Nigersaurus

Structural Extremes in a Cretaceous Dinosaur. 2007. Sereno PC, Wilson JA, Witmer, LM. et al. PLoS ONE 2(11): e1230.



From the press release:

Nigersaurus, a younger cousin of the more familiar North American dinosaur Diplodocus, is small for a sauropod, measuring only 30 feet in length. It managed to sustain its elephant-sized body with a featherweight skull armed with hundreds of needle-shaped teeth, said Sereno. Barely able to lift its head above its back, Nigersaurus operated more like a Mesozoic cow than a reptilian giraffe, mowing down mouthfuls of greenery that consisted largely of ferns and horsetails.

The dinosaur’s oddest feature was a broad, straight-edged muzzle, which allowed its mouth to work close to the ground. Unlike any other plant eater, Nigersaurus had more than 50 columns of teeth, all lined up tightly along the front edge of its squared-off jaw, forming, in effect, a foot-long pair of scissors.

“Some of these unusual sauropods thrived to become the pre-eminent ground-level feeders of the Mesozoic,” said coauthor Jeffrey Wilson, assistant professor at the University of Michigan.



Coauthor Lawrence Witmer, professor at Ohio University, who imaged the brain and organ of equilibrium, said, “What we have here is the first good look at a sauropod brain, and it has important things to say about this animal’s posture and behavior.”

See also the cover article in the December 2007 issue of National Geographic magazine, “Extreme Dinosaurs.”

A Dino In ROM's Attic

Image © Michael Skrepnick, done especially for the ROM

From the Toronto Star:

For its permanent exhibition opening Dec. 15 in the new Crystal wing, the Royal Ontario Museum (ROM) wanted a sauropod – one of the huge, long-necked, lumbering creatures that unmistakably says "dinosaur."

The job of finding one went to Dr. David Evans, 27, associate curator of vertebrate paleontology. He found a bunch of miscellaneous dinosaur bones scattered throughout the ROM collection. Some were in drawers. Some were in shelves over here, some in shelves over there.

"I saw half an arm bone in a drawer and 25 feet away there was the other half. I picked it up, walked it over and stuck it on the end. Wow!

Evans pieced together one of only six Barosaurus skeletons known to exist. Of them, the ROM's is the second most complete, with more than 1,000 fossilized pieces. One lay before Evans as he spoke, a fossilized thigh bone weighing 150 kilograms.

The bones were acquired in 1962 from Pittsburgh's Carnegie Museum of Natural History by ROM curator Gordon "Gordo" Edmunds. He planned to mount them in 1970. That didn't happen. He retired and later died, and the story of the bones might have died with him if not for Evans's chance reading.

"We're naming the skeleton `Gordo' in the late curator's honour," ROM director William Thorsell told reporters. "`Gordo' means `fat' in Spanish, which also works."

New York's American Museum of Natural History holds the most complete Barosaurus skeleton. The ROM's will rank as Canada's largest dinosaur on display. Pieces the museum doesn't have will be cast.

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.

Born This Day: Father of the Devonian Period

Painting by Dan Erickson of the Phaeton Group

William Lonsdale (Sept. 9, 1794 – Nov. 11, 1891 ) was an English geologist and paleontologist whose study of coral fossils found in Devon, suggested (1837) certain of them were intermediate between those typical of the older Silurian System (408 to 438 Ma) and those of the later Carboniferous System (286 to 360 Ma. Geologists Roderick Murchison and Adam Sedgwick agreed and named this new geologic system after its locale - the Devonian Period (1839).

Lonsdale's early career was as an army officer (1812-15) and later he became curator and librarian of the Geological Society of London (1829-42). He recognised that fossils showed how species changed over time, and more primitive organisms are found in lower strata.
From Today In Science History

First Land Animals Saw In Colour

Visual pigments in a living fossil, the Australian lungfish Neoceratodus forsteri. 2007. Helena J Bailes, et al. Evolutionary Biology 7: 200.

According to a new study it's likely that creatures venturing out of the depths viewed their new environment in full colour.

