Saturday, January 30, 2010

Published Today (1868): Darwin’s ‘Variation’

From Today In Science History:

In 1868, Charles Darwin's book - Variation of Animals and Plants under Domestication - was published. He was 58. It is probably the second in importance of all his works. This was a follow-up work, written in response to criticisms that his theory of evolution was unsubstantiated. Darwin here supports his views via analysis of various aspects of plant and animal life, including an inventory of varieties and their physical and behavioral characteristics, and an investigation of the impact of a species' surrounding environment and the effect of both natural and forced changes in this environment.

Friday, January 29, 2010

Dr. Scott + Kids = Dino Pandemonium!



This is the scene right now in the Dino Hall of the CMNH. Kids and their parents are lined up out the door to meet Dr. Scott!

That's Scott at the left signing autographs.

Tonight at the CMNH: Paleontologist Dr. Scott Sampson



Join is tonight at 7:30 pm the Cleveland Museum of Natural History for a talk by paleontologist Scott Samspon from the Utah Museum of Natural History, entitled, “The Dinosaurs of West America: Life, Death and Evolution on an Island Continent

About 100 million years ago, central North America was flooded by the north-south oriented Cretaceous Interior Seaway. Adjacent to this warm, shallow sea, the isolated western landmass informally known as “West America” witnessed a stunning florescence of dinosaurs, from horned, duck-billed and armored plant-eaters to meat-eating tyrannosaurs and smaller raptor-like predators. Dr.Sampson has done extensive research in this region exploring the questions of giant dinosaur co-existence, the evolution of Tyrannosaurus rex and the great extinction of dinosaurs at the end of the Mesozoic Era. This program is in conjunction with the current exhibit Dinosaurs: Ancient Fossils, New Discoveries.

Many of you (or your kids) will know “Dr. Scott” as the host of the hit PBS show, “Dinosaur Train.”

Scott will be signing copies of his new book, “Dinosaur Odyssey”, after the presentation. All books are available for purchase in the Museum Store

We are expecting a sold out auditorium so please call the box office for information on ticket availability: (216) 231-1177 or 800-317-9155, ext. 3279

Thursday, January 28, 2010

Born This Day: Father of Java Man

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.


Skull cap (Trinil 2, holotype of Home erectus) from HERE.

Wednesday, January 27, 2010

Dinosaur's True Colours Revealed

Fossilized melanosomes and the colour of Cretaceous dinosaurs and birds. 2010. F. Zhang, et al. Nature, published online 27 January.


Image courtesy Chuang Zhao and Lida Xing
Abstract: Spectacular fossils from the Early Cretaceous Jehol Group of northeastern China have greatly expanded our knowledge of the diversity and palaeobiology of dinosaurs and early birds, and contributed to our understanding of the origin of birds, of flight, and of feathers.

Pennaceous (vaned) feathers and integumentary filaments are preserved in birds and non-avian theropod dinosaurs, but little is known of their microstructure. Here we report that melanosomes (colour-bearing organelles) are not only preserved in the pennaceous feathers of early birds, but also in an identical manner in integumentary filaments of non-avian dinosaurs, thus refuting recent claims that the filaments are partially decayed dermal collagen fibres.

Examples (below) of both eumelanosomes (left) and phaeomelanosomes (right) have been identified, and they are often preserved in life position within the structure of partially degraded feathers and filaments.


Image: University of Bristol
Furthermore, the data here provide empirical evidence for reconstructing the colours and colour patterning of these extinct birds and theropod dinosaurs: for example, the dark-coloured stripes on the tail of the theropod dinosaur Sinosauropteryx can reasonably be inferred to have exhibited chestnut to reddish-brown tones. press release

Died This Day: Adam Sedgwick

From Today In Science History:

Sedgwich (March 22, 1785 - Jan. 27, 1873) was an English geologist who first applied the name Cambrian to the geologic period of time, now dated at 570 to 505 million years ago. In 1818 he became Woodwardian Professor of Geology at Cambridge, holding a chair that had been endowed ninety years before by the natural historian John Woodward.

He lacked formal training in geology, but he quickly became an active researcher in geology and paleontology. Many years after Sedgwick's death, the geological museum at Cambridge was renamed the Sedgwick Museum of Geology in his honor. The museum is now part of the Department of Earth Sciences at Cambridge University.

