Art by Henry Boltinoff, Showcase #41< DC Comics, 1962
Plus some Science Facts from Showcase #40:
Monday, December 31, 2012
Thursday, December 27, 2012
Sunday, December 16, 2012
Died This Day: Eugene Dubois
Eugene Dubois (Jan. 28, 1858-Dec. 16, 1940) joined the Dutch Army as a medical officer, and used spare time from his medical duties to search for fossils, first in Sumatra and then in Java.
He searched on the banks of the Solo River, with two assigned engineers and a crew of convict labourers to help him. In September 1890, his workers found a human, or human-like, fossil at Koedoeng Broeboes. This consisted of the right side of the chin of a lower jaw and three attached teeth. In August 1891 he found a primate molar tooth.
Two months later and one
meter away was found an intact skullcap, the fossil which would be known as Java Man. In August 1892, a third primate fossil, an almost complete left thigh bone, was found between 10 and 15 meters away from the skullcap.
In 1894 Dubois published a description of his fossils, naming them Pithecanthropus erectus (now Home erectus), describing it as neither ape nor human, but something intermediate. In 1895 he returned to Europe to promote the fossil and his interpretation. A few scientists enthusiastically endorsed Dubois' work, but most disagreed with his interpretation. Many scientists pointed out similarities between the Java Man skullcap and Neandertal fossils.
Around 1900 Dubois ceased to discuss Java Man, and hid the fossils in his home while he moved on to other research topics. geology and paleontology. It was not until 1923 that Dubois, under pressure from scientists, once again allowed access to the Java Man fossils. That and the discovery of similar fossils caused it to once again become a topic of debate.
He searched on the banks of the Solo River, with two assigned engineers and a crew of convict labourers to help him. In September 1890, his workers found a human, or human-like, fossil at Koedoeng Broeboes. This consisted of the right side of the chin of a lower jaw and three attached teeth. In August 1891 he found a primate molar tooth.Two months later and one
meter away was found an intact skullcap, the fossil which would be known as Java Man. In August 1892, a third primate fossil, an almost complete left thigh bone, was found between 10 and 15 meters away from the skullcap.In 1894 Dubois published a description of his fossils, naming them Pithecanthropus erectus (now Home erectus), describing it as neither ape nor human, but something intermediate. In 1895 he returned to Europe to promote the fossil and his interpretation. A few scientists enthusiastically endorsed Dubois' work, but most disagreed with his interpretation. Many scientists pointed out similarities between the Java Man skullcap and Neandertal fossils.
Around 1900 Dubois ceased to discuss Java Man, and hid the fossils in his home while he moved on to other research topics. geology and paleontology. It was not until 1923 that Dubois, under pressure from scientists, once again allowed access to the Java Man fossils. That and the discovery of similar fossils caused it to once again become a topic of debate.
Thursday, December 13, 2012
Paleozoic Soft Tissue Preservation in Ostracods
A Silurian myodocope with preserved soft-parts: cautioning the interpretation of the shell-based ostracod record. Siviter, D.J., et al. Proc. R Soc. B 280 (1752), Feb., 2013.
Ventral view of the fossil Pauline avibella. Credit: D.J. Siveter, D. E. G. Briggs, D. J. Siveter, M. D. Sutton & S. C. Joomun.
Abstract: Ostracod crustaceans are the most abundant fossil arthropods. The Silurian Pauline avibella gen. et sp. nov., from the Herefordshire Lagerstätte, UK, is an extremely rare Palaeozoic example with soft-part preservation. Based on its soft-part morphology, especially the exceptionally preserved limbs and presence of lateral eyes, it is assigned to the myodocopid myodocopes. The ostracod is very large, with an epipod on the fifth limb pair, as well as gills implying the presence of a heart and an integrated respiratory–circulatory system as in living cylindroleberidid myodocopids. Features of its shell morphology, however, recall halocyprid myodocopes and palaeocopes, encouraging caution in classifying ostracods based on the carapace alone and querying the interpretation of their shell-based fossil record, especially for the Palaeozoic, where some 500 genera are presently assigned to the Palaeocopida.