A team analysed retinas from Australian lungfish (Neoceratodus forsteri), thought to be the closest living relative to the first terrestrial vertebrates. The DNA of five visual pigment genes in the retinas of lungfish reveals that these have more in common with four-legged vertebrates (tetrapods) than with fish retinas.

Lungfish were previously thought to have poor eyesight due to their small eyes, low spatial resolving power, sluggish behaviour in captivity and ability to detect prey using electroreception. N.forsteri inhabits a brightly lit, shallow freshwater habitat similar to the environment from which terrestrial evolution probably occurred. This prompted the team to investigate the complement of visual proteins expressed in N. forsteri, to trace photoreception's evolution in ancestral tetrapods.

"The genus Neoceratodus, of which N. forsteri is the sole survivor, is found in the fossil record from the Lower Cretaceous period 135 million years ago and therefore N. forsteri lays claim to being the oldest surviving vertebrate genus," says Bailes. "The visual system of N. forsteri may represent an evolutionary design most closely reflecting that present just prior to the emergence of land vertebrates in the Devonian period."

A Cool Sound Outta Hell

My friend Jackson Phibes' band The Forbidden Dimension have just released their new LP on Saved By Vinyl. Go pick a copy today! Watch for gigs by the band in and around Calgary.

Our friends over that Atomic Surgery have even dusted off their blog to celebrate the new release!

Born This Day: Francis Maitland Balfour

Nov. 10, 1851 - July 19, 1882

Balfour was a founder of modern embryology. Influenced by the work of Michael Foster, with whom he wrote Elements of Embryology (1883), Balfour showed the evolutionary connection between vertebrates and certain invertebrates (similar to research being done by Aleksandr Kovalevski). Balfour proposed the term Chordata for all animals possessing a notochord at some stage in their development. While convalescing from typhoid fever in Switzerland, he died at the young age of 30 from a fall while attempting an ascent of the unconquered Aiguille Blanche of Mont Blanc.
From Today In Science History

Died This Day: Gideon Algernon 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.

Pictures

A round up of photos I've been meaning to post for a while:

Eric Snively probably has the coolest dino t-shirt ever - drawn by one of his former students. I think it should be the Palaeoblog's unofficial mascot!


Long time friend and Palaeoblog supporter, Lisa Zap (& kids, below) play with a snake.



Lisa also sent me these photos of sand sculptures from last summer's Capital Ex in Edmonton.











I could not make it out to Calgary for the recent Dinosaur Research Institute's fund raiser, but my friend Chad Kerychuk did and he took the following photos:


Eva, Chad and Phil


Martha Dunsmore, long-time palaeo supporter and badlands explorer.


Ace sculptor Brian Cooley donated this great theropod head.

Items in the auction. That's a Mike Skrepnick original below left.

Dinos From Beyond The Grave

Kipling West posted this image from the Calgary Zoo on the 7 Deadly Sinners site. Presumably taken on Halloween....

Collecting an Oviraptorid Nest in the Gobi

As part of the Nomadic Expeditions trip to the Gobi last summer we were fortunate enough to find and collect an oviraptorid skeleton on top of a nest of eggs.


The nest was found by Ph.D. student, Frederico Fanti (right, with Phil Currie), who was examining sedimetary structures in the Nemegt basin. The nest and skeleton were exposed in cross-section coming out of a cliff about 2 meters above the ground. Erosion had destroyed the tail and one margin of the nest but the rest was complete, including the skull. Frederico has his hand on the exposed portion of the nest.


Work commences on the specimen. You can see the stacked dunes sequences on the cliff face.

Much of the excavation was done in the rain. Many thanks to Nick Longrich who had the foresight to bring a large tarp (for protection from the sun he thought!)


Clive Coy, Frederico, and Phil work on the specimen.


Frederico expresses his opinion on hardness of the rock that had to be carved away.


Tom Owen, Eva Koppelhus and Miriam Reichel pedestal the nest and skeleton.