Tuesday, January 26, 2010

Kevin Aulenback Interview

Last week author Kevin Aulenback was interviewed on the CKUA show, Bookmark, about his new book, Identification Guide to the Fossil Plants of the Horseshoe Canyon Formation of Drumheller, Alberta.

You can listen to a podcast of the show by going HERE (WMA format). I think that Kevin is in the second half of the show.

Microraptor A Glider

Model tests of gliding with different hindwing configurations in the four-winged dromaeosaurid Microraptor gui. 2010. D.E. Alexander et al. PNAS, published online before print January 25.


Credit: University of Kansas
A new flight model based on casts of the original bones and the preserved impressions of feathers of Microraptor support the argument that flight originated with ‘tree-down’ gliders.
The fossils also show that an essentially sprawling posture was a plausible hind-limb wing position to provide stable flight with gliding parameters better than those of modern "flying lemurs."

The competing "biplane posture" advanced by other researchers suggested that an upright stance provided for successful glides. But the research team argues that this stance required an impossibly heavy head to maintain a proper center of gravity. Furthermore, the presence of seven-inch-long flight feathers on the feet would prohibit any extended stay on the ground. Thus, Microraptor must have been completely arboreal.

"We decided that we would take the skeleton we had, put wings on it from the feather pattern and show that it could fly," said Burnham. "If others think that it was a terrestrial runner, they should make a model and put it on a treadmill and show that it could run with those long feathers on its hind legs."

Successful flight tests were conducted in the open air and under more controlled conditions at KU. A video of some of the tests is available HERE

Indeed, the team's work provides such strong support for the trees-down model for the origin of avian flight that the alternative terrestrial (ground up) origin now may be abandoned [right – good luck with that! Ed.]. link

Born This Day: Roy Chapman Andrews


Photo from Parade of Life Through The Ages, by Charles Knight, Nat. Geo., Feb. 1942.

From the American Museum of Natural History web site:

Adventurer, administrator, and Museum promoterAndrews (Jan. 26, 1884 – March 11, 1960) spent his entire career at the American Museum of Natural History, where he rose through the ranks from departmental assistant, to expedition organizer, to Museum director.

He became world famous as leader of the Central Asiatic Expeditions, a series of expeditions to Mongolia that collected, among other things, dinosaur eggs. Although on these expeditions, Andrews himself found few fossils, and during his career he was not known as an influential scientist, he instead filled the role of promoter, creating immense excitement and successfully advancing the research and exhibition goals of the museum.

Learn about the Roy Chapman Andrews Society HERE.

Monday, January 25, 2010

Born This Day: Theodosius Dobzhansky

Dobzhansky (Jan.25, 1900–Dec. 18, 1975) is noted for being one of the architects of the modern Synthetic Theory of evolution. During the first 20 years of the 20th century, Darwin's theory of natural selection had fallen out of favor among scientists. Many thought it insufficient to explain the origin of adaptations, while new discoveries of gene mutations seemed to them to be incompatible with Darwinian models of change.

But in 1937 Dobzhansky published his book, Genetics and the Origin of Species, that was the first systematic overview view encompassing organic diversity, variation in natural populations, selection, isolating mechanisms (a term he coined) and species as natural units.

Later, working with Sewall Wright, he went on to demonstrate how evolution can produce stability and equilibrium in populations rather than constant directional change. link. image.

Tetsuto Miyashita



"Tetsuto Miyashita was given a book about dinosaurs by Dr. Philip Currie, right, when he was a 10-year-old in Japan. Now he is studying for his master's under Currie and Eva Koppelhus".

Tetsuto’s been featured on the blog a number of times for his work with me in southern Alberta.

Read the full story at the Edmonton Journal and watch the video

Sunday, January 24, 2010

Premiered This Day (1956): The Animal World

“2 Billion Years in the Making!”


Produced and directed by Irwin Allen, whose long career included such TV hits as Lost In Space and Voyage To The Bottom Of The Sea, and movies like The Poseidon Adventure and The Towering Inferno.

The Animal World was one of the first films to present dinosaurs in the quasi-nature documentary so beloved by the Discovery Channel today. Rarely seen now, it featured about 10 minutes of great dinosaur stop-animation by Ray Harryhausen with Willis O’Brien. The entire sequence was released as an extra on the 2003 DVD release of The Black Scorpion.