Ventral view of the fossil Pauline avibella. Credit: D.J. Siveter, D. E. G. Briggs, D. J. Siveter, M. D. Sutton & S. C. Joomun.
Abstract: Ostracod crustaceans are the most abundant fossil arthropods. The Silurian Pauline avibella gen. et sp. nov., from the Herefordshire Lagerstätte, UK, is an extremely rare Palaeozoic example with soft-part preservation. Based on its soft-part morphology, especially the exceptionally preserved limbs and presence of lateral eyes, it is assigned to the myodocopid myodocopes. The ostracod is very large, with an epipod on the fifth limb pair, as well as gills implying the presence of a heart and an integrated respiratory–circulatory system as in living cylindroleberidid myodocopids. Features of its shell morphology, however, recall halocyprid myodocopes and palaeocopes, encouraging caution in classifying ostracods based on the carapace alone and querying the interpretation of their shell-based fossil record, especially for the Palaeozoic, where some 500 genera are presently assigned to the Palaeocopida.
Wednesday, December 12, 2012
Gigantism in Sauropods
High C/N ratio (not low-energy content) of vegetation may have driven gigantism in sauropod dinosaurs and perhaps omnivory and/or endothermy in their juveniles. Wilkinson, D.M., and G. D. Ruxton. Functional Ecology, published online Dec 11, 2012.
Summary:
1. Sauropod dinosaurs were the largest terrestrial animals ever, and the combination of selective pressures that might have lead to such extraordinary sizes has long been discussed.
2. Here, we argue that a previous suggestion that large size may be a response to unusually high C/N ratios in available plant foods has been prematurely discarded. C/N ratios were likely to be high during much of the Mesozoic, and C/N ratio is entirely different from gross energy density as a measure of the value of a plant as food. In addition, we use recently published allometric equations for herbivore nitrogen and carbon use to make tentative calculations which suggest that if Mesozoic C/N ratios were greater than extant ones, this would have selected for one of two strategies: gigantism in ectothermic herbivores or endothermy (and selective foraging on high N material) in very small herbivores.
3. We speculate that smaller-bodied juvenile sauropods might have had a broader omnivorous diet and/or had higher mass-specific metabolic rates than adults. The former is potentially testable by changes in dentition; the latter matches evidence of high growth rates of juvenile sauropods. press release
Summary:
1. Sauropod dinosaurs were the largest terrestrial animals ever, and the combination of selective pressures that might have lead to such extraordinary sizes has long been discussed.
2. Here, we argue that a previous suggestion that large size may be a response to unusually high C/N ratios in available plant foods has been prematurely discarded. C/N ratios were likely to be high during much of the Mesozoic, and C/N ratio is entirely different from gross energy density as a measure of the value of a plant as food. In addition, we use recently published allometric equations for herbivore nitrogen and carbon use to make tentative calculations which suggest that if Mesozoic C/N ratios were greater than extant ones, this would have selected for one of two strategies: gigantism in ectothermic herbivores or endothermy (and selective foraging on high N material) in very small herbivores.
3. We speculate that smaller-bodied juvenile sauropods might have had a broader omnivorous diet and/or had higher mass-specific metabolic rates than adults. The former is potentially testable by changes in dentition; the latter matches evidence of high growth rates of juvenile sauropods. press release
Born This Day: Erasmus Darwin
Erasmus (Dec. 12, 1731 – April 18, 1802) was a prominent English physician, poet, philosopher, botanist, naturalist and the grandfather of naturalist Charles Darwin and the biologist Francis Galton. Erasmus Darwin was one of the leading intellectuals of 18th century England.
As a naturalist, he formulated one of the first formal theories on evolution in Zoonomia, or, The Laws of Organic Life (1794-1796). Although he did not come up with natural selection, he did discuss ideas that his grandson elaborated on sixty years later, such as how life evolved from a single common ancestor, forming "one living filament".
Download Zoonomia HERE
As a naturalist, he formulated one of the first formal theories on evolution in Zoonomia, or, The Laws of Organic Life (1794-1796). Although he did not come up with natural selection, he did discuss ideas that his grandson elaborated on sixty years later, such as how life evolved from a single common ancestor, forming "one living filament".
