Tuesday, December 28, 2010
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
Monday, December 27, 2010
Scientists have used statistical analyses to determine that for 90 species of theropod dinosaurs, especially the most bird-like dinosaurs—known as coelurosaurs—plant eating was a common way of life.Unlike Tyrannosaurus rex with its bone-crunching teeth, many coelurosaurian dinosaurs have peg-like teeth at the front of the mouth or no teeth at all so determining their diet has been a challenge.
Fortunately a small percentage of these species also preserve clear-cut evidence of diet with their skeletal remains. Fossilized dinosaur dung, stomach contents, tooth marks, the presence of stones within the stomach that serve as a gastric mill for digesting vegetation, and even two dinosaur species preserved locked in the throes of combat all provide a direct window on diet. After collecting dietary data for almost 100 coelurosaur species, the researchers found that almost two dozen anatomical features could be linked to direct evidence of herbivory including a toothless beak.
Because plant eating was found to be so widespread in Coelurosauria, the hypercarnivorous habits of T. rex and other meat eating coelurosaurs like Velociraptor should be viewed more as the exception than the rule.
The resesrchers also found that a toothless beak only evolved in lineages known to have had a gastric mill for grinding plants. In lineages where a gastric mill is not yet known, such as the bizarre, sickle-clawed therizinosaurs, the species retain teeth at the back of the mouth for shredding plant material.
Because ceolurosaurian dinosaurs include the closest extinct relatives of birds, understanding their biology is also extremely important to understanding how, why, and under what conditions birds evolved and first took flight. link.
Dear Field Museum Press People: Surely the FM has put out a press release since last August. I'd suggest updating your press page, especially when you provide links to out of date sites.
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.
Thursday, December 23, 2010
New fossil site in China shows long recovery of life from the largest extinction in Earth’s history.
Some 250 million years ago, at the end of the Permian, life was all but wiped out during a sustained period of massive volcanic eruption and devastating global warming. Only one in ten species survived, and these formed the basis for the recovery of life in the subsequent time period, called the Triassic. The new fossil site – at Luoping in Yunnan Province – provides a new window on that recovery, and indicates that it took about 10 million years for a fully-functioning ecosystem to develop.
‘The Luoping site dates from the Middle Triassic and contains one of the most diverse marine fossil records in the world,’ said Professor Benton. ‘It has yielded 20,000 fossils of fishes, reptiles, shellfish, shrimps and other seabed creatures. We can tell that we’re looking at a fully recovered ecosystem because of the diversity of predators, most notably fish and reptiles. It’s a much greater diversity than what we see in the Early Triassic – and it’s close to pre-extinction levels.’
Reinforcing this conclusion is the complexity of the food web, with the bottom of the food chains dominated by species typical of later Triassic marine faunas – such as crustaceans, fishes and bivalves – and different from preceding ones.
Just as important is the ‘debut’ of top predators – such as the long-snouted bony fish Saurichthys, the ichthyosaur Mixosaurus, the sauropterygian Nothosaurus and the prolacertiform Dinocephalosaurus – that fed on fishes and small predatory reptiles. link.
Wednesday, December 22, 2010
Internal anatomy of the coelacanth, Latimeria chalumnae.
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.
Sunday, December 19, 2010
Read the comic book bio of RCA at Atomic Surgery.
Download Central Asiatic Expeditions of the American Museum of Natural History, under the leadership of Roy Chapman Andrews : preliminary contributions in geology, palaeontology, and zoology (1926).
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.
Saturday, December 18, 2010
The holotype specimen CEUM 7319, a maxilla.
Geminiraptor suarezarum, found on BLM lands near Green River, UT, is the oldest reported "raptor-like" troodontid dinosaur in North America (125 million years old).Troodontid dinosaurs like Geminiraptor are "raptor-like" dinosaurs that are often credited with being more intellectually advanced. In fact, in 1982 an imaginative intelligent troodontid "dinosauroid" was proposed by Dale Russell of the National Museum Canada, as the logical consequence if dinosaurs had not gone extinct. This fantastic reconstruction has been criticized as being too anthropomorphic, but was based on the fact that the troodontid braincase was as much as six times larger than other dinosaurs.
Geminiraptor, at about 125 million years of age, is easily the oldest. The incomplete upper jaw inflated by a large and unique air sack readily identifies the fossil as belonging to a new species of troodontid.
Comparison of the maxilla of Geminiraptor suarezarum to those of other paravians.
Geminiraptor, meaning "Twin Predatory Thief of the Suarezes" is named in honor of Marina and Selina Suarez, graduate students from Temple University in Philadelphia, PA.
Owen (July 20, 1804 – Dec. 18, 1892) 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).
Lamarck (Aug.1, 1744 – Dec. 18, 1829) waa a 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.