The block was rolled in a van and the field jacket finished as we pulled out of camp at the end of the trip - everything always happens at the last minute!


Victoria Arbour, Federico, and Miriam celebrate the successful collection of the specimen.

When Animals Evolve On Islands, Size Doesn't Matter

The island rule: made to be broken?. 2007. S. Meiri, et al. Proceedings of the Royal Society B, early on-line publication

From the press release:

A new study refutes the ‘island rule’ which says that in island environments small mammals such as rodents tend to evolve to be larger, and large mammals such as elephants tend to evolve to be smaller, with the original size of the species being the key determining factor in these changes.

The new research findings suggest that the tendency to either evolve larger or smaller on islands varies from one group of species to another, irrespective of original size. The research team suspect instead that a number of external factors, including the physical environment of the particular island, the availability of prey, the presence of predators and the presence of competing species all play a role in determining the size evolution of island mammals.

“Our analyses showed that the relationship between mammal size and evolutionary size change on islands is not that straightforward. Crucially, when we examined size change in light of the evolutionary relationship between different species, there was no connection between an evolution towards large size and greater degree of dwarfism on islands, or between evolution towards small size and island gigantism.”

The research team concluded that although there does appear to be a weak correlation between the size of a mammal and how its size then evolves in an island habitat, this reflects some groups’ specific tendencies towards gigantism or dwarfism, and not the general course of evolution.

Velociraptor Breathed Like A Bird

Avian-like breathing mechanics in maniraptoran dinosaurs.2007. J.R. Codd, et al. Proceedings of the Royal Society B: Biological Sciences, published on-line Nov. 6.

Abstract: In 1868 Thomas Huxley first proposed that dinosaurs were the direct ancestors of birds and subsequent analyses have identified a suite of ‘avian’ characteristics in theropod dinosaurs. Ossified uncinate processes are found in most species of extant birds and also occur in extinct non-avian maniraptoran dinosaurs. Their presence in these dinosaurs represents another morphological character linking them to Aves, and further supports the presence of an avian-like air-sac respiratory system in theropod dinosaurs, prior to the evolution of flight.

Here we report a phylogenetic analysis of the presence of uncinate processes in Aves and non-avian maniraptoran dinosaurs indicating that these were homologous structures. Furthermore, recent work on Canada geese has demonstrated that uncinate processes are integral to the mechanics of avian ventilation, facilitating both inspiration and expiration.

In extant birds, uncinate processes function to increase the mechanical advantage for movements of the ribs and sternum during respiration. Our study presents a mechanism whereby uncinate processes, in conjunction with lateral and ventral movements of the sternum and gastral basket, affected avian-like breathing mechanics in extinct non-avian maniraptoran dinosaurs.

Born This Day: Aleksandr Kovalevsky

Nov. 7,1840 – Nov. 9,1901

image

From Today In Science History:

Kovalevsky was the Russian founder of comparative embryology and experimental histology. He established that there was a common pattern in the embryological development of all multicellular animals. He studied the tiny lancelet, a fish-shaped sea animal, then wrote Development of Amphioxus lanceolatus (1865).

In 1866, he demonstrated the similarity between Amphioxus and the larval stages of tunicates and established the chordate status of the tunicates. In 1867, Kovalevsky extended the germ layer concept of Christian Heinrich Pander and Karl Ernst von Baer to include the invertebrates, establishing an important embryologic unity in the animal kingdom.

Sing along!

The Amphioxus Song:

A fish-like thing appeared among the annelids one day.
It hadn't any parapods nor setae to display.
It hadn't any eyes nor jaws, nor ventral nervous cord,
But it had a lot of gill slits and it had a notochord.

Chorus:
It's a long way from Amphioxus. It's a long way to us.
It's a long way from Amphioxus to the meanest human cuss.
Well, it's goodbye to fins and gill slits, and it's welcome lungs and hair!
It's a long, long way from Amphioxus, but we all came from there.

