The Stand on Sauropod Stances

This:


Or this:

Or...?

"A great deal of scientific, financial, and political clout had been invested in the Carnegie sauropods, and eventually the criticisms became too much to bear. Here, The HMNH Library proudly presents the final argument in this tale—an authoritative, well illustrated smackdown of the sprawling sauropod hypothesis presented by no less a figure than the director of the Carnegie Museum of Natural History, Dr. William J. Holland."

Go HERE to read it all. (Note—the top part of the page is blank on my browser so be sure to scroll down!)

Thanks to the head’s up on this from Dr. Eric Snively, the man the Palaeoblog goes to for all our tyrannosaurid questions.

Visit the

The Hairy Museum of Natual History

Plastic Dinosaurs

I’ve pointed these out before but it’s worth repeating. These are some of the nicest plastic dinosaur models available. They’re both huge—the Albertosaurus is over 18 inches long—and make great desktop show pieces.

You can buy them HERE for $12 (US) each.



Which reminds me that the ever efficient U of Alberta PR dept. sent out THIS release about the palaeos there ponying up to buy the below cast of the holotype Styracosaurus skull at the recent SVP auction. This picture shows it at the RCI shop where it was produced.

Born This Day: Sir Charles Lyell

Nov. 14, 1797 - Feb. 22, 1875



From Minnesota State University at Mankato comes this excellent bio on Lyell:

Sir Charles Lyell attended Oxford University at age 19. Lyell's father was an active naturalist. Lyell had access to an elaborate library including subjects such as Geology.

When Lyell was at Oxford, his interests were mathematics, classics, law and geology. He attended a lecture by William Buckland that triggered his enthusiasm for geology. Lyell originally started his career as a lawyer, but later turned to geology. He became an author of The Geological Evidence of the Antiquity of Man in 1863 and Principles of Geology. Lyell argued in this book that, at the time, presently observable geological processes were adequate to explain geological history. He thought the action of the rain, sea, volcanoes and earthquakes explained the geological history of more ancient times.

Lyell rebelled against the prevailing theories of geology of the time. He thought the theories were biased, based on the interpretation of Genesis. He thought it would be more practical to exclude sudden geological catastrophes to vouch for fossil remains of extinct species and believed it was necessary to create a vast time scale for Earth's history. This concept was called Uniformitarianism. The second edition of Principles of Geology introduced new ideas regarding metamorphic rocks. It described rock changes due to high temperature in sedimentary rocks adjacent to igneous rocks. His third volume dealt with paleontology and stratigraphy. Lyell stressed that the antiquity of human species was far beyond the accepted theories of that time.

Charles Darwin became his dear friend and correspondent. Darwin is quoted saying, "The greatest merit of the Principles was that it altered the whole tone of one's mind, and therefore that, when seeing a thing never seen by Lyell, one yet saw it through his eyes."

Image from King’s College London.

Hot Times For Male Tuataras

Less than one degree Celsius is all that stands between the tuatara—New Zealand's "living fossil" reptile—and extinction, scientists say.

From National Geographic News:

The sex of tuatara—the sole surviving species of an ancient family of reptiles dating back 200 million years—is determined by the incubation temperature of its eggs. As the mercury climbs, so does the proportion of male hatchlings.

The mechanism is so delicate that a flagging population on remote North Brother Island in Cook Strait is already running short of breeding females. Nicky Nelson, a senior lecturer at Victoria University in Wellington, New Zealand, says experiments show that 21.7 degrees could be the pivotal temperature.

"At 22 degrees Celsius, we got 100 percent males. At 21 degrees Celsius, we got three males out of 80 eggs," Nelson said.

Intensifying the problem is the slow reproduction rate of the reptiles. On average, female tuatara mate once every four years, and eggs take between 11 and 16 months to hatch.

Tuatara have endured climatic chaos before, Nelson says—they even survived the meteor strike many believe wiped out the dinosaurs. But the reptiles were far more abundant back then, bestowing them with enough genetic diversity to see them through the global catastrophe, Nelson says. Now, with their numbers already decimated [decimate actually means to decrease by 10%--PBlog], the species may face a much faster rate of warming.

So scientists are gathering eggs and raising them in artificial incubators.
"We can dial in whichever sex we like," Nelson said.