Download Zoonomia HERE
Sunday, December 09, 2012
Friday, December 07, 2012
Born This Day: Louis Dollo
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 From Today In Science History
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 From Today In Science History
Thursday, December 06, 2012
Nyasasaurus parringtoni, The Oldest Dinosaur?
The oldest dinosaur? A Middle Triassic dinosauriform from Tanzania. 2012. Nesbitt, S., et al. Biol. Lett.. 2013 9 1 20120949
Abstract: The rise of dinosaurs was a major event in vertebrate history, but the timing of the origin and early diversification of the group remain poorly constrained. Here, we describe Nyasasaurus parringtoni gen. et sp. nov., which is identified as either the earliest known member of, or the sister–taxon to, Dinosauria. Nyasasaurus possesses a unique combination of dinosaur character states and an elevated growth rate similar to that of definitive early dinosaurs. It demonstrates that the initial dinosaur radiation occurred over a longer timescale than previously thought (possibly 15 Myr earlier), and that dinosaurs and their immediate relatives are better understood as part of a larger Middle Triassic archosauriform radiation. The African provenance of Nyasasaurus supports a southern Pangaean origin for Dinosauria. Press release
Wednesday, December 05, 2012
Monday, December 03, 2012
RIP, Jack Lerbekmo
Jack Lerbekmo,
Professor Emeritus in the Department of Earth Sciences, University of Alberta, passed away on Thursday, November 29.
To paraphrase David Eberth, our understanding of the Cretaceous - Paleocene chronostrat record in the Western Canadian Sedimentary Basin owes much to him. All of us who work in that area owe him a huge debt.
His U of Alberta web page is here.
Professor Emeritus in the Department of Earth Sciences, University of Alberta, passed away on Thursday, November 29. To paraphrase David Eberth, our understanding of the Cretaceous - Paleocene chronostrat record in the Western Canadian Sedimentary Basin owes much to him. All of us who work in that area owe him a huge debt.
His U of Alberta web page is here.
Sunday, December 02, 2012
Born This Day: Frank Reicher
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.
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.
Saturday, December 01, 2012
Died This Day: Godfrey Harold Hardy
Hardy (Feb. 7, 1877 – Dec. 1, 1947) was an English mathematician known for his work in number theory and mathematical analysis. Although Hardy considered himself a pure mathematician, he nevertheless worked in applied mathematics when he formulated a law that describes how proportions of dominant and recessive genetic traits will propagate in a large population (1908). Hardy considered it unimportant but it has proved of major importance in blood group distribution. As it was also independently discovered by Weinberg, it is known as the Hardy-Weinberg principle.
The Hardy-Weinberg equation
The Hardy-Weinberg equation
Died This Day: J. B. S. Haldane
Haldane (Nov. 5, 1892 - Dec. 1, 1964) is best remembered along with E. B. Ford and R. A. Fisher one of the three major figures to develop the mathematical theory of population genetics. His greatest contribution was in a series of ten papers on "A Mathematical Theory of Natural and Artificial Selection" which was the major series of papers on the 
mathematical theory of natural selection. It treated many major cases for the first time, showing the direction and rates of changes of gene frequencies. It also pioneered in investigating the interaction of natural selection with mutation and with migration.
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.
mathematical theory of natural selection. It treated many major cases for the first time, showing the direction and rates of changes of gene frequencies. It also pioneered in investigating the interaction of natural selection with mutation and with migration.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.
Friday, November 30, 2012
Born This Day: Robert Broom
Robert Broom (Nov. 30, 1866 – April 6, 1951) was a South African doctor and paleontologist. From 1903 to 1910 he was professor of zoology and geology at Victoria College, Stellenbosch, South Africa, and subsequently he became keeper of vertebrate paleontology at the South African Museum, Cape Town.
Broom was first known for his study of mammal-like reptiles. After Raymond Dart's discovery of the Taung Child, an infant australopithecine, Broom's interest in paleoanthropology was heightened. In 1934 he jojned the staff of the Transvaal Museum in Pretoria as an Assistant in Palaeontology.