The rest of the lyrics and the story behind the song Here

Died This Day: Alfred Russel Wallace

Jan. 8, 1823 – Nov. 7, 1913

From Today In Science History:

Wallace was a British naturalist and biogeographer. He was the first westerner to describe some of the most interesting natural habitats in the tropics. He is best known for devising a theory of the origin of species through natural selection made independently of Darwin.

Between 1854 and 1862, Wallace assembled evidence of natural selection in the Malay Archipelago, sending his conclusions to Darwin in England. Their findings were jointly presented to the Linnaean Society in 1858. Wallace found that Australian species were more primitive, in evolutionary terms, than those of Asia, and that this reflected the stage at which the two continents had become separated. He proposed an imaginary line (now known as Wallace's line) dividing the fauna of the two regions.

The Alfred Russel Wallace page HERE. More HERE.

Hans Larsson: Building a Better T. rex

Hans Larsson and his evo/devo work trying to turn chickens in tyrannosaurs had a nice write up in The Globe & Mail last Saturday.

Check out the photo gallery HERE.

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.

Mesozoic Birds Looked to the Skies But Lived On The Ground

Foraging modes of Mesozoic birds and non-avian theropods. 2007. C.L. Glen, and M. B. Bennett. Current Biology Vol 17, R911-R912, 06 November 2007.

Earliest birds acted more like turkeys than common cuckoos

From the press release:

By comparing the claw curvatures of ancient and modern birds, the researchers provide new evidence that the evolutionary ancestors of birds primarily made their livings on the ground rather than in trees.

“The claws of Mesozoic birds and their immediate ancestors, the non-avian theropods, are relatively ‘straight’—most like [those] of birds that are now either specialized for walking on the ground or have a preference for it, rather than the highly curved claws of birds that spend a lot of time in trees,” said Christopher Glen.

“In summary,” they concluded, “since claw angle is independent of body size and the evolutionary relationships among species, it is a reliable indicator of the predominant behavior reliant upon hind-limb locomotion, and can make an important contribution to reconstructing the ‘ecomorphology’ of fossil species—how they lived and used their environments. Our findings suggest early birds foraged predominantly on the ground, rather than supporting previous suggestions of arboreal claw adaptations, which appear to have evolved later in the lineage.”

Weird Scenes Inside the Gold Mine

Tony Fiorillo & the circus

Alison Abbott in Nature reports on the the recenting 'doings' up in Alaska when Tom Rich from Australia and a film crew decided to set up a mining operation next to Tony Fiorillo's on-going research excavation. Really, what were they thinking? We've all had weird experiences with film crews but this one has to go down in the books.

I could download a PDF of the article HERE. Maybe you can to.

Flying Lemurs Perch With Primates

Molecular and Genomic Data Identify the Closest Living Relative of Primates. 2007. J. Janeka et al. Science 318: 792-794.

The study indicates that colugos (flying lemurs), rather than tree shrews, are genetically more closely related to primates. Further sequencing of the colugo genome is warranted, in order to develop a better understanding of the evolutionary changes leading to primates, as well as to more accurately reconstruct the ancestral primate genome.

According to Murphy, the origins of primates and primates found in the fossil record have been a topic of intense debate as there has been an increased focus on identifying adaptive evolutionary changes with primates. By decoding the past through changes in genomics, a clearer picture of the evolution of primates emerges that will provide a broader context for future research, he said.

“In addition to identifying colugos as the closest living relative to primates, we were able to make some very important discoveries about the tree shrews,” said Murphy. “The phylogenetic uniqueness we documented in Ptilocercus, coupled with its restriction to a lowland forest habitat and limited global range, have certainly identified it as an important conservation effort in a global sense.

Born This Day: Sir Gavin de Beer

Illo © Nick Longrich

Nov. 1 1899 – June 21, 1972

From Today In Science History:

de Beer was an English zoologist and morphologist who contributed to experimental embryology, anatomy, and evolution. He refuted the germ-layer theory and developed the concept of paedomorphism - the retention of juvenile characteristics of ancestors in mature adults).