Hatchlings are reared in captivity before being introduced to other islands as part of an effort by New Zealand's Department of Conservation to reintroduce the tuatara to its former haunts.

Born This Day: Gustav Heinrich Ralph Von Koenigswald

Nov. 13, 1902- Nov. 9, 1982

German paleontologist and geologist G.H. Ralph von Koenigswald is best known for his work on early primate ancestors of humans, such as Pithecanthropus, Giganopithicus blacki, and Hemanthropus. He spent most of his career doing fieldwork in Java. He was also associated with the Netherlands Geological Survey and the Carnegie Foundation and taught at the Rijksuniversiteit in Utrecht.

Like many palaeontologists, Koenigswald had an interesting life. Russell L. Ciochon gives this story from HERE:

“The original fossils of Peking man disappeared during the confusion of World War II - fortunately, after they were described and cast by anatomist Franz Weidenreich. The war also caught up with von Koenigswald, who was taken prisoner by the Japanese in Java. His precious collection of Gigantopithecus teeth - at that point, the only known specimens of the fossil ape - spent the war years in a milk bottle buried in a friend's backyard on the island”.

Info. Image. More information.

Write Your Name In Hieroglyphics

It’s not palaeo but its fun. That’s supposed to say “palaeoblog”.

Try it yourself at HERE. Thanks to Neatorama

Dietary Variation In Pananthropus

Isotopic Evidence for Dietary Variability in the Early Hominin Paranthropus robustus. 2006. M. Sponheimer et al. Science 314: 980 – 982.


Paranthropus in southern Africa 1 million years ago. Artwork by W. Voigt.

Abstract: Traditional methods of dietary reconstruction do not allow the investigation of dietary variability within the lifetimes of individual hominins. However, laser ablation stable isotope analysis reveals that the ∂¹³ C values of P. robustus individuals often changed seasonally and interannually.
These data suggest that Paranthropus was not a dietary specialist and that by about 1.8 million years ago, savanna-based foods such as grasses or sedges or animals eating these foods made up an important but highly variable part of its diet.

Paranthropus robustus skull from Swartkrans Cave, South Africa. Image courtesy D. DeRuiter, Texas A&M U.

Read the press release.

The Beast From 20,000 Fathoms

Will Science Unleash the Fearsome Forces of The Lost World!?

You Bet! Just Watch!

Half Man-Half Sea Urchin!

The Genome of the Sea Urchin Strongylocentrotus purpuratus. 2006. Sea Urchin Genome Sequencing Consortium, et al. Science 314: 941 – 952.

The Sea Urchin Genome Sequencing Project (SUGSP) Consortium, announced today the decoding and analysis of the genome sequence of the sea urchin, S. purpuratus. It contains over 814 million letters, spelling out 23,300 genes.

From the press release:

Sea urchins are echinoderms, marine animals that originated over 540 million years ago and include starfish, brittle stars, sea lilies, and sea cucumbers. The purple sea urchin emerged in the North Pacific Ocean during a rapid burst of speciation and diversification 15-20 million years ag

Although invertebrate sea urchins have a radically different morphology from humans and other vertebrates, their embryonic development displays basic similarities.

Some of the notable discoveries in sea urchins are:

- they have most of the same gene families found in man.

- their immunity system gene branch has 10 to 20 times as many genes as in humans.

- they have genes for sensory proteins that are involved in vision and hearing in man yet the sea urchin has no eyes and ears.

"The sea urchin reminds us of the underlying unity of all life on earth," notes Sodergren, co-leader of the project. "It is a similar set of genes and proteins being reused in different ways, different numbers, and at different times in the life cycle to create the diversity of living forms."


Images link & link

Watch the Video/Slide Show HERE.

Scleral Ossicles in Teleost

Skeletal elements within teleost eyes and a discussion of their homology. 2006. Tamara A. Franz-Odendaal and Brian K. Hall. Journal of Morphology 267: 1326 – 1337.

Abstract [edit]: Some vertebrates, including all birds and most reptiles, but excluding most mammals, have scleral cartilages as well as scleral ossicles supporting their eyes. The teleost equivalent of these elements has received little attention in the literature.