In the following years, he made a series of spectacular finds, including fragments from six hominids in Sterkfontein, which he named Plesianthropus transvaalensis. In 1937, Broom made his most famous discovery of Paranthropus robustus. These discoveries helped support Dart's claims for the Taung species.
The remainder of Broom's career was devoted to the exploration of these sites and the interpretation of the many early hominid remains discovered there. In 1946 he proposed the Australopithecinae subfamily. From Princeton.edu
Broom was first known for his study of mammal-like reptiles. After Raymond Dart's discovery of the Taung Child, an infant australopithecine, Broom's interest in paleoanthropology was heightened. In 1934 he jojned the staff of the Transvaal Museum in Pretoria as an Assistant in Palaeontology.
In the following years, he made a series of spectacular finds, including fragments from six hominids in Sterkfontein, which he named Plesianthropus transvaalensis. In 1937, Broom made his most famous discovery of Paranthropus robustus. These discoveries helped support Dart's claims for the Taung species.
The remainder of Broom's career was devoted to the exploration of these sites and the interpretation of the many early hominid remains discovered there. In 1946 he proposed the Australopithecinae subfamily. From Princeton.edu
Sunday, November 25, 2012
Died This Day: Nicolaus Steno
Steno (a.k.a. Niels Steensen, or Stensen)(Jan. 10 – Nov. 26, 1686) was a Danish geologist and anatomist who first made unprecedented discoveries in anatomy, then established 
some of the most important principles of modern geology. He was Danish royal anatomist for 2 years.
Interested by the characteristics and origins of minerals, rocks, and fossils, he published in Prodromus (1669) the law of superposition (if a series of sedimentary rocks has not been overturned, upper layers are younger and lower layers are older) and the law of original horizontality (although strata may be found dipping steeply, they were initially deposited nearly horizontal.) link image
some of the most important principles of modern geology. He was Danish royal anatomist for 2 years.Interested by the characteristics and origins of minerals, rocks, and fossils, he published in Prodromus (1669) the law of superposition (if a series of sedimentary rocks has not been overturned, upper layers are younger and lower layers are older) and the law of original horizontality (although strata may be found dipping steeply, they were initially deposited nearly horizontal.) link image
Saturday, November 24, 2012
Born This Day: Edwin Conklin
In addition to his work in embryology, he published a number of works on evolution. He estimated he made a thousand public lectures interpreting evolution to religious and lay groups. He was a leading critic of society's response to advanced technology. From Today in Science History
Published This Day: The Origin of The Species
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.
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.
Died This Day: Richard Carlson
Thursday, November 22, 2012
Born This Day: Skull Island Witch Doctor
Steve Clemente (born Esteban Clemento Morro Nov. 22, 1885—May 7, 1950) was a Mexican actor known for his many villainous roles. He began acting in his teens, signing up for his first movie, The Secret Man, in 1917. His later, numerous roles were usually bit parts and he was an expert knife thrower.
He was a known scene stealer and was famous for his villainous snarl. He later starred in such movies as The Most Dangerous Game (1932), playing Tartar, the second henchman of Count Zarrof and played the Witch King in King Kong (1933). From Wiki
He was a known scene stealer and was famous for his villainous snarl. He later starred in such movies as The Most Dangerous Game (1932), playing Tartar, the second henchman of Count Zarrof and played the Witch King in King Kong (1933). From Wiki
Tuesday, November 20, 2012
Born This Day: Robert Armstrong
Thursday, November 15, 2012
Farish Jenkins, RIP
Tuesday, November 13, 2012
Fantasia Premieres (1940)
The film featured Leopold Stokowski and the Philadelphia Orchestra performing a number of pieces of classical music to the film’s animated visuals. Igor Stravinsky’s “Rite of Spring” provided the score for the evolution of the Earth including a wonderful sequence on the extinction of the dinosaurs at the end of the Cretaceous. Many school teachers actually showed this sequence in science class up through the 1970's as it was one of the most accurate animated depictions to that date.