Dobzhansky (Jan. 25, 1900 – Dec. 18, 1975) 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.
Tuesday, December 14, 2010
In 1846 Agassiz came to the U.S. to lecture before Boston's Lowell Institute. Offered a professorship of Zoology and Geology at Harvard in 1848, he decided to stay, becoming a citizen in 1861. His innovative teaching methods altered the character of natural science education in the U.S. Link
More info HERE
Sunday, December 12, 2010
Douglas is probably best known for playing the Phantom Zone Villianess Ursa in the 1978 Superman movie.
Saturday, December 11, 2010
On this day in 1955 the Czech film, Cesta do praveku, by Karl Zeman debuted in East Germany.
It was laters redubbed and shown with additional footage as Journey to the Beginning of Time in the USA.
Tuesday, December 07, 2010
Louis Antoine Marie Joseph Dollo (Dec. 7, 1857 – April 19, 1931) was a French vertebrate paleontologist who stated Dollo's Law of Irreversibility whereby in evolution an organism never returns exactly to its former state such that complex structures, once lost, are not regained in their original form. (While generally true, some exceptions are known.)
He began as an assistant (1882), became keeper of mammals (1891) at the Royal Museum of Natural History in Brussels where he stayed most of his life. He was a specialist in fossil fishes, reptiles, birds, and their palaeoecology. He supervised the excavation of the famous, multiple Iguanodons found in 1878 by miners deep underground, at Bernissart, Belgium. image
Art © Julius Csotonyi
A phylogenetic analysis indicates that Koreaceratops is positioned between Archaeoceratops and all more derived neoceratopsians, and the elongation of caudal neural spines was an important derived character in non-ceratopsid neoceratopsians. The very tall caudal neural spines in Koreaceratops, Montanoceratops, Udanoceratops, Protoceratops, and Bagaceratops appear to be homoplasious, suggesting an independent adaptation, possibly for swimming. Skeletal evidence suggests that obligate quadrupedalism occurred gradually in neoceratopsians progressing from bipedal through facultative quadrupedalism, to complete quadrupedalism in Coronosauria.
Saturday, December 04, 2010
Thomas Hunt Morgan (Sept. 25, 1866 – Dec. 4, 1945) was an American zoologist and geneticist, famous for his experimental research with the fruit fly by which he established the chromosome theory of heredity. He discovered that a number of genetic variations were inherited together and that this was because their controlling genes occurred on the same chromosome. In 1908, Morgan began breeding experiments with the fruit fly Drosophila melanogaster.
His study of the characteristics inherited by mutants ultimately enabled him to determine the precise behaviour and exact localization of genes. Morgan and his colleagues produced the first chromosome maps in 1911. Though this work was not widely accepted initially, Morgan was awarded a Nobel Prize for physiology or medicine in 1933. image
Friday, December 03, 2010
Disney Explains evolution. A Classic!
In general, the amount of influence temperature has on reaction speeds varies drastically, the group found. In one slow reaction, for instance, raising the temperature from 25 to 100 degrees Celsius increases the reaction rate 10 million fold.
High temperatures were probably a crucial influence on reaction rates when life began forming in hot springs and submarine vents. Later, the cooling of the earth provided selective pressure for primitive enzymes to evolve and become more sophisticated. link.
Thursday, December 02, 2010
Frank Reicher (Dec. 2, 1875 – Jan. 19, 1965) was born in Munich,Germany and had a long career in Hollywood. He appeared in over 200 films, often playing small roles in minor films, and he directed over three dozen silent movies.
He is best know for playing Capt. Englehorn in King King (1933), and it’s quickie sequel Son of Kong from later that same year.
Wednesday, December 01, 2010
Global warming devastated tropical rainforests 300 million years ago. Now scientists report the unexpected discovery that this event triggered an evolutionary burst among reptiles -- and inadvertently paved the way for the rise of dinosaurs, 100 million years later.This event happened during the Carboniferous Period. At that time, Europe and North America lay on the equator and were covered by steamy tropical rainforests. But when the Earth's climate became hotter and drier, rainforests collapsed and fragmented into small 'islands' of forest. This isolated populations of reptiles and each community evolved in a separate direction, leading to an increase in diversity."
Mike Benton of the University of Bristol added: "This is a classic ecological response to habitat fragmentation. You see the same process happening today whenever a group of animals becomes isolated from its parent population. It's been studied on traffic islands between major road systems or, as Charles Darwin famously observed in the Galapagos, on oceanic islands."
To reach their conclusions, the scientists studied the fossil record of reptiles before and after rainforest collapse. They showed that reptiles became more diverse and even changed their diet as they struggled to adapt to rapidly changing climate and environment. link
The Hardy-Weinberg equation
Haldane's book, The Causes of Evolution (1932), summarized these results, especially in its extensive appendix. This body of work was a component of what came to be known as the "modern evolutionary synthesis", re-establishing natural selection as the premier mechanism of evolution by explaining it in terms of the mathematical consequences of Mendelian genetics. From Wikipedia. More info here.