From radiographic and whole-mount analyses of over 400 individuals from 376 teleost species, we conclude that the teleost scleral skeletal elements (ossicles and cartilage) differ significantly from those of reptiles (including birds). Scleral ossicles in teleosts have different developmental origins, different positions within the eyeball, and different relationships with the scleral cartilaginous element than those in reptiles.

From whole-mount staining of a growth series of four species of teleost (Danio rerio, Salmo salar, Esox lucius, and Alosa pseudoharengus), we interpret the development of these elements and show that they arise from within an Alcian blue-staining cartilaginous ring that develops around the eye earlier in development. We present possible scenarios on the evolution of these scleral skeletal elements from a common gnathostome ancestor, and consider that teleost scleral skeletal elements may not be homologous to those in reptiles. Our study indicates that homology cannot be assumed for these elements, despite the fact that they share the same name, scleral ossicles. Korak

Dr. Franz-Odendaal will be visiting the CMNH Collections to continue her research on scleral ossicles in fossil fish.

Died This Day: Gideon Mantell

Feb. 3, 1790 – Nov. 10, 1852

Mantell, 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.

New Book on Zdenĕk Burian

An extensive illustrated full-color monograph by Vladimir Prokop of the work of Zdenĕk Burian (1905-1981) is now available. This book is the first detailed study of Burian's entire work encompassing various genres, and is filled with colour paintings never before collected.

This also covers his work as a book and magazine illustrator (some fine action/adventure work, including 20,000 Leagues under the Sea), his important paleontological reconstructions and ethnographic portraits, and his lesser-known uncommissioned works. Over 500 color reproductions, documentary photographs and a detailed list of all his known works. Text entirely in Czech except for a two-page overview in English. Import. Gallery, 2005 HC, 9x11, 264pg, FC.

The book is available HERE but also check with your favourite local bookseller.

In other Palaeo Art Book news, I was speaking with Charles Knight’s granddaughter this morning and she tells me that a large coffee-table book on Knight’s art is in production.

Phil Currie Wins 2006 ASTech Award

Phil & Eva at the site of the 1960's Polish-Mongolian Expedition camp at Ultan Ula IV in Mongolia last Sept.Photo © M. Ryan.

Congratulations to Dr. Philip Currie who was the recipient of the 2006 Outstanding Leadership in Alberta Science Award from the Alberta Science and Technology (ASTech) Leadership Foundation.

More Sue™ Photos

Sue is now installed and (almost) ready for her "Members Sneak Peek" tonight. I'll be giving a talk on the big critter at 6pm as part of the event.


VP volunteer Nicole helps out.


VP Casting Tech David Chapman also helps.

The Return of Carl Buell

Thanks to Sukie for pointing out the Olduvai George is back posting again.

Osteoderm Morphology & Development

Osteoderm morphology and development in the nine-banded armadillo, Dasypus novemcinctus (Mammalia, Xenarthra, Cingulata). 2006. Matthew K. Vickaryous and Brian K. Hall. Journal of Morphology 267: 1273 – 1283

Matt wrote the chapter on Ankylosauria in the latest edition of The Dinosauria. He's thought more about the development of ankylosaur dermal armour than anyone else I know, and this paper should be of interest to anyone curious about dinosaur osteoderms.

Abstract (edit): Among modern mammals, armadillos (Xenarthra, Cingulata) are the only group that possesses osteoderms, bony inclusions within the integument.

Compared with the rest of the skeleton, osteoderms have a delayed onset of development. Skeletogenesis begins as condensations of osteoblasts secreting osteoid, localized within the papillary layer of the dermis.

Osteoderm formation is asynchronous both within each shield and across the body. The first osteoderms to mineralize are situated within the pectoral shield of the carapace, followed by elements within the banded, head, pelvic, and tail shields. In general, within each shield ossification begins craniomedially and proceeds caudally and laterally, except over the head, where the earliest elements form over the frontal and parietal bones.

The absence of cartilage precursors indicates that osteoderms are dermal elements, possibly related to the all-encompassing vertebrate dermal skeleton (exoskeleton). The mode of development of D. novemcinctus osteoderms is unlike that described for squamate osteoderms, which arise via bone metaplasia, and instead is comparable with intramembranously derived elements of the skull.