Born This Day: Helen Mack
Nov 13, 1913 – August 13, 1986
Monday, November 12, 2012
Born This Day: Julie Ege
Nov. 12, 1943 – April 29, 2008
Saturday, November 10, 2012
Xenoceratops - A New Centrosaur From Alberta
Art © Mark Schultz, 2012
Watch David Evans explain it all on Canada Am.
Died This Day: Gideon Mantell
Mantell (Feb. 3, 1790 – Nov. 10, 1852), a physician of Lewes in Sussex in southern England, had for years been collecting fossils in the sandstone of Tilgate forest, 
and he had discovered bones belonging to three extinct species: a giant crocodile, a plesiosaur, and Buckland's Megalosaurus. But in 1822 he found several teeth that "possessed characters so remarkable" that they had to have come from a fourth and distinct species of Saurian. After consulting numerous experts, Mantell finally recognized that the teeth bore an uncanny resemblance to the teeth of the living iguana, except that they were twenty times larger. 
In this paper, the second published description of a dinosaur, he concluded that he had found the teeth of a giant lizard, which he named Iguanodon, or "Iguana-tooth."
Mantell illustrated his announcement with a single lithographed plate. Mantell included at the bottom of the plate a drawing of a recent iguana jaw, which is shown four times natural size, and for further comparison, he added views of the inner and outer surface of a single iguana tooth, "greatly magnified."
The traditional story that Mantell's wife found the first teeth in 1822, while the doctor was visiting a patient, appears, alas, to be unfounded.
Info and plate from HERE.
and he had discovered bones belonging to three extinct species: a giant crocodile, a plesiosaur, and Buckland's Megalosaurus. But in 1822 he found several teeth that "possessed characters so remarkable" that they had to have come from a fourth and distinct species of Saurian. After consulting numerous experts, Mantell finally recognized that the teeth bore an uncanny resemblance to the teeth of the living iguana, except that they were twenty times larger. 
In this paper, the second published description of a dinosaur, he concluded that he had found the teeth of a giant lizard, which he named Iguanodon, or "Iguana-tooth."
Mantell illustrated his announcement with a single lithographed plate. Mantell included at the bottom of the plate a drawing of a recent iguana jaw, which is shown four times natural size, and for further comparison, he added views of the inner and outer surface of a single iguana tooth, "greatly magnified."
The traditional story that Mantell's wife found the first teeth in 1822, while the doctor was visiting a patient, appears, alas, to be unfounded.
Info and plate from HERE.
Monday, October 15, 2012
Premiered This Day: Unknown Island
This 1948 film written by Robert T. Shannon and directed by Jack Bernhard features some of the worst ‘man dressed up as a T. rex’ effects ever. Not a bad little story though.
Sunday, October 14, 2012
Born This Day: Jack Arnold
Jack Arnold (Oct. 14, 1916 - March 17, 1992) directed a number of classic SF films including The Creature From the Black Lagoon, Revenge of the Creature, The Incredible Shrinking Man, and It Came From Outer Space, as well as few not-so-classics (but still much loved) such as Monster on Campus. Throughout the ‘60’s and into the early 80’s he had a successful career as a TV producer and director.
Monday, October 01, 2012
Died This Day: Louis Leakey
Louis and Mary Leakey
From Today In Science History:
Leakey (Aug 7, 1903 – October 1, 1972), an archaeologist and anthropologist, was born in Kabete, Kenya, of English missionaries parents. Leakey was largely responsible for convincing scientists that Africa, rather than Java or China, was the most significant area to search for evidence of human origins. Leakey led fossil-hunting expeditions to eastern Africa from the 1920's.
He married Mary D. Nicol in 1936 and the couple discovered many important fossils together. In 1964, on an expedition to the Olduvai Gorge in Tanzania, he found fossil remains of, he believed, the earliest member of the genus of human beings. He named the species Homo habilis.
Sunday, September 30, 2012
Born This Day: Charles Lapworth
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.
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.
Friday, September 28, 2012
ROM Dino Comic
Did you know that the Royal Ontario Museum did a comic book to go with their excellent new dinosaur show, "Ultimate Dinosaurs"? And that it was illustrated by Gabriel Morrissette with colours by Bernie Mireault? Me either! Bernie kindly sent me this image:
And speaking of Bernie, he has a great new book out, "To Get Her" that you can buy HERE (I did!).