Monday, November 29, 2010
Tales to Astonish © Marvel Comics
"Basically, the dinosaurs disappear and all of a sudden there is nobody else eating the vegetation. That's an open food source and mammals start going for it, and it's more efficient to be an herbivore when you're big," says paper co-author Dr. Jessica Theodor.
Theodor says as well as confirming the dramatic growth in mammalian size after the dinosaurs, the study shows that the ecosystem is able to reset itself relatively quickly.
"You lose dinosaurs 65 million years ago, and within 25 million years the system is reset to a new maximum for the animals that are there in terms of body size. That's actually a pretty short time frame, geologically speaking," she says. "That's really rapid evolution."
"Nobody has ever demonstrated that this pattern is really there. People have talked about it but nobody has ever gone back and done the math," says Theodor one of the 20 researchers from around the world who worked on the study. link
The largest land mammals that ever lived, Indricotherium and Deinotherium, would have towered over the living African elephant. The tallest on diagram, Indricotherium, an extinct rhino relative, lived during the Eocene to the Oligocene Epoch (37 to 23 million years ago) and reached a mass of 15,000 kg, while Deinotherium (an extinct proboscidean, related to modern elephants) was around from the late-Miocene until the early Pleistocene (8.5 to 2.7 million years ago) and weighed as much as 17,000 kg.
Sunday, November 28, 2010
He showed that mammalian eggs were not the follicles of the ovary but microscopic particles inside the follicles. He described the development of the embryo from layers of tissue, which he called germ layers, and demonstrated similarities in the embryos of different species of vertebrates.
From Today In Science History
Wednesday, November 24, 2010
From Today In Science History:
In 1859, The Origin of Species by Means of Natural Selection was published in England to great acclaim. In this groundbreaking book by British naturalist Charles Darwin, he argued that species are the result of a gradual biological evolution in which nature encourages, through natural selection, the propagation of those species best suited to their environments. This book is unquestionably one of the most influential in the history of science.
Tuesday, November 23, 2010
The Early Cretaceous of Utah has two new species of iguanodonts that are beaked herbivorous dinosaurs.Iguanodonts are found all over the world in rocks dating to the Early Cretaceous Epoch (~145.5-99.6 million years ago). Their fossils are particularly abundant and diverse in Europe and east-central Asia with Europes Iguanodon being only the second formally named dinosaur in 1825.
Hippodraco scutodens (“horse-dragon, shield tooth”) (above) was found at a site north of Arches National Park. It lived approximately 124 million years ago, at the same time as the predator Utahraptor.
Iguanacolossus fortis (“mighty colossal Iguana”) (above) was found at a site near the town of Green River. It is ~30ft long and is probably a few million years older than Hippodraco.
Reduced consensus tree of 11,850 MPTs of 358 steps each, following ordering of 22 multistate characters. Numbers below and to the left of some nodes correspond to the following clade names: 1, Ornithopoda; 2, Iguanodontia; 3, Rhabdodontidae; 4, Dryomorpha; 5, Dryosauridae; 6, Ankylopollexia; 7, Styracosterna; 8, Hadrosauriformes; 9, Hadrosauroidea.
Saturday, November 20, 2010
Scientists say the unique shape of the vertebrae of the 33-million-year-old African lizard fossil links it with its cousin the Komodo, which has only been around for some 700,000 years.
"The African fossil was found on the surface of a windswept desert," said Holmes. "It's definitely from the lizard genus Varanus and there are more than 50 species alive today, including Komodos and other large lizards."
Holmes says the telltale African vertebrae fossils belonged to a lizard that was about a metre- and-a-half long whose ability to swim may be key to figuring out how more than 30 million years later its ancestors turned up on the other side of the world.
Holmes says the ancient African Varanus specimen was found on land that was once the bottom of a river or small lake. "Whether the animals lived in the water or surrounding land, we don't know, but we do know that some modern day species of Varanus are comfortable swimming in fresh water."
The work runs counter to some prevailing theories about the origins of some ancient fossil types found in Africa including Varanus lizards and some fresh-water fish. "The assumption for several types of ancient African fossils is that the animals didn't originate in Africa but came there from Asia," says Holmes. "But the fossil record of Varanus shows exactly the opposite path of migration." link
In 1851, Dawson and Lyell teamed up again to examine the interiors of fossil tree trunks at Joggins, Nova Scotia. They discovered the remains of some of the earliest known reptiles, Hylonomus lyelli, along with other rare fossils, propelling this part of the world into the international spotlight.
