From Today In Science History:
Lapworth (Sept. 30, 1842 - March 13, 1920) was an English geologist who proposed what came to be called the Ordovician period (505 to 438 million years old) of geologic strata. Lapworth is famous for his work with marine fossils called graptolites.
By fastidiously collecting the tiny, colonial sea creatures, he figured out the original order of layered rocks that had been faulted and folded in England's Southern Uplands. This method of correlating rocks with graptolites became a model for similar research throughout the world.
In 1879, Lapworth proposed a new classification of Lower Paleozoic rocks with the Ordovician, between the redefined Cambrian and Silurian periods. The name comes from an ancient Welsh tribe, the Ordovices.
Jumat, 30 September 2011
Kamis, 29 September 2011
Anatotitan, No More!
Cranial Growth and Variation in Edmontosaurs (Dinosauria: Hadrosauridae): Implications for Latest Cretaceous Megaherbivore Diversity in North America. 2011. N.E. Campione & D. C. Evans. PLoS ONE 6(9): e25186.
Abstract: The well-sampled Late Cretaceous fossil record of North America remains the only high-resolution dataset for evaluating patterns of dinosaur diversity leading up to the terminal Cretaceous extinction event. Hadrosaurine hadrosaurids (Dinosauria: Ornithopoda) closely related to Edmontosaurus are among the most common megaherbivores in latest Campanian and Maastrichtian deposits of western North America. However, interpretations of edmontosaur species richness and biostratigraphy have been in constant flux for almost three decades, although the clade is generally thought to have undergone a radiation in the late Maastrichtian.
We address the issue of edmontosaur diversity for the first time using rigorous morphometric analyses of virtually all known complete edmontosaur skulls. Results suggest only two valid species, Edmontosaurus regalis from the late Campanian, and E. annectens from the late Maastrichtian, with previously named taxa,including the controversial Anatotitan copei, erected on hypothesized transitional morphologies associated with ontogenetic size increase and allometric growth.
A revision of North American hadrosaurid taxa suggests a decrease in both hadrosaurid diversity and disparity from the early to late Maastrichtian, a pattern likely also present in ceratopsid dinosaurs. A decline in the disparity of dominant megaherbivores in the latest Maastrichtian interval supports the hypothesis that dinosaur diversity decreased immediately preceding the end Cretaceous extinction event.
'Nuff Said!
Abstract: The well-sampled Late Cretaceous fossil record of North America remains the only high-resolution dataset for evaluating patterns of dinosaur diversity leading up to the terminal Cretaceous extinction event. Hadrosaurine hadrosaurids (Dinosauria: Ornithopoda) closely related to Edmontosaurus are among the most common megaherbivores in latest Campanian and Maastrichtian deposits of western North America. However, interpretations of edmontosaur species richness and biostratigraphy have been in constant flux for almost three decades, although the clade is generally thought to have undergone a radiation in the late Maastrichtian.
We address the issue of edmontosaur diversity for the first time using rigorous morphometric analyses of virtually all known complete edmontosaur skulls. Results suggest only two valid species, Edmontosaurus regalis from the late Campanian, and E. annectens from the late Maastrichtian, with previously named taxa,including the controversial Anatotitan copei, erected on hypothesized transitional morphologies associated with ontogenetic size increase and allometric growth.
A revision of North American hadrosaurid taxa suggests a decrease in both hadrosaurid diversity and disparity from the early to late Maastrichtian, a pattern likely also present in ceratopsid dinosaurs. A decline in the disparity of dominant megaherbivores in the latest Maastrichtian interval supports the hypothesis that dinosaur diversity decreased immediately preceding the end Cretaceous extinction event.
'Nuff Said!
Kamis, 15 September 2011
Premiered This Day (1914): Gertie The Dinosaur
Winsor McCay (Sept. 26, 1987 – July 26, 1934) was one of the great American artists of the last century. He is best known for his newspaper comic strip Little Nemo in Slumberland that ran from 1905 to 1914, and the animated cartoon creation Gertie the Dinosaur (1914).
For this cartoon McCay hand drew each frame of film. He took it on a tour of the vaudeville circuit and delighted audiences by being able to ‘interact’ with Gertie. Gertie is considered by many as the first true animated character to be featured in a film.
For this cartoon McCay hand drew each frame of film. He took it on a tour of the vaudeville circuit and delighted audiences by being able to ‘interact’ with Gertie. Gertie is considered by many as the first true animated character to be featured in a film.
Selasa, 13 September 2011
Glass Lantern Field Slides Now Posted at the NMNH
This lantern slide is from a collection showing field excavations in Arizona, at the Grand Canyon and other unnamed locations in the Painted Desert.
A collection of newly digitized glass lantern slides, showing early 20th century paleontological digs and the preparation of fossils for display, is now available to the public from the Smithsonian Institution Archives and the National Museum of Natural History. Link from Wired.