Sunday T. rex

Saturday, January 23, 2010

Reviews: New William Stout Books

Title: New Dinosaur Discoveries A-Z
Author: William Stout
Publishing Information: Flesk Publications; HC; 64 pages; 1st edition $14.95
Ordering Number: ISBN: 978-1-933865-23-2
Review copy: complimentary
Read the publisher blurb
Order Here


Author: William Stout
Publishing Information: Flesk Publications; SC; 144 pages; 1st edition $24.95
Ordering Numbers: ISBN: 978-1-933865-22-5 (SC); ISBN: 978-1-933865-21-8 (HC with jacket)
Review copy: complimentary
Read the publisher blurb
Order Here


Reviews:
Dinosaur Discoveries and New Dinosaur Discoveries A-Z are the latest dinosaur books by Bill Stout whose art has been featured many times on the blog. Most dino enthusiasts will remember Bill’s The Dinosaurs–A Fantastic New View of a Lost Era first published in 1984, and later updated with new art and republished in 2000 as The New Dinosaurs. More recently Flesk Publications produced William Stout: Prehistoric Life Murals featuring Bill's murals for the Houston Museum of Natural Science, Walt Disney World's Animal Kingdom, and the San Diego Natural History Museum.

The new books feature Bill’s artistic takes on new dinosaurs named within the last decade, many of which were described and named in the last few years. Each book features a pen and ink drawing enhanced by eye-catching watercolours, with the dinosaurs depicted with either a minimalistic background and a few accurately drawn plants, or a fully rendered environment including other appropriate animals & plants. The text for each dinosaur is limited to a brief, but accurate, listing of the usual data, and short description of the dino and other pertinent facts of its discovery or anatomy.

Both books benefit from the fact that Bill is (1) an exceptional anatomist and artist, and (2) he has thoroughly researched each animal by going to the primary literature. My only complaint, and it’s a minor one, is that he has left the species name out of every description. While in most cases new genera are described, the Pachyrhinosaurus entry refers to P. lacustris, not P. canadensis, but the reader is not informed of this.

I’ve reviewed the two books together because New Dinosaur Discoveries A-Z is actually a condensed version (both in size and page number) of the larger book, featuring one dinosaur for each letter of the alphabet. All the art is taken from Dinosaur Discoveries, and it is clearly aimed at a more juvenile market.

I have to mention Flesk Publications secret weapon that makes each of these books (and all of Flesk’s recent publications) a real treat for the book lover – designer Randy Dahlk. Dahlk has a gift for designing gorgeous books that the reader will want to own no matter what the subject matter. Note that Randy’s design for New Dinosaur Discoveries A-Z turns it into a ‘Golden Book’, so fondly remembered by many older readers. For this reason alone you’ll want to pick up both books.

Recommendations: Both get the Palaeoblog’s Highest Recommendation.

Friday, January 22, 2010

Humans Killed Australian Megafauna

And Then There Were None?. 2010. R. G. Roberts & B. W. Brook. Science 327: 420-422.
New research indicates that humans, not climate change, caused the demise of Australia's megafauna - giant marsupials, huge reptiles and flightless birds - at least 40,000 years ago.

2001: A Space Odyssey © MGM. Art & Story by Jack Kirby © Marvel Comics
Improved dating methods show that humans and megafauna only co-existed for a relatively short time after people inhabited Australia, adding weight to the argument that hunting led to the extinction of large-bodied species.

One site in western NSW - Cuddie Springs - stood out as an anomaly. Fossils of super-sized kangaroos, giant birds and the rhino-sized Diprotodon (the largest marsupial ever to roam Australia) were found in the same sedimentary layers as stone tools, leading some scientists to previously claim "unequivocal evidence" of a long overlap of humans and megafauna.

New methods to directly date bones and teeth of extinct species show that megafauna fossils and Aboriginal tools do not all date from the same period- they were mixed together over many thousands of years, long after the giant animals had died.

"Given that people arrived in Australia between 60,000 and 45,000 years ago, human impact was the likely extinction driver, either through hunting or habitat disturbance," he says. link

Thursday, January 21, 2010

Dinosaur Death Pits

Dinosaur Death Pits from the Jurassic of China. 2010. D.A. Eberth, et al. Palaios 25: 112-125.