The image is from the 1964 Sinclair Dinoland booklet which I now have a copy of. I'll be posting the rest of the booklet soon.

Sue™ in Cleveland

Sue™ the T. rex will be on display at the CMNH from November 11, 2006, through April 15, 2007. Here are some photos of her assembly yesterday at the CMNH.

Cloudy Skies Rained Life

Hazy skies on early Earth could have provided a substantial source of organic material useful for emerging life on the planet.

From the press release:

Researcher have measured the organic particles produced from the kind of atmospheric gases thought to be present on early Earth. They modeled conditions measured by the Huygens probe on Saturn's moon, Titan, last year during the Cassini mission. They mimicked Titan's hazy skies by exposing methane gas to an ultraviolet lamp, then added carbon dioxide gas to the mix to see if conditions that were probably present on early Earth would produce a similar organic haze. "It turns out that organic haze can form over a wide range of methane and carbon dioxide concentrations," said Tolbert.

"This means that hazy conditions could have been present for many millions or even a billion years on Earth while life was evolving."

"We found that you can make a lot of organic material virtually out of thin air," said Trainer.

According to the study, a similar haze hanging over Earth early in its history could have supplied more than 100 million tons of organic material to the planet's surface each year. "As these particles settled out of the skies, they would have provided a global source of food for living organisms," said Trainer.

In addition to serving as a source of organic material, a haze layer over Earth could have shielded living organisms from harmful UV rays and helped to regulate Earth's early climate, according to the study.

The paper will be up shortly at the PNAS.org early editions page.

Kipling West November Calendar

Because I missed Godzilla’s birthday last Friday that’s reason enough to post this cool calendar by the talented Kipling West. That and the important music event that occurred this day back in 1975. Everybody sing, …”No future,… no future…!”

To download a larger version of this image go to the 7 Deadly Sinners site.

Rhino Horns Explained

Structure of white rhinoceros (Ceratotherium simum) horn investigated by X-ray computed tomography and histology with implications for growth and external form. 2006. Tobin L. Hieronymus et al. Journal of Morphology 267: 1172 – 1176.

New research from the Witmer Lab explains how the horn gets its distinctive curve and sharply pointed tip.

From the Ohio U press release:

The horns of most animals have a bony core covered by a thin sheath of keratin, the same substance as hair and nails. Rhino horns are unique, however, because they are composed entirely of keratin. Scientists had been puzzled by the difference, but the new study has revealed an interesting clue: dark patches running through the center of the horns.

Researchers conducted CT scans on the horns and found dense mineral deposits made of calcium and melanin in the middle.



The calcium deposits make the horn core harder and stronger, and the melanin protects the core from breakdown by the sun’s UV rays, the scientists report. The softer outer portion of the horn weakens with sun exposure and is worn into its distinctive shape through horn clashing and by being rubbed on the ground and vegetation.

The study also ends speculation that the horn was simply a clump of modified hair.

“The horns most closely resemble the structure of horses’ hoofs, turtle beaks and cockatoo bills” said Tobin Hieronymus, lead author on the study.

Download the PDF HERE

Visit the Witmer Lab page for more info on Rhinoceros Horn Growth & Form.

Rhino Statue from Bowen Designs

Died This Day: Henry Fairfield Osborn

August 8, 1857 - November 6, 1935

Osborn graduated at Princeton in 1877 and pursued his interest in the biological sciences and paleontology through additional study at several New York City medical schools and with Thomas Henry Huxley in Britain. Returning to the United States, Osborn accepted a position at Princeton, teaching natural sciences from 1881 until 1891, when he moved to Columbia University to organize the Biology Department there, and in 1891, he also helped to organize the Department of Vertebrate Paleontology at the American Museum of Natural History acting as it’s first curator. Osborn's close association with American Museum continued for over 45 years, and included a long tenure as its President, 1908-1933. During these years the museum's collections expanded enormously and it became one of the preeminent research institutions for natural history in the world.

Osborn is noted for describing and naming both Tyrannosaurus rex and Albertosaurus in 1905, Pentaceratops in 1923, and Velociraptor in 1924. One of Osborn's favorite groups for study was the brontotheres, and he was the first to carry out comprehensive research on them. He also wrote an influential textbook, The Age of Mammals (1910).