Dawson became principal of McGill College in Montreal in 1854, which he made into a reputable institution. He remained there, teaching geology and palaeontology and acting as librarian, until his retirement. One of his lifelong dreams was realized in 1882 when Peter Redpath gave money to McGill for the construction and establishment of a museum, naming Dawson as director. Today the Peter Redpath Museum of Natural History houses many specimens from Dawson's personal collection.
Info from HERE and HERE. Images from HERE and HERE.
Thursday, November 18, 2010
He was a student of all aspects of movie making from directing to distribution, and instrumental in the 1916 formation of the Lincoln Motion Picture Company, created to produce what were called “race movies.” Johnson left the company after it had released three films, rumored to have been “encouraged” by Universal to do so or lose any opportunity for parts at the bigger studio.
Johnson - a childhood friend of Lon Chaney - portrayed a variety of ethnicities in his long career; one of the few black actors of Hollywood’s early era to be allowed any diversity in roles.” From Kong Is King.net
Controversial claims that enormous prehistoric winged beasts could not fly have been refuted by the most comprehensive study to date which asserts that giant pterosaurs were skilled in flight.New research indicates that the giant pterosaurs took off by using all four of their limbs and effectively ‘pole-vaulting’ over their wings using their leg muscles and pushing from the ground using their powerful arm muscles. Once airborne they could fly huge distances and even cross continents.
These creatures were not birds; they were flying reptiles with a distinctly different skeletal structure, wing proportions and muscle mass. They would have achieved flight in a completely different way to birds and would have had a lower angle of take off and initial flight trajectory. The anatomy of these creatures is unique.”
Drs Witton and Habib suggest that, with up to 50 kg of forelimb muscle, the creatures could easily have launched themselves into the air despite their massive size and weight.
They concluded that not only could pterosaurs fly, they could do so extremely well and could have traveled huge distances and even crossed continents. It’s unlikely that they would need to flap continuously to remain aloft but would flap powerfully in short bursts with their large size allowing them to achieve rapid cruising speeds. link
Vist Pterosaur-Net Blog, a blog in the spirit of the palaeoblog, but all about pterosaurs. Thanks for the Kong image guys!Too bad the "junk in the trunk" entry slips off the front page. Victoria, shouldn't that be immortalized in a new Currie Lab t-shirt?
Wednesday, November 17, 2010
Willis O'Brien and produced by Herbert M. Dawley. When O’Brien went on to greater fame with The Lost World Dawley sued the film makers for patent infrigment, claiming that he, not O’Brien, had invented stop-motion animation. Although this was not the case, filming saw head up while the case was sorted out.
Both O’Brien and Hawley star as the ghost of Mad Dick and Uncle Jack Holmes, respectively.
T. rex's rear end has been given a makeover by University of Alberta graduate student Scott Persons. His extensive research shows that powerful tail muscles made the giant carnivore one of the fastest moving hunters of its time.As Persons says, "contrary to earlier theories, T. rex had more than just junk in its trunk."
The tails of both T.rex and modern animals are given their shape and strength by rib bones attached to the vertebrae. Persons found that the ribs in the tail of T. rex are located much higher on the tail. That leaves much more room along the lower end of the tail for the caudofemoralis muscles to bulk-up and expand. Without rib bones to limit the size of the caudofemoralis muscles, they became a robust power-plant enabling T.rex to run.
Persons extensive measurements of T.rex bones and computer modeling shows previous estimates of the muscle mass in the dinosaur's tall were underestimated by as much as 45 per cent.
That led many earlier T. rex researchers to believe the animal lacked the necessary muscle mass for running which in turn limited its hunting skills. That lack of speed cast T. rex in the role of a scavenger only able to survive by feeding on animals killed by other predators.
As for an T. rex's exact speed, researchers say that is hard to measure, but Persons says it could likely run down any other animal in its ecosystem. link
Read his story over at Atomic Surgery
The Hall of African Mammals at the American Museum of Natural History exists thanks to the efforts of Carl Akeley (May 19, 1864 - Nov 17, 1926) who was the kind of adventurer that Indy Jones could only dream of being.
He died on an African expedition in 1926, ten years before this hall was completed and was buried in a place depicted in the Hall's famous Gorilla Diorama. Of course we approach collecting and conservation differently today, but Akeley is to be commended for his love of nature and his desire to present its hidden corners to the world.
From Today In Science History:
Carl Ethan Akeley was an American naturalist and explorer who developed the taxidermic method for mounting museum displays to show animals in their natural surroundings. His method of applying skin on a finely molded replica of the body of the animal gave results of unprecedented realism and elevated taxidermy from a craft to an art. He mounted the skeleton of the famous African elephant Jumbo. He invented the Akeley cement gun to use while mounting animals, and the Akeley camera which was used to capture the first movies of gorillas.