Two small Guanlong wucaii dinosaurs struggle to escape a muddy pit in what is now China during the late Jurassic period. Painting by Michael Skerpnick

ABSTRACT [edit]: Three newly discovered bonebeds from the Shishugou Formation of Xinjiang, China, are unusual in preserving vertically stacked and articulated to associated skeletons of at least 18 small, non-avian theropod dinosaurs in pits that are 1–2m deep.

There is no evidence that the pits were discrete depressions in the topography that filled through time. Rather, they appear to have been highly localized areas of liquefaction caused by large-dinosaur (possibly sauropod) trampling of saturated sediments.

Evidence indicates that the small theropods, and some other small vertebrates, became mired and died in these mud-filled pits. High quality skeletal preservation suggests that most individuals were buried within days to months after their deaths. Carcasses were buried successively, coming to rest above previously buried individuals.

Given the large sizes of the pits relative to the small body sizes of the vertebrates contained within them, we conclude that small vertebrates (3m long and 1 m tall) were particularly susceptible to miring at these sites.

Although the small, presumably herbivorous ceratosaur, Limusaurus inextricabilis, dominates the combined small theropod assemblage from these bonebeds, there is no evidence that any biological features other than its small size and a large, and possibly, gregarious local population were responsible for its becoming mired in large numbers.

A bias for small theropods in these bonebeds, compared to their relatively low abundance in the overall Shishugou Formation fauna, underscores that small theropods are underrepresented in Mesozoic fossil assemblages collected from other ancient alluvial and paludal settings.

Read the story at National Geographic News

Wednesday, January 20, 2010

New Model For The Origin of Primates

Evolution and biogeography of primates: a new model based on molecular phylogenetics, vicariance and plate tectonics. 2009. Zoologica Scripta, Published Online: 10 Nov 2009



A new model for primate origins argues that the distributions of the major primate groups are correlated with Mesozoic tectonic features and that their respective ranges are congruent with each evolving locally from a widespread ancestor on the supercontinent of Pangea about 185 million years ago.



"According to prevailing theories, primates are supposed to have originated in a geographically small area (center of origin) from where they dispersed to other regions and continents" said Heads, who also noted that widespread misrepresentation of fossil molecular clocks estimates as maximum or actual dates of origin has led to a popular theory that primates somehow crossed the globe and even rafted across oceans to reach America and Madagascar.

In this new approach to molecular phylogenetics, vicariance, and plate tectonics, Heads shows that the distribution ranges of primates and their nearest relatives, the tree shrews and the flying lemurs, conforms to a pattern that would be expected from their having evolved from a widespread ancestor. This ancestor could have evolved into the extinct Plesiadapiformes in north America and Eurasia, the primates in central-South America, Africa, India and south East Asia, and the tree shrews and flying lemurs in South East Asia.


Detective Chimp (c) DC Comics
Divergence between strepsirrhines (lemurs and lorises) and haplorhines (tarsiers and anthropoids) is correlated with intense volcanic activity on the Lebombo Monocline in Africa about 180 million years ago. The lemurs of Madagascar diverged from their African relatives with the opening of the Mozambique Channel (160 million years ago), while New and Old World monkeys diverged with the opening of the Atlantic about 120 million years ago.

Biogeographic evidence for the Jurassic origin for primates, and the pre-Cretaceous origin of major primate groups considerably extends their divergence before the fossil record, but Heads notes that fossils only provide minimal dates for the existence of particular groups, and there are many examples of the fossil record being extended for tens of millions of years through new fossil discoveries. link

Tuesday, January 19, 2010

Died This Day: Frank Reicher

Frank Reicher (Dec. 2, 1875 - Jan. 19, 1965) was a German actor, director and producer born in Munich, Germany. During the early part of the twentieth century he was often on Broadway, occasionally in leading roles, but he is most familiar to modern audiences as a supporting character actor in films.

He is probably best known for playing Captain Englehorn in the movies King Kong and Son of Kong in 1933. link

MLK DAY at CMNH

In celebration of Martin Luther King Day yesterday, the Cleveland Museum of Natural History had free admission for the public. More than 5000 visitors came by to talk with the curators, staff and volunteers who moved out of their offices and labs and into the galleries for the day. Here are just a few images from yesterday.


Vert Paleo volunteer George explains placoderm fish.


Vert Paleo volunteer Joe describes the Nanotyrannus that got away from him.


Junior docent in training, Ryan, explains all you need to know about small tyrannosaurs.