Apart from his own research, Osborn is perhaps best remembered for the sponsorship of the five immensely successful Central Asiatic Expeditions during the 1920's and 30's led by Roy Chapman Andrews.

Entry from HERE and HERE.

Rethinking Archaeopteryx Flight

Structure and function of hindlimb feathers in Archaeopteryx lithographica. 2006. Nick Longrich. Paleobiology 32: 417–431.


Artistic rendering of Archaeopteryx © Nick Longrich

From the Quirks & Quarks web page:

When Archaeopteryx was first discovered, it quickly became one of the most important fossils ever found. With the skeleton of a dinosaur and the feathers of a bird, it provided the first solid link between the two groups of animals. Today, the line from dinosaurs to birds is well accepted, but it doesn't mean the skeletons don't have secrets still to be revealed. Nick Longrich, a PhD student at the University of Calgary, recently uncovered one of these secrets: that Archaeopteryx had flight feathers on its back legs. This changes our picture of how these birds flew, although exactly how the back legs were involved in flight isn't clear. It does suggest, however, that birds probably developed flight coming down from the trees, rather than by jumping into the air.

I missed this when it came out so I’m getting caught up now…

Here’s the link to the Quirks & Quarks page with an audio link to Nick’s interview, or click HERE to go directly to the MP3 interview.

Visit Nick’s excellent page on Archaeopteryx and his research HERE

Evolution of Genome in Near-Real Time

Comparative genome sequencing of Escherichia coli allows observation of bacterial evolution on a laboratory timescale. 2006. C. D. Herring et al. Nature Genetics, published online: 5 November 2006

"Paleontologists look at the fossil record to study how evolution of dinosaurs and other animals occurred over millions of years, but in the case of the E. coli bacterium, new technology has given us the ability to observe evolution as it is occurring over a matter of days," said Bernhard Ø. Palsson, professor of bioengineering at UCSD. "The published genomic sequences of bacteria are like a fossil record and our experiments confirm that these genomes can change quickly as bacteria adapt to new conditions."

Palsson's team used comparative genome sequencing technology to identify evolutionary changes that occurred during the experiment in the bacterium's complete set of genes.

The researchers report that they grew E. coli in an environment that favored the emergence of mutants: the organism was fed a poorly metabolized carbon and energy source called glycerol.

After six days of growth, mutations appeared in the gene for an enzyme that initiates the process of enzymatically breaking down glycerol. Cells with mutations in the so-called glycerol kinase gene grew 20 to 60 percent faster than those without the mutation.

"This straightforward approach to the study of experimental evolution can be used as a tool for discovery and analysis, and could even be used to discover bacterial capabilities that would benefit humankind in a variety of ways," said Herring.

Darwin In The Gobi

Another stamp sheet that I picked up in Ulaanbaatar. Click the image to enlarge.

New Elasmosaur Found In Montana

Our old buddy and fellow U Calgary grad makes the news!

Pat Druckenmiller, in the collection room of MSU's Museum of the Rockies, displays the skull and lower jaw of an ancient sea monster found in central Montana. (MSU photo by Jay Thane).

From the press release:

Ken Olson of Lewistown and his son, Garrett, found the fossils in mid-August about 75 miles northeast of Lewistown. Since Horner was in Mongolia, Olson said he prepared the fossils himself and delivered them to Horner about three weeks later. Olson, a retired Lutheran pastor, has long collected fossils for the museum. Two of his best finds are the large Torosaurus skulls displayed there.

"It's a very important specimen," MSU paleontologist Jack Horner said at the Museum of the Rockies where the fossil rests in boxes. "We have been looking for it for a long, long time."

Believed to be approximately 70 million years old, its skull and lower jaw represent the first complete skull of a long-necked plesiosaur found in Montana, according to Montana State University experts. The skull is said to be one of the best specimens of its kind in North America.


A long-necked elasmosaur. (Illo courtesy of Dr. Druckenmiller).

"This critter is one of the long, ridiculously long-necked plesiosaurs," said Pat Druckenmiller, an MSU expert in marine reptile fossils. Druckenmiller, who described a new plesiosaur called Edgarosaurus from southern Montana in 2002, was part of a Norwegian expedition in August that mapped the location of several giant fossils in the Arctic. He is now an adjunct instructor in the Department of Earth Sciences at MSU.