Thanks to Matt Vavrek!
Laccognathus embryi
The 375-million-year-old Laccognathus embryi was d found at the same site as Tiktaalik, on Ellesmere Island in the remote Nunavut Territory of Arctic Canada. Laccognathus is a lobe-finned fish whose closest living relative is the lungfish. The creature probably grew to about 5 or 6 feet long and had a wide head with small eyes and robust jaws lined with large piercing teeth.
"Clearly these Late Devonian ecosystems were vicious places, and Laccognathus filled the niche of a large, bottom-dwelling, sit-and-wait predator with a powerful bite."
The researchers named the new species in honor of Dr. Ashton Embry, a Canadian geologist whose work in the Arctic islands paved the way for the authors' paleontological explorations.
The kind of fish known as Laccognathus (translates as pitted jaw) was previously only known from Eastern Europe. The discovery of Laccognathus embryi, the new species, extends the geographic range of Laccognathus to North America and confirms direct connection of the North American and European landmasses during the Devonian Period.
Published in JVP.
Sabtu, 10 September 2011
Born This Day: Stephen Jay Gould
Here’s a nice piece on Gould by Henry Lowood from the Stanford Presidential Lectures in the Humanities and Arts.
Jumat, 09 September 2011
Premiered This Day: Mighty Mightor!
"While on a hunting trip, Tor and his faithful companion Tog rescue an ancient hermit from a Tyrannosarus rex. Grateful, the old man gives Tor a club which possesses great powers. Tor raises the club and he becomes Mightor, and Tog is transferred into a fire-breathing dragon. Together they become champions of good and the nemesis of evil!" From the opening narration. link.
Mighty Mightor debuted this day in 1967 as part of the Moby Dick and Mighty Mightor Hanna-Barbera cartoon show.
Mighty Mightor debuted this day in 1967 as part of the Moby Dick and Mighty Mightor Hanna-Barbera cartoon show.
Australopithecus sediba
Australopithecus sediba at 1.977 Ma and Implications for the Origins of the Genus Homo. R. Pickering, et al. Science 333: 1421-1423.
Five papers based on Australopithecus sediba have been published in Science on Sept. 9, 2011. They include an analysis of the most complete hand ever described in an early hominin, the most complete undistorted pelvis ever discovered, the highest resolution and most accurate scan of an early human ancestors brain ever made, new pieces of the foot and ankle skeleton, and one of the most accurate dates ever achieved for an early hominin site in Africa.
Five papers based on Australopithecus sediba have been published in Science on Sept. 9, 2011. They include an analysis of the most complete hand ever described in an early hominin, the most complete undistorted pelvis ever discovered, the highest resolution and most accurate scan of an early human ancestors brain ever made, new pieces of the foot and ankle skeleton, and one of the most accurate dates ever achieved for an early hominin site in Africa.
Au. sediba (MH-1) skull reconstruction (opaque) with endocast (green, opaque) partially visible as a result of virtual craniotomy. Dr K. Carlson, U. Witwatersrand.Abstract: Newly exposed cave sediments at the Malapa site include a flowstone layer capping the sedimentary unit containing the Australopithecus sediba fossils. Uranium-lead dating of the flowstone, combined with paleomagnetic and stratigraphic analysis of the flowstone and underlying sediments, provides a tightly constrained date of 1.977 ± 0.002 million years ago (Ma) for these fossils. This refined dating suggests that Au. sediba from Malapa predates the earliest uncontested evidence for Homo in Africa.
The cranium of the juvenile skeleton of Au.sediba. Pic courtesy of Lee Berger & U. Witwatersrand.
Born This Day: William Lonsdale
William Lonsdale (Sept. 9, 1794 – Nov. 11, 1891 ) was an English geologist and paleontologist whose study of coral fossils found in Devon, suggested (1837) certain of them were intermediate between those typical of the older Silurian System (408 to 438 Ma) and those of the later Carboniferous System (286 to 360 Ma. Geologists Roderick Murchison and Adam Sedgwick agreed and named this new geologic system after its locale - the Devonian Period (1839).
Lonsdale's early career was as an army officer (1812-15) and later he became curator and librarian of the Geological Society of London (1829-42). He recognised that fossils showed how species changed over time, and more primitive organisms are found in lower strata.
From Today In Science History
Lonsdale's early career was as an army officer (1812-15) and later he became curator and librarian of the Geological Society of London (1829-42). He recognised that fossils showed how species changed over time, and more primitive organisms are found in lower strata.
From Today In Science History
Born This Day: Joseph Leidy
From The Academy of Natural Sciences:
Leidy (Sept. 9, 1823 - April 30, 1891) is known as the "Father of American Vertebrate Paleontology". He described the first relatively complete dinosaur skeleton, Hadrosaurus, and introduced many American and European scientists to the fossil riches of the American West. Leidy's consummate skill in comparative anatomy would allow him to identify and characterize even the most fragmentary fossil material.