High School volunteers Henry and Matt compare modern shark jaws to Devonian fossil jaws.


Physical Anthropology


Archaeology


Anne Sanford from the Phys. Anthro Casting Lab demonstrates facial reconstructions.


So does Dr. Linda Spurlock, Director of Human Health


Dr. Joe Hannibal and CWRU Work Study Student, Jeff, talk about rocks & invertebrate fossils.

Thanks to everyone for making this year's MLK Day a great success!

Osteology of Falcarius utahensis

Osteology of Falcarius utahensis (Dinosauria: Theropoda): characterizing the anatomy of basal therizinosaurs. 2010. L. E. Zanno. Zool. J. Linn. Soc. :196-230.



ABSTRACT [edit]: Falcarius utahensis, from the lower Yellow Cat Member of the Cedar Mountain Formation, represents the most complete and morphologically primitive therizinosaur yet discovered. This work completes the description of skeletal material prepared from the Crystal Geyser Quarry subsequent to the first five years of excavation.

Results of this study reveal a significant degree of morphological disparity between Falcarius utahensis and the evidently coeval primitive therizinosaur Beipiaosaurus inexpectus from the Yixian Formation, People's Republic of China and help characterize morphological transformations occurring in the therizinosaur lineage.

Falcarius documents that marked heterodonty – characterized by elongate, incisiform rostral teeth – is present in basal therizinosaurs and oviraptorosaurs (i.e. Incisivosaurus gauthieri, Protarchaeopteryx robusta), and either represents a synapomorphy or symplesiomorphy for these groups or an early phase in the convergent progression toward rostral endentulism. Nonetheless, heterodonty suggests that diet was a primary factor in the early evolution of both clades.

Died This Day: George Ledyard Stebbins

From the U Calif., Berkeley:

Along with Dobzhansky (1900 - 1975), animal systematist Ernst Mayr, and paleontologist George Gaylord Simpson (1902 - 1984), Stebbins (Jan. 6, 1906 - Jan. 19 2000) is considered one of the "architects" of the modern evolutionary synthesis of the 1930s and 1940s, an intellectual watershed and historic turning point that brought together research in cytology, genetics, systematics, paleontology into a common evolutionary framework.

This synthesis, which had the effect of reconciling the often opposing views of laboratory-oriented geneticists and natural history oriented systematists, made Charles Darwin's theory of evolution by natural selection the centerpiece of the new discipline of evolutionary biology.

In this role, Stebbins is credited with bringing a modern framework to the study of plant evolution, and he is perhaps best known for his book Variation and Evolution in Plants, published by Columbia University Press (NY) in 1950. In the 1940s, Stebbins also played an important role in organizing the nascent Society for the Study of Evolution, of which he became the third president in 1948, and used his position to speak out for the botanical side of evolutionary studies, a field that had been dominated by zoologists. Photo .

Monday, January 18, 2010

Developmental Palaeontology

Developmental palaeontology in synapsids: the fossil record of ontogeny in mammals and their closest relatives. 2010. M. R. Sánchez-Villagra. Proc. Roy. Soc. B. Published online before print January 13.

Abstract: The study of fossilized ontogenies in mammals is mostly restricted to postnatal and late stages of growth, but nevertheless can deliver great insights into life history and evolutionary mechanisms affecting all aspects of development.

Fossils provide evidence of developmental plasticity determined by ecological factors, as when allometric relations are modified in species which invaded a new space with a very different selection regime. This is the case of dwarfing and gigantism evolution in islands.

Skeletochronological studies are restricted to the examination of growth marks mostly in the cement and dentine of teeth and can provide absolute age estimates. These, together with dental replacement data considered in a phylogenetic context, provide life-history information such as maturation time and longevity.

Palaeohistology and dental replacement data document the more or less gradual but also convergent evolution of mammalian growth features during early synapsid evolution. Adult phenotypes of extinct mammals can inform developmental processes by showing a combination of features or levels of integration unrecorded in living species. Some adult features such as vertebral number, easily recorded in fossils, provide indirect information about somitogenesis and hox-gene expression boundaries.

Developmental palaeontology is relevant for the discourse of ecological developmental biology, an area of research where features of growth and variation are fundamental and accessible among fossil mammals.

Download the PDF HERE.