From examination of the fossil Archaeopteryx, De Beer proposed mosaic evolution with piecemeal evolutionary changes to explain the combination of bird and reptile features.

Born This Day: Father of Continental Drift

Nov. 1, 1880 – Nov, 1930

From Today In Science History:

Visit The Paleomap Project

Alfred Lothar Wegener was a German meteorologist and geophysicist who first gave a well-developed hypothesis of continental drift. He suggested (1912) that about 250 million yrs ago all the present-day continents came from a single primitive land mass, the supercontinent Pangaea, which eventually broke up and gradually drifted apart. (A similar idea was proposed earlier by F.B. Taylor in 1910.) Others saw the fit of coastlines of South America and Africa, but Wegener added more geologic and paleontologic evidence that these two continents were once joined.

Deccan Traps Killed T. rex

Devil Dinosaur © Marvel Comics

From the press release:

A series of monumental volcanic eruptions in India may have killed the dinosaurs 65 million years ago, not a meteor impact in the Gulf of Mexico. The eruptions, which created the gigantic Deccan Traps lava beds of India, are now the prime suspect in the most famous and persistent paleontological murder mystery, say scientists who have conducted a slew of new investigations honing down eruption timing.

"It's the first time we can directly link the main phase of the Deccan Traps to the mass extinction," said Princeton University paleontologist Gerta Keller. The main phase of the Deccan eruptions spewed 80 percent of the lava which spread out for hundreds of miles. It is calculated to have released ten times more climate altering gases into the atmosphere than the nearly concurrent Chicxulub meteor impact, according to volcanologist Vincent Courtillot from the Physique du Globe de Paris.

Keller's crucial link between the eruption and the mass extinction comes in the form of microscopic marine fossils that are known to have evolved immediately after the mysterious mass extinction event. The same telltale fossilized planktonic foraminifera were found at Rajahmundry near the Bay of Bengal, about 1000 kilometers from the center of the Deccan Traps near Mumbai.

The microfossils demonstrate directly that the biggest phase of the eruption ended right when the aftermath of the mass extinction event began. That sort of clear-cut timing has been a lot tougher to pin down with Chicxulub-related sediments, which predate the mass extinction.

"Our K-T age control combined with these results strongly points to Deccan volcanism as the likely leading contender in the K-T mass extinction."

From a presentation at the recent GSA Annual Meeting in Denver.

500 Million Year Old Jellyfish

Exceptionally Preserved Jellyfishes from the Middle Cambrian. 2007. Cartwright. P. et al. PLoS ONE 2(10): e1121.


Cambrian fossil jellyfish shows similarity to the modern jellyfish, Cunina (right). Fossil photo by B. Lieberman. Cunina photo by K. Raskoff, copyright

From the press release:

Researchers describe four types of 500 million years old cnidarian fossils from Utah that preserve traits that allow them to be related to modern orders and families of jellyfish. The specimens are about 200 million years older than the oldest previously discovered jellyfish fossils.

The jellyfish left behind a film in fine sediment that resembles a picture of the animal, including a distinct bell-shape, tentacles, muscle scars and possibly even the gonads.

With the discovery of the four different types of jellyfish in the Cambrian there is now enough detail to assert that the types can be related to the modern orders and families of jellyfish. The specimens show the same complexity. That means that either the complexity of modern jellyfish developed rapidly roughly 500 million years ago, or that the group is even older and existed long before then.

Casting A Deep Shadow

From National Geographic news:

David Fillmore, a Kutztown State University undergraduate student, digging through a collection of fossils in a Pennsylvania museum recently found beautifully preserved full-body impressions of 30 cm salamander-like creatures that lived 330 million years ago.

The imprints reveal that the animal had webbed feet and that its skin was smooth, not scaly or armor-plated, as seen in an artist's depiction. Also, the fact that two of the salamanders are aligned head-to-toe might indicate courtship behavior similar to that engaged in by modern salamanders.

The work was presented by Spencer Lucas at the recent Geological Society of America meeting in Denver, Colorado.