You may know Bernie from his terrific comic, The Jam, and well as being the creator of Dr. Robot (why is this not a TV series!).
Bernie also recently posted a thoughtful article about his experience at the En Masse table during the most recent Montreal Comic Con.
Sunday, August 12, 2012
Saturday, August 11, 2012
Died This Day: Lorenz Oken
In Die Zeugung, he discussed “the infusoria”—elementary units of living organisms—into which all flesh can be broken down. Higher animals, he proposed, consisted of constituent animalcules. Entities, whether plants or animals, became organisms by the fusion of these primal animals. Those elements lose all individuality and create a higher unity. From Today In Science History
More here
Monday, July 30, 2012
Tuesday, May 29, 2012
Ichthyostega Walks The Walk
Three-dimensional limb joint mobility in the early tetrapod Ichthyostega. 2012. S. Pierce, et al. Nature, published online May, 23.
Abstract: The origin of tetrapods and the transition from swimming to walking was a pivotal step in the evolution and diversification of terrestrial vertebrates. During this time, modifications of the limbs—particularly the specialization of joints and the structures that guide their motions—fundamentally changed the ways in which early tetrapods could move. Nonetheless, little is known about the functional consequences of limb anatomy in early tetrapods and how that anatomy influenced locomotion capabilities at this very critical stage in vertebrate evolution.
Here we present a three-dimensional reconstruction of the iconic Devonian tetrapod Ichthyostega and a quantitative and comparative analysis of limb mobility in this early tetrapod. We show that Ichthyostega could not have employed typical tetrapod locomotory behaviours, such as lateral sequence walking. In particular, it lacked the necessary rotary motions in its limbs to push the body off the ground and move the limbs in an alternating sequence.
Given that long-axis rotation was present in the fins of tetrapodomorph fishes, it seems that either early tetrapods evolved through an initial stage of restricted shoulder and hip joint mobility or that Ichthyostega was unique in this respect. We conclude that early tetrapods with the skeletal morphology and limb mobility of Ichthyostega were unlikely to have made some of the recently described Middle Devonian trackways.
Here we present a three-dimensional reconstruction of the iconic Devonian tetrapod Ichthyostega and a quantitative and comparative analysis of limb mobility in this early tetrapod. We show that Ichthyostega could not have employed typical tetrapod locomotory behaviours, such as lateral sequence walking. In particular, it lacked the necessary rotary motions in its limbs to push the body off the ground and move the limbs in an alternating sequence.
Given that long-axis rotation was present in the fins of tetrapodomorph fishes, it seems that either early tetrapods evolved through an initial stage of restricted shoulder and hip joint mobility or that Ichthyostega was unique in this respect. We conclude that early tetrapods with the skeletal morphology and limb mobility of Ichthyostega were unlikely to have made some of the recently described Middle Devonian trackways.
Monday, May 28, 2012
Extinct
Bob Rich won the 2012 Rueben Award for Newspaper Illustration at the National Cartoonist Society's 66th Annual Reuben Awards ceremony this past weekend.
Born This Day: Louis Agassiz
(Jean) Louis (Rodolphe) Agassiz (May 28, 1807 - Dec. 14, 1873) was a Swiss-born U.S. naturalist, geologist, and teacher who made revolutionary contributions to the study of natural science with landmark work on glacier activity and extinct fishes. Agassiz began his work in Europe, having studied at the University of Munich and then as chair in natural history in Neuchatel in Switzerland. While there he published his landmark multi-volume description and classification of fossil fish.