Sunday, January 17, 2010

Born This Day: August Weismann

From Today In Science History:

August (Friedrich Leopold) Weismann (Jan. 17, 1834 – Nov. 5, 1914) was a German biologist and one of the founders of the science of genetics. He is best known for his opposition to the doctrine of the inheritance of acquired traits and for his "germ plasm" theory, the forerunner of DNA theory.

Weismann conceived the idea, arising out of his early observations on the Hydrozoa, that the germ cells of animals contain "something essential for the species, something which must be carefully preserved and passed on from one generation to another."

Weismann envisioned the hereditary substances from the two parents become mixed together in the fertilized egg and a form of nuclear division in which each daughter nucleus receives only half the original ancestral germ plasms.

More info from Science World. image

Born This Day: Gaspard Bauhin

From Today In Science History:

Bauhin (Jan. 17, 1560 - Dec. 5, 1624) was a Swiss physician, anatomist, and botanist who introduced a scientific binomial system of classification to both anatomy and botany. In 1623 Bauhin produced the Pinax Theatri Botanici, the first attempt to summarize a confusing array of names. It was a monumental compilation that pulled together uncoordinated plant names and descriptions of 6000 species that had appeared in Theophrastus and Dioscorides, as well as in later herbals and other plant records.

By accepting Bauhin's compilation, Linnaeus was able to avoid many of the complications of the ancient literature.

Saturday, January 16, 2010

Born This Day: Caroline Munro


Art © Mark Schultz
Munro is probably best known for her role in in the Bond film The Spy Who Loved Me (1977). She had a long career in a variety of genre films including a stint with Hammer Films, and notably with Ray Harryhausen as the slave girl, Margiana, in The Golden Voyage of Sinbad (1974).

She takes a bow on the Palaeoblog both for being the Godmother of Harryhausen’s daughter and for her role as Princess Dia in At the Earth’s Core (1976)

Born This Day: Ruth Rose


Ruth Rose (Jan. 16, 1896 - June 8, 1978) was the daughter of Edward E. Rose. In 1926 she meet (and later married) cinematographer Ernest Schoedsack when they were both working on a New York Geological Society expedition to the Galapagos Islands. Together with partner and fellow producer director, Meriam C. Cooper, and animator Willis O’Brien, they made “King Kong”, released in 1933.

Rose shared in many of Schoedsack’s and Cooper’s wilderness film productions, and worked as a writer or script doctor on King Kong, Son of Kong, She, The Last Days of Pompeii and Mighty Joe Young.

The photo from King Kong (above) is of Bruce Cabot, Fay Wray and Robert Armstrong, but Rose clearly modeled the characters they played after Schoedsack, herself, and Cooper.

Friday, January 15, 2010

Unidirectional Airflow in the Lungs of Alligators. 2010. C. G. Farmer and K. Sanders. Science 327: 338-340.
Air flows in one direction as it loops through the lungs of alligators, just as it does in birds. The study suggests this breathing method may have helped the dinosaurs' ancestors dominate Earth after the planet's worst mass extinction 251 million years ago.
Such a breathing pattern likely evolved before 246 million years ago, when crocodilians split from the branch of the archosaur family tree that led to pterosaurs, dinosaurs and birds.


Image: C.G. Farmer & Kent Sanders, U. of Utah
Computerized tomographic (CT) X-ray images of side and top views of a 24-pound American alligator, with 3-D renderings of the bones and of airways or bronchi within the lungs. The windpipe and first-tier of bronchi are not shown. Air flows in one direction through a gator's lungs. It flows from the first-tier bronchi through second-tier bronchi (blue), then through tube-like third-tier parabronchi (not shown) and then back through other second-tier bronchi (forest green).
This means that one-way airflow evolved in archosaurs earlier than once thought, and may explain why those animals came to dominance in the Early Triassic Period, after the extinction and when the recovering ecosystem was warm and dry, with oxygen levels perhaps as low as 12 percent of the air compared with 21 percent today.

Farmer emphasized the discovery does not explain why dinosaurs, which first arose roughly 230 million years ago, eventually outcompeted other archosaurs.

Died This Day: Jean-Baptiste-Julien d' Omalius d'Halloy

d'Halloy (Feb. 16, 1783 - Jan. 15, 1875) was a Belgian geologist who was an early proponent of evolution and was acknowledged by Charles Darwin in his preface to ‘On The Origin of the Species’ for his opinions on the origin of new species through descent with modification.

