low snout bears numerous, small-sized conical teeth, a condition resembling spinosaurid theropods. Its short forearms depart from the characteristically long-armed condition of all dromaeosaurids and their close avian relatives.
The new discovery amplifies the range of morphological disparity among unenlagiines, demonstrating that by the end of the Cretaceous this clade included large, short-armed forms alongside crow-sized, long-armed, possibly flying representatives.
The new dinosaur is the youngest record of dromaeosaurids from Gondwana and represents a previously unrecognized lineage of large predators in Late Cretaceous dinosaur faunas mainly dominated by abelisaurid theropods.
The National Geographic story.
The giant raptor, Austroraptor cabazai, found in Argentina, measured 5 to 6.5 meters long, making it one of the largest raptors to roam Earth 70 million years ago.Abstract: Fossils of a predatory dinosaur provide novel information about the evolution of unenlagiines, a poorly known group of dromaeosaurid theropods from Gondwana. The new dinosaur is the largest dromaeosaurid yet discovered in the Southern Hemisphere and depicts bizarre cranial and postcranial features.
Click To Enlarge
The new discovery amplifies the range of morphological disparity among unenlagiines, demonstrating that by the end of the Cretaceous this clade included large, short-armed forms alongside crow-sized, long-armed, possibly flying representatives.
The National Geographic story.
Died This Day: Jean-Baptiste de Monet, Chevalier de Lamarck
Aug.1, 1744 – Dec. 18, 1829
From Today in Science History:
Pioneer French biologist who is noted for his speculations about the evolution of living things,
particularly his theory that acquired traits are inheritable (such as giraffes who, he said, through stretching to reach tall trees, make their necks longer, and then pass on longer necks to their offspring.) This Lamarckism idea is controverted by Darwinian theory.
He published a flora of France (1778) and a system of classification for invertebrate animals, published in his Histoire naturelle des animaux sans vertebres (7 vols, 1815-22). In 1809 Lamarck published his theory of evolution (in Philosophie zoologique). Lamarck's speculations about the physical and natural world found little favour among his contemporaries and he died blind and in poverty.
From info on Lamarck from The Victorian Web.
From Today in Science History:
Pioneer French biologist who is noted for his speculations about the evolution of living things,
particularly his theory that acquired traits are inheritable (such as giraffes who, he said, through stretching to reach tall trees, make their necks longer, and then pass on longer necks to their offspring.) This Lamarckism idea is controverted by Darwinian theory.He published a flora of France (1778) and a system of classification for invertebrate animals, published in his Histoire naturelle des animaux sans vertebres (7 vols, 1815-22). In 1809 Lamarck published his theory of evolution (in Philosophie zoologique). Lamarck's speculations about the physical and natural world found little favour among his contemporaries and he died blind and in poverty.
From info on Lamarck from The Victorian Web.
Died This Day: Theodosius Dobzhansky
Jan. 25, 1900 – Dec. 18, 1975
From Today In Science History:
Dobzhansky was an Ukrainian-American geneticist and evolutionist whose work had a major influence on 20th-century thought and research on genetics and evolutionary theory. He made the first significant synthesis of Charles Darwin's theory of evolution with Gregor Mendel's theory of genetics in his book Genetics and the Origin of Species (1937).
From 1918 his research gave experimental evidence that genes could vary far more than geneticists had previously believed. Thus, successful species tend to have a wide variety of genes that, while redundant in its present environment, do provide a species as a whole with genetic diversity. Such diversity enables the species to adapt effectively to changes in the surrounding environment - the basis for modern evolutionary theory.
From Today In Science History:
Dobzhansky was an Ukrainian-American geneticist and evolutionist whose work had a major influence on 20th-century thought and research on genetics and evolutionary theory. He made the first significant synthesis of Charles Darwin's theory of evolution with Gregor Mendel's theory of genetics in his book Genetics and the Origin of Species (1937). From 1918 his research gave experimental evidence that genes could vary far more than geneticists had previously believed. Thus, successful species tend to have a wide variety of genes that, while redundant in its present environment, do provide a species as a whole with genetic diversity. Such diversity enables the species to adapt effectively to changes in the surrounding environment - the basis for modern evolutionary theory.
Wednesday, December 17, 2008
World's Oldest Spider Web Found
Spot the web.
An amateur fossil-hunter searching the beaches of England's south coast discovered the web’s tiny twisted threads encased in an ancient piece of amber nearly two years ago.
Paleobiologist Martin Brasier said the 140-million-year-old web is proof that arachnids have been around since the time of the dinosaur. He noted that the threads were linked to each other in the same nearly circular pattern seen in gardens throughout the world.
A microscope revealed miniscule threads about 1/20th of an inch long among bits of burnt sap and fossilized vegetable matter.
However, spider experts believe the webs were developed even earlier, despite the fact they rarely leave any trace.
Born This Day: Willard F. Libby
Dec 17, 1908 – Sept. 8, 1980
Libby was an American chemist who won the Nobel Prize for Chemistry in 1960 for developing the technique of carbon-14 dating. Duing WWII he worked on the Manhattan Project. Libby was responsible for the gaseous diffusion separation and enrichment of the Uranium-235 which was used in the atomic bomb.
On 18 May 1952, he determined that the age of Stonehenge was 1848 BC, based on analysis of radioisotopes in charcoal. He also discovered that tritium could be used for dating water.