"If the skull is 40 cm long, the neck could be seven to 10 times that length," he said.

"This is basically the first good elasmosaur (long-necked plesiosaur) skull found in Montana," Druckenmiller said. "That, of course, is really neat. In fact, I would say this is one of the top five skulls of an elasmosaur in North America."

Ebay Dino Posters

Atomic Surgery points out that www.emovieposter.com has a lot of dinosaur and related movie posters up for auction this week.

Dinosaur Park Bites The Dust

Wairarapa, New Zealand is set to lose a $30 million dinosaur theme park originally planned for the Martinborough countryside. Dinosaurs Rock owner Jackie Bush said interest is very strong from another council "further up the North Island" and they will take the park where there is most support.

In July, Dinosaurs Rock announced the "world-class" park would be situated just outside Martinborough with life-sized dinosaurs created by the special effects supremos at Weta workshop. Weta workshop will still create the dinosaurs, but now Dinosaurs Rock, owned jointly by Mrs Bush and her husband Darren, is in the early stages of talks with another council. Link

Thanks to the Digital Dream Machine Blog for the head’s up on this.

Flamingo Oddity

Cephalic vascular anatomy in flamingos (Phoenicopterus ruber) based on novel vascular injection and computed tomographic imaging analyses. 2006. Casey M. Holliday, Ryan C. Ridgely, Amy M. Balanoff, Lawrence M. Witmer. The Anatomical Record 288A: 1031-1041

With their spindly legs, long necks and bright plumage, flamingos are a curiosity of nature. Now a new discovery by a team of Ohio University researchers reveals an anatomical oddity that helps flamingos eat: erectile tissue.

From the Ohio U press release:

Flamingos are known for their peculiar feeding behavior. While standing in shallow water, they bend their necks, tilt their bills upside down in the water and swish their heads from side-to-side. Their large tongue acts like a piston, sucking water into the front of the bill and then pushing it out the sides. Fringed plates on the tongue trap algae and crustaceans in the circulating water.

“The flamingos’ feeding habits have captured people’s curiosity for ages, but that wasn’t the original focus of our research,” said Casey Holliday, who recently earned a doctorate in biological sciences from Ohio University and served as lead author on the study. “We were investigating the evolution of jaw muscles in lizards, birds and dinosaurs. By sheer luck we discovered something new about flamingos.”

A 3-D view of the bird’s head was created using a new computed tomography (CT) scanning technique developed by the Ohio U team that highlights blood vessel anatomy. The researchers noticed large oval masses of erectile tissue located on the floor of the mouth on either side of the tongue.

“No one ever anticipated finding something like this, and now we’re scratching our heads trying to understand the role these tissues play,” said Lawrence Witmer, a professor of anatomy in Ohio U’s College of Osteopathic Medicine who directed the study.

Larry has this to add, "The project was done as part of a routine vascular injection study to provide information that feeds into several of our fossil archosaur projects. It also has other paleo tie-ins because we found osteological correlates that might inform us about evolution of similar structure in other animals."

Click HERE to go to the Witmer Lab’s “Vascular Anatomy In Flamingos” page for more information and some cool CT animation video.

Readers up in Canada will be able to see a piece next week on “Daily Planet” (Discovery Channel Canada) all about this story.

New Phylum Discovered; Brains Paraphyletic?

Deuterostome phylogeny reveals monophyletic chordates and the new phylum Xenoturbellida. 2006. Sarah J. Bourlat et al. Nature 444 85-88.

Genetic analysis of an obscure, worm-like creature retrieved from the depths of the North Atlantic has led to the discovery of a new phylum.

From the U Florida press release:

Scientists have long been puzzled by the half-inch-long Xenoturbella first retrieved from the Baltic Sea more than 50 years ago. Early genetic research identified it as a type of mollusk but more precise genomic sequencing showed that Xenoturbella belongs to its own phylum.

It is one of only about 32 such phyla in the animal kingdom. "During the last 50 to 60 years, only a few new phyla have been established," Moroz said.

Perhaps more significant, the analysis of Xenoturbella seems to confirm that human beings and other chordates share a common ancestor. Its extreme characteristics suggest that this common ancestor – one the creature shares with its sister phyla, echinoderms and hemichordates, as well as chordates -- did not have a brain or central nervous system.

