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.

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

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(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

Book Review: Across Atlantic Ice: The Origin of America’s Clovis Culture by Dennis J. Stanford and Bruce A. Bradley

Across Atlantic Ice: The Origin of America’s Clovis Culture. Dennis J. Stanford and Bruce A. Bradley. University of California Press, Berkeley, 2012, 319 pages.

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.

Doug Henderson Prints and Originals for Sale

After a seemingly long public absence, Doug Henderson is now on Facebook and selling signed prints and original art through Ebay (earthistory2ktz). You can probably also find him on either site by searching his name.

Opened This Day: American Museum of Natural History

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From Today In Scince History:

On this day in 1871, the American Museum of Natural History opened to the public in New York City. The Museum’s collection went on view for the first time in the Central Park Arsenal, the Museum’s original home, on the eastern side of Central Park.

The museum began from the efforts of Albert Smith Bickmore, one-time student of Harvard zoologist Louis Agassiz, who was successful in his proposal to create a natural history museum in New York City, with the support of Theodore Roosevelt and J. Pierpont Morgan. The Governor of New York signed a bill officially creating the American Museum of Natural History on April 6, 1869.

Philoventator curriei, A New Troodontid from China

The taxonomy of the troodontid IVPP V 10597 reconsidered. 2012. Xu Xing, et al. Vertebrata PalAsiatica 50: 140-150.

Abstract: The partial troodontid hindlimb IVPP V 10597 was originally described as a juvenile Saurornithoides mongoliensis. The present study reconsiders the taxonomic placement of this interesting specimen, given the significant advances in understanding of the Troodontidae that have taken place since it was first described. Morphological comparisons and numerical phylogenetic analyses indicate that V 10597 is more closely related to the sympatric linhevenator tani than to Saurornithoides mongoliensis raising the possibility that V 10597 might be a juvenile L. tani. However, V 10597 differs significantly from other troodontids, including L. tani in numerous hindlimb features and particularly in the proportions of various hindlimb elements. These differences are likely to be taxonomic, and suggest that V 10597 represents a new troodontid. Furthermore. histological analysis indicates that V 10597 is unlikely to be a juvenile of L. tani or any other large troodontid. Based on the available morphological and histological information. We propose the new taxon, Philovenator curriei gen. et sp. nov., based on V 10597.

The Return of Steve Bissette's Tyrant!

More info HERE

Born This Day: Willi Henning

From the Willi Hennig Society :

Hennig (April 20, 1913 – Nov. 5, 1976) is best known for developing phylogenetic systematics,  a coherent theory of the investigation and presentation of the  relations that exist among species. Contrary to the position generally  held during his time, Hennig viewed historical inference as a strictly  logical and scientific endeavor. He first summarized his ideas in 1950  in German which became more widely known with the publication of the  English revision, Phylogenetic Systematics (Hennig, 1966).


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Major Hennigian principles are:

1. Relationships among species are to be interpreted strictly genealogically, as sister-lineages, as clade relations. Empirically, a phylogenetic hypothesis may be determined.
2. Synapomorphies provide the only evidence for identifying relative recency of common ancestry. Synapomorphies are understood to be the shared-derived (evolved, modified) features of organisms.

3. Maximum conformity to evidence is sought  (his auxiliary principle). Choice among competing cladistic  propositions (cladograms) is decided on the basis of the greatest amount  of evidence, the largest number of synapomorphies explainable as  homologues.

4. Whenever possible, taxonomy must be logically consistent with the inferred pattern of historical relationships. The rule of monophyly is to be followed, thereby each clade can have its unique place in the hierarchy of taxonomic names.

More info about Henning HERE. photo.

Born This Day: Sir William Logan

From Today in Science History:

Logan (April 20, 1798 – June 22, 1875) was a Canadian geologist dubbed the "Father of Canadian Geology." He began is career making geologic maps of coalfields in Wales, noting the relationship between the underlying clay layers and fossil tree roots with local coal beds. This substantiated the theory that coal beds are formed in place.

When he began as director (1842-69) of the new Geological Survey of Canada, its geology was virtually unknown. He produced the monumental Report on the Geology of Canada (1863) which recorded 20 years of research, fieldwork, plotting maps, preparing reports, and examining fossil and mineral specimens.