Libby was an American chemist who won the Nobel Prize for Chemistry in 1960 for developing the technique of carbon-14 dating. Duing WWII he worked on the Manhattan Project. Libby was responsible for the gaseous diffusion separation and enrichment of the Uranium-235 which was used in the atomic bomb.On 18 May 1952, he determined that the age of Stonehenge was 1848 BC, based on analysis of radioisotopes in charcoal. He also discovered that tritium could be used for dating water.
Tuesday, December 16, 2008
Geof Darrow's Dinos
Click to enlarge. © DC Comics
To my eye Geof’s doing a riff on this classic “Calvin & Hobbes” strip.
Monday, December 15, 2008
Palaeoblog's 2008 Christmas Shopping Guide
Once again the Palaeoblog presents some gift suggestions for those last minute shoppers. This is by no means meant to be comprehensive, and in many cases I’ve posted about the items below at some time in the past.
It's a shorter list than last year, but many of those suggestions are still valid, so check that list out too. And now, in no particular order:
For the serious dinosaur enthusiast who has good grasp of anatomical terminology, the second edition of The Dinosauria is the book for them. No colour pictures but it is the definitive word on the subject as of a few years ago. Bright, young, hope-to-be palaeontologists might like to have if on their shelf as well.
St. John is still considered to be the quintessential painter for the works of Edgar Rice Burroughs. Prehistoric critters turn up in many of his paintings.Like This? Then you’ll like this.
For the anatomy student.
A good book made great by Doug Henderson's drawings. Like This? Then you’ll like this.
Encyclopedia Prehistorica By Robert Sabuda and Matthew Reinhart. These three pop-up books are now available in a designer ‘shipping box’. If you’ve not picked them up yet this will make a great gift for yourself.
By John Long and Peter Schouten
Don’t let the 1950’s cover homage throw you off. This new book focus’s on Bill’s most recent museum mural paintings. Like this? Then you’ll like this.
By John Pattona and Lita Judge. Lita is a former Centrosaurus bone bed volunteer who has made quite a name for herself as an artist.
By Alan Turner and Mauricio Anton. Like This? Then you’ll like this.
By Dennis Nolan – for all the kids
Is it just me or are there fewer good science documentaries made each year? So, why not go with the perennial favourites? This special edition of The Lost world gives you both the silent (1925) and Michael Rennie/Pat Boone (1960) versions of Sir Arthur Conan Doyle’s classic story, all for a cheap price. Like This? Then you’ll like this.
Papo dinosaurs. This toy company from France has a small, but well done, line of dinosaurs. Most better museums and toy stores have them in stock. I bought mine at the ROM in Toronto. Like This? Then you’ll like this.
Movie Poster.com and EBay are good places to pick up both original and reproduction movie posters. Like This? Then you’ll like this.
By Neil Shubin. Perhaps the best reviewed science book of the year. Definitely worth a read, but this book by Carl Zimmer still holds up.
Probably my favourite book of the year - at least the one I've been waiting the longest for! I'll have a review of it up soon. Like This? Then you’ll like this.
Mark Schultz returns to Xenozoic Tales with this fine print from Flesk Publications. Get it Here
Remember that Mark has a new colour dinosaur print available exclusively from the Palaeoblog. For more info go to this previous posting.
Why not pick up an out of print classic for the palaeo-historian on your list? If you don't have a bricks and mortar store nearby then an on-line dealer like ABE.com can help you out.
Thomas Huxley, 'nuff said. One of the four people from the past that I'd have at my imaginary dinner party. Like This? Then you’ll like this.
Take your family to your local museum. Better yet, buy them a membership.
One of the first and still the best recounting of the history of the Earth in cartoon format. Still relevant and fun after all these years. Like This? Then you’ll like this.
- The Palaeontological Society (US) (publishes the Journal of Paleontology monthly)
- The Palaeontological Association (UK) (publishes Palaeontology monthly)
Each membership includes a one year subscription to the society’s professional journal. It’s a great gift for a young professional who might not have the money in hand to sign themselves up, or for a high school student looking to study palaeontology at university.
Finally, (I’m allowed one plug for myself), join me for two weeks digging up dinosaurs in the Gobi Desert next August. Details at Nomadic Expeditions
It's a shorter list than last year, but many of those suggestions are still valid, so check that list out too. And now, in no particular order:
St. John is still considered to be the quintessential painter for the works of Edgar Rice Burroughs. Prehistoric critters turn up in many of his paintings.Like This? Then you’ll like this.
For the anatomy student.
By John Long and Peter Schouten
By Alan Turner and Mauricio Anton. Like This? Then you’ll like this.
By Dennis Nolan – for all the kids
Remember that Mark has a new colour dinosaur print available exclusively from the Palaeoblog. For more info go to this previous posting.
Written by Robert Kanigher, Art by Ross Andru & Mike Esposito.
Over 500 pages of classic adventures are included in this value-priced volume collecting one of the most unusual series ever from DC Comics. Soldiers vs. dinosaurs -- what's not to love? Like This? Then you’ll like this.
Join A Professional Society
Such as:
-- the Society of Vertebrate Paleontology (publishes the Journal of Vertebrate Paleontology quarterly)
Such as:
- The Palaeontological Society (US) (publishes the Journal of Paleontology monthly)
- The Palaeontological Association (UK) (publishes Palaeontology monthly)
Each membership includes a one year subscription to the society’s professional journal. It’s a great gift for a young professional who might not have the money in hand to sign themselves up, or for a high school student looking to study palaeontology at university.
GO ON A DINOSAUR DIG!
Finally, (I’m allowed one plug for myself), join me for two weeks digging up dinosaurs in the Gobi Desert next August. Details at Nomadic Expeditions
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