A reconstructed genetic record reported in the article also implies that the brain might have been independently evolved more than twice in different animal lineages, Moroz said. This conclusion sharply contrasts the widely accepted view that the centralized brain has a single origin.

SVP 2006 Photos

Do you recognize these characters? I do!

The photos were taken by ReBecca Hunt who has a large assortment of pictures from the 2006 Society of Vertebrate Paleontology conference in Ottawa up at www.dinochick.com. Go check 'em out now!

The Elephant's Missing Link

A pig-sized, tusked creature that roamed the earth some 27 million years ago represents a missing link between the oldest known relatives of elephants and the more recent group from which modern elephants descended.

The teeth of the newly described Eritreum melakeghebrekristosi.

From the U of Michigan press release:

The group's findings, to be published this week in the Proceedings of the National Academy of Sciences, suggest that mastodons and the ancestors of elephants originated in Africa, in contrast to mammals such as rhinos, giraffes and antelopes, which had their origins in Europe and Asia and migrated into Africa. The dating of the new fossil, discovered in the East African country of Eritrea, also pushes the origins of elephants and mastodons five million years farther into the past than previous records, said Martin Sanders, lead author.


Image Link

After 25 million years ago, larger proboscideans such as mastodons and gomphotheres—the ancestors of modern elephants—dominated the scene. Elephant-sized, with long tusks and trunks, these advanced proboscidans had more complex teeth that emerged more slowly, so that each quadrant of the mouth had only one or two functional teeth in place at a time.

"The new fossil from Eritrea is important because it shows aspects of dental anatomy in common with the advanced group, including molars with more cusps and complex crowns and the delayed maturation and emergence of molars," said Sanders. But the new fossil also has characteristics in common with palaeomastodonts, namely smaller body size and a jaw structure that suggests shorter tusks and trunk.

Whay Are There More Species In The Tropics?

Evolutionary and Ecological Causes of the Latitudinal Diversity Gradient in Hylid Frogs: Treefrog Trees Unearth the Roots of High Tropical Diversity. 2006. John J. Wiens et al. The American Naturalist 168: 579-596.

From thr U Chicago press release:

In a paper appearing in the November issue of The American Naturalist, John Wiens and a group of researchers have shown that, contrary to expectations, species seem to evolve at similar rates in tropical and temperate regions. What causes the difference in species numbers between tropical and temperate regions is not something special about the tropics that leads to more rapid speciation, but rather that the temperate areas were colonized more recently, leaving less time for species to originate and accumulate in these regions.

The researchers studied the causes of high tropical species richness in treefrogs in the Americas. Combining analyses of evolutionary trees based on DNA sequences with GIS-based methods for analyzing the effects of climate on species distributions, the researchers found no relationship between how quickly species originate within a group and whether that group is tropical or temperate.

However, they did find a strong relationship between when each region was colonized and the number of species there today. Thus, the high species richness of tropical regions seems to be explained by the ancient origin of many groups in the tropics, more recent colonization of temperate regions, and by the inability of most tropical species to tolerate the variable temperatures of temperate areas. Image Link

5 Million Year Old Retrovirus Reanimated

A team of scientists has reconstructed the DNA sequence of a 5-million-year-old retrovirus and shown that it is able to produce infectious particles.

From the press release:

The retrovirus--named Phoenix--is the ancestor of a large family of mobile DNA elements, some of which may play a role in cancer. The study, which is the first to generate an infectious retrovirus from a mobile element in the human genome, is considered a breakthrough for the field of retrovirus research. The findings are reported in Genome Research.

"Phoenix became frozen in time after it integrated into the human genome about 5 million years ago," explains Dr. Thierry Heidmann, lead investigator on the project. "In our study, we've recovered this ancestral state and shown that it has the potential for infectivity."

Retroviruses, whose genomes consist of RNA, can create DNA "copies" of the RNA genomes and incorporate them into the genomes of their hosts. Phoenix belongs to a sub-category of retroviruses--known as HERVs (human endogenous retroviruses)--which inserted copies into the human germline millions of years ago. Remnants of HERVs now comprise nearly 8% of the human genome, but most were rendered inactive long ago by mutations.