He determined the stratigraphy of the Carboniferous and other rocks in Belgium and the Rhine provinces, and also made detailed studies of the Tertiary deposits of the Paris Basin. link

Died This Day: Alpheus Hyatt

From Today in Science History:

U.S. zoologist and paleontologist who studied invertebrate fossil records, the evolution of the cephalopods (a class of mollusks including squids and octopuses) and the development of primitive organisms.

Along with E. Cope, Hyatt (April 5, 1838 - Jan. 15, 1902) was the most prominent American neo-Lamarckian. Based on the analogy of ontogeny with phylogeny, Hyatt claimed that lineages, like individuals, had cycles of youth, old age, and death (extinction). This idea became the bulwark of orthogenetic theories in the U.S. Hyatt was the founder and first editor of the American Naturalist, and first president of Woods Hole laboratory.

Opened To The Public (1759): The British Museum

On this day in 1759, the British Museum, in Bloomsbury, London, the world's oldest public national museum, opened to the public who were admitted in small groups, by ticket obtained in advance, for a conducted tour.

It was established on June 7, 1753 when King George II gave his royal assent to an Act of Parliament to acquire the collection of Sir Hans Sloane. In his will, he had offered the nation his lifetime collection of 71,000 objects, mostly plant and animal specimens. In return, he requested £20,000 for his heirs (which today would be over £2,000,000). The present museum buildings date from the mid-19th century. Its natural history collection moved to its own museum in 1881. link

Thursday, January 14, 2010

Born This Day: Father of Paleobotany

Adolphe-Théodore Brongniart (Jan. 14, 1801 - Feb. 18, 1876) was a French botanist whose classification of fossil plants drew surprisingly accurate relations between extinct and existing forms prior to Charles Darwin's principles of organic evolution. His work earned him the distinction as the founder of modern paleobotany.

He was an early proponent of evolutionary theory. Brongniart published the first complete account of fossil plants (1828). His interpretations of the fossil record also contributed to our understanding of historical changes in climates and plant geography. link image

Sunday, January 10, 2010

Born This Day: Nicolaus Steno

Steno (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

Died This Day: Carolus Linnaeus

From the Linnean Society:

Linnaeus (May 23, 1707 – Jan. 10, 1778) was born in 1707 in Sweden. He headed an expedition to Lapland in 1732, travelling 4,600 miles and crossing the Scandinavian Peninsula by foot to the Arctic Ocean. On the journey he discovered a hundred botanical species. He undertook his medical degree in 1735 in the Netherlands. In 1735, he published Systema Naturae, his classification of plants based on their sexual parts.

His method of binomial nomenclature using genus and species names was further expounded when he published Fundamenta Botanica (1736) and Classes Plantarum (1738). This system used the flower and the number and arrangements of its sexual organs of stamens and pistils to group plants into twenty-four classes which in turn are divided into orders, genera and species.

In his publications, Linnaeus provided a concise, usable survey of all the world's plants and animals as then known, about 7,700 species of plants and 4,400 species of animals. These works helped to establish and standardize the consistent binomial nomenclature for species which he introduced on a world scale for plants in 1753, and for animals in 1758, and which is used today.

His Systema Naturae 10th edition, volume 1(1758), has accordingly been accepted by international agreement as the official starting point for zoological nomenclature. Scientific names published before then have no validity unless adopted by Linnaeus or by later authors. This confers a high scientific importance on the specimens used by Linnaeus for their preparation, many of which are in his personal collections now treasured by the Linnean Society.

He was granted nobility in 1761, becoming Carl von Linné. He continued his work of classification and as a physician, and remained Rector of the University until 1772.

Saturday, January 09, 2010

Born This Day: Amadeus William Grabau

From Today In Science History:

Grabau (Jan 9, 1870 – March 20, 1946) was an American geologist and paleontologist, known for his work on world stratigraphic deposits and the deciphering of Earth history. In 1899, he published an early paper that studied the environment of old sedimentary rocks in light of knowledge of the conditions of life among modern organisms, The Relations of Marine Bionomy to Stratigraph, which was a step toward the development of paleoecology.

For more than a quarter of a century, he worked on the geologic survey of China. In 1940, he developed a theory of rhythms in the growth of the Earth's crust, and of repetitions in mountain building. image