Image and more info from Natural Resources Canada. For a more colourful summary of the man and his life go HERE.

Died This Day: Eramus 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".

Although some of his ideas on how evolution might occur are quite close to those of Lamarck, Erasmus Darwin also talked about how competition and sexual selection could cause changes in species. link

Download Zoonomia HERE

Premiered This Day: Women of The Prehistoric Planet

Written and directed by Arthur C. Pierce, and starring the perennial C-list actor John Agar (who had his own Prehistoric Theme Park!), this is just about as bad as it gets.

Premiered This Day: The Land That Time Forgot

Directed by Kevin O’Connor, this 1975 film starred Doug McClure.

Died This Day: Amanz Gressly

Gressly (July 17, 1814 - April 13, 1865) was a Swiss geologist and paleontologist who originated the study of stratigraphic facies when he discovered lateral differences in the character and fossil content of strata in the Jura Mountains, reflecting a variation of the original environment of deposition.

The "Gressly's lizard" dinosaur was named Gresslyosaurus (1857) to honour Amanz Gressly and to replace the preoccupied Dinosaurus Ruetimeyer 1856). It is now synonymized with Plateosaurus. From Today in Science History

Free, Online journal, eLife, to Compete with Nature and Science

From BBC News:

One of the world's largest research charities, the Wellcome Trust, is to establish a free, online publication called eLife to compete with established academic journals.

They say their new title could be a "game changer" forcing other publishing houses to increase free access.

More than 9,000 scientists are boycotting a leading paid-for publisher for restricting access to their papers.

The Wellcome Trust's move is the latest salvo in a battle about ownership of, and access to, the published work of scientists that has been simmering underneath the sedate surface of scientific research for years.

Born This Day: Kenneth Oakley

From Today in Science History:

Oakley (April 7, 1911 - November 2, 1981) was an English physical anthropologist, geologist, and paleontologist best known for his work in the relative dating of fossils by fluorine content. While working for the British Natural History Museum, Oakley become famous in 1953 for exposing the 'Piltdown Man' forgery.

"A skull had been "unearthed" in 1912, in Piltdown, England, and had for decades been said to represent the "missing link" in human evolution. Oakley developed a method, based on a French minerologist's theory that bones would gradually absorb fluorine from surrounding soil, to measure the fluorine levels in bones. With this and other tests he proved the bones to be a modern human braincase and an orangutan jawbone chemically stained to appear ancient. image

Created This Day: The American Museum of Natural History

In 1869, the American Museum of Natural History in New York City was officially created with the signing of a bill by the Governor of New York, John Thompson Hoffman.

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The museum began from the efforts of Albert Smith Bickmore, one-time student of Harvard zoologist Louis Agassiz, who was successful in his proposal to create a natural history museum in New York City, with the support of William E. Dodge, Jr., Theodore Roosevelt, Sr., Joseph Choate, and J. Pierpont Morgan. It opened to the public 27 Apr 1871.

With a series of exhibits, the Museum’s collection went on view for the first time in the Central Park Arsenal, the Museum’s original home, on the eastern side of Central Park.

Also, on this day in 1930, Hostess Twinkies were invented by bakery executive James Dewar.

From Today in Science History.

Born This Day: James Watson

From Today In Science History:

Watson was born on this day in 1928. An American geneticist and biophysicist, he shared the 1962 Nobel Prize for Physiology or Medicine (with Francis Crick and Maurice Wilkins) for the discovery of "the molecular structure of nucleic acids and its significance for information transfer in living material." Deoxyribonucleic acid (DNA) is the substance contained in cells that controls heredity.

Crick and Watson began their collaboration in 1951, and published their paper on the double helix structure on 2 Apr 1953 in Nature. This accomplishment became a cornerstone of genetics and was widely regarded as one of the most important discoveries of 20th-century biology.
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Premiered This Day: One Million B.C.

Directed by Hal Roach, and starring Victor Mature, Carole Landis, and Lon Chaney, Jr., this film is noted for its lizards dressed up as dinosaurs, and as being the inspiration for the better known 1967 version starring Raquel Welch.