Leidy was also the "Founder of American Parasitology," a Professor of Anatomy at the University of Pennsylvania, a pioneering protozoologists, an influential teacher of Natural History, an accomplished microscopist and scientific illustrator, and an expert on a variety of subjects encompasing the earth and natural sciences. He published scientific papers on more than a thousand extinct and living protozoa, fungi and invertebrates and vertebrates as well as an assortment of publications on human biology and medicine. He was also one of the earliest supporters of Charles Darwin.
Leidy (Sept. 9, 1823 - April 30, 1891) is known as the "Father of American Vertebrate Paleontology". He described the first relatively complete dinosaur skeleton, Hadrosaurus, and introduced many American and European scientists to the fossil riches of the American West. Leidy's consummate skill in comparative anatomy would allow him to identify and characterize even the most fragmentary fossil material.
Leidy was also the "Founder of American Parasitology," a Professor of Anatomy at the University of Pennsylvania, a pioneering protozoologists, an influential teacher of Natural History, an accomplished microscopist and scientific illustrator, and an expert on a variety of subjects encompasing the earth and natural sciences. He published scientific papers on more than a thousand extinct and living protozoa, fungi and invertebrates and vertebrates as well as an assortment of publications on human biology and medicine. He was also one of the earliest supporters of Charles Darwin.
Kamis, 08 September 2011
Rabu, 07 September 2011
Born This Day: Ferdinand Vandiveer Hayden
From Today In Science History
Hayden (Sept. 7, 1829 - Dec. 22, 1887) 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.
Hayden (Sept. 7, 1829 - Dec. 22, 1887) 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.
Born This Day: Comte Georges-Louis Leclerc de Buffon
Buffon (Sept. 7, 1707 – April 16, 1788) was a French naturalist, who formulated a crude theory of evolution and was the first to suggest that the earth might be older than suggested by the Bible.
In 1739 he was appointed keeper of the Jardin du Roi, a post he occupied until his death. There he worked on a comprehensive work on natural history, for which he is remembered, Histoire naturelle, générale et particulière. He began this work in 1749, and it dominated the rest of his life. It would eventually run to 44 volumes, including quadrupeds, birds, reptiles and minerals.
He proposed (1778) that the Earth was hot at its creation and, from the rate of cooling, calculated its age to be 75,000 years, with life emerging some 40,000 years ago.
From Today In Science History. Stamp from HERE.
More info on Buffon from UC-Berkeley.
In 1739 he was appointed keeper of the Jardin du Roi, a post he occupied until his death. There he worked on a comprehensive work on natural history, for which he is remembered, Histoire naturelle, générale et particulière. He began this work in 1749, and it dominated the rest of his life. It would eventually run to 44 volumes, including quadrupeds, birds, reptiles and minerals.
He proposed (1778) that the Earth was hot at its creation and, from the rate of cooling, calculated its age to be 75,000 years, with life emerging some 40,000 years ago.
From Today In Science History. Stamp from HERE.
More info on Buffon from UC-Berkeley.
Senin, 05 September 2011
Sabtu, 03 September 2011
Kamis, 01 September 2011
Died This Day: Luis Alvarez
Alvarez (June 13, 1911 - Sept. 1, 1988) was an American experimental physicist who was awarded the Nobel Prize for Physics in 1968 for work that included the discovery of many resonance particles --subatomic particles having extremely short lifetimes and occurring only in high-energy nuclear collisions.
In about 1980 Alvarez (left) helped his son, the geologist Walter Alvarez (right), publicize Walter's discovery of a worldwide layer of clay that has a high iridium content and which occupies rock strata at the geochronological boundary between the Mesozoic and Cenozoic eras; i.e., about 66.4 million years ago.
They postulated that the iridium had been deposited following the impact on Earth of an asteroid or comet and that the catastrophic climatic effects of this massive impact caused the extinction of the dinosaurs. Though initially controversial, this widely publicized theory gradually gained support as the most plausible explanation of the abrupt demise of the dinosaurs.
Read more HERE. Image from HERE.
In about 1980 Alvarez (left) helped his son, the geologist Walter Alvarez (right), publicize Walter's discovery of a worldwide layer of clay that has a high iridium content and which occupies rock strata at the geochronological boundary between the Mesozoic and Cenozoic eras; i.e., about 66.4 million years ago.
They postulated that the iridium had been deposited following the impact on Earth of an asteroid or comet and that the catastrophic climatic effects of this massive impact caused the extinction of the dinosaurs. Though initially controversial, this widely publicized theory gradually gained support as the most plausible explanation of the abrupt demise of the dinosaurs.
Read more HERE. Image from HERE.
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