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
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, May 27, 2012
Book Review: Across Atlantic Ice: The Origin of America’s Clovis Culture by Dennis J. Stanford and Bruce A. Bradley
The Palaeoblog occasionally gets sent books to review which we get around to doing eventually. This one, dealing with the origins of the first Americans, falls more under archaeology than palaeontology, so I've asked the Cleveland Museum of Natural History's John Otis Hower Chair of Archaeology, Dr. Brian Redmond, to review this for us. Thanks Brian!Who were the first Americans? When did they come to the New World and by what routes? These questions have maintained a featured place in archaeological inquiry since the era of Thomas Jefferson, the recognized father of American Archaeology. This much-awaited book by two leading Paleoindian scholars argues for an origin, not from northeastern Asia as conventionally proposed, but across the north Atlantic from Iberia during the late glacial maximum, some 20,000 years ago. Using detailed, but not overly technical, presentations of late Pleistocene stone tool assemblages from Siberia to Chesapeake Bay, the authors state their case for the origin of the classic Clovis tool kit in eastern North America from Upper Paleolithic, Solutrean, migrants from Europe. Bradley uses his substantial experience as a stone tool analyst and flint-knapper to point out the intriguing similarities between bifacially-flaked spear and knife points found on both sides of the Atlantic. But most previous scholars have judged such a connection untenable due to the three to twelve thousand years that separated Solutrean from Clovis hunters. To fill the gap, Stanford and Bradley cite a growing body of archaeological evidence for a “pre-Clovis” occupation of eastern North America as early as 25,000 years ago. This overview of the evidence is highly informative, well-illustrated, and brings to print the newest data for Clovis progenitors in the mid-Atlantic region. The authors even make a good case that Solutrean seal hunters from Europe could have migrated north and west along the north Atlantic ice front and ended up in North America. Much less convincing is their claim for real historical affinity between Solutrean, pre-Clovis, and Clovis. In the end, the still sketchy pre-Clovis data base severely weakens the argument. But the book remains a fascinating and informative read for all students of the earliest American history.
Eoabelisaurus mefi, New Theropod from Patagonia
A Middle Jurassic abelisaurid from Patagonia and the early diversification of theropod dinosaurs. 2012. D. Pol and O. Rauhut. Royal Society B: Biological Sciences. Published online before print May 23.
Abstract: Abelisaurids are a clade of large, bizarre predatory dinosaurs, most notable for their high, short skulls and extremely reduced forelimbs. They were common in Gondwana during the Cretaceous, but exceedingly rare in the Northern Hemisphere. The oldest definitive abelisaurids so far come from the late Early Cretaceous of South America and Africa, and the early evolutionary history of the clade is still poorly known.
Here, we report a new abelisaurid from the Middle Jurassic of Patagonia, Eoabelisaurus mefi gen. et sp. nov., which predates the so far oldest known secure member of this lineage by more than 40 Myr. The almost complete skeleton reveals the earliest evolutionary stages of the distinctive features of abelisaurids, such as the modification of the forelimb, which started with a reduction of the distal elements.
The find underlines the explosive radiation of theropod dinosaurs in the Middle Jurassic and indicates an unexpected diversity of ceratosaurs at that time. The apparent endemism of abelisauroids to southern Gondwana during Pangean times might be due to the presence of a large, central Gondwanan desert. This indicates that, apart from continent-scale geography, aspects such as regional geography and climate are important to reconstruct the biogeographical history of Mesozoic vertebrates.
Abstract: Abelisaurids are a clade of large, bizarre predatory dinosaurs, most notable for their high, short skulls and extremely reduced forelimbs. They were common in Gondwana during the Cretaceous, but exceedingly rare in the Northern Hemisphere. The oldest definitive abelisaurids so far come from the late Early Cretaceous of South America and Africa, and the early evolutionary history of the clade is still poorly known.
Here, we report a new abelisaurid from the Middle Jurassic of Patagonia, Eoabelisaurus mefi gen. et sp. nov., which predates the so far oldest known secure member of this lineage by more than 40 Myr. The almost complete skeleton reveals the earliest evolutionary stages of the distinctive features of abelisaurids, such as the modification of the forelimb, which started with a reduction of the distal elements.
The find underlines the explosive radiation of theropod dinosaurs in the Middle Jurassic and indicates an unexpected diversity of ceratosaurs at that time. The apparent endemism of abelisauroids to southern Gondwana during Pangean times might be due to the presence of a large, central Gondwanan desert. This indicates that, apart from continent-scale geography, aspects such as regional geography and climate are important to reconstruct the biogeographical history of Mesozoic vertebrates.