Stories tagged Diversity of Organisms

Aug
18
2014

Hallucigenia sparsa fossil: from the Burgess Shale
Hallucigenia sparsa fossil: from the Burgess ShaleCourtesy M. R. Smith / Smithsonian Institute
One of the strangest and more mysterious critters that scurried across the Middle Cambrian seafloor has baffled paleontologist since it was first identified in the 1970s. Was it a worm? Which side was up? Did it have legs or spikes or both? Was its head actually its tail? Did it have any extant descendents or was it an evolutionary dead-end? The worm-like creature was so baffling and so bizarre, it was given the very apropos name of Hallucigenia.

The tubular, spiked-worm possessed seven or eight pairs of legs and ranged in length from 2/5th of an inch to one and 1/4 inches and looks like something out of a bad dream. Early interpretations of their fossils were all over the map. The stiff spikes on it back were first thought to be its legs, and its legs misidentified as tentacles. What was thought to be its tail ended up being its head.

Using modern imaging technology, researchers from the University of Cambridge have been closely studying fossils from the famous Burgess Shale quarry located high in the Canadian Rockies, and are uncovering Hallucigenia's secrets. By studying the claws at the end of its legs they have been able to link it to modern velvet worms (onychophorans). Scientists have long suspected the two were somehow related but until now have failed to find anything significant to prove it. By studying Hallucigenia's claws they've determined that they're constructed of nested cuticle layers, very similar to how the jaws of velvet worms are organized. The similarity is no surprise since jaws are known to have evolved from a modified set of front legs.

But besides giving Hallucigenia a place in the lineage of life on Earth, the Cambridge team during the course of their study also discovered something else: that arthropods - which include crustaceans, spiders, insects and trilobites - aren't in fact as closely related to velvet worms as previously thought.

“Most gene-based studies suggest that arthropods and velvet worms are closely related to each other," said co-author Dr Javier Ortega-Hernandez. "However, our results indicate that arthropods are actually closer to water bears, or tardigrades, a group of hardy microscopic animals best known for being able to survive the vacuum of space and sub-zero temperatures – leaving velvet worms as distant cousins.”

SOURCE and LINKS

University of Cambridge story
Previous Buzz Post on Hallucigenia
The Cambrian Explosion
More about Tartigrade

May
19
2014

Early dinosaur hyperbole: New York newspaper from December, 1898
Early dinosaur hyperbole: New York newspaper from December, 1898Courtesy Public domain
The Internet has been all a-buzz lately about the largest dinosaur - EVER - being discovered in Argentina. The beast is massive - equal to 14 elephants and as long as two tractor trailers! The story's accompanying photo (several, in fact) often shows an adult man laid out next to a gigantic titanosaur femur. Pretty impressive, at least at first. But the problem I had was finding out some idea of how long the bone was or how tall the man was. It's all relative, of course. It reminds of one of my favorite W. C. Fields scenes is in the movie YOU CAN'T CHEAT AN HONEST MAN where he plays a carnival barker at a sideshow touting the World's Largest Midget and the World's Smallest Giant, and featuring two guys of average height.

Giant dinosaur bone = giant guy: Evidently, Bill Reed was a big, big man
Giant dinosaur bone = giant guy: Evidently, Bill Reed was a big, big manCourtesy Public domain
This kind of hyperbole has been around ever since dinosaurs were first discovered. If the bone pictured in the 1898 New York Advertiser article is as large as the caption claims, then the man standing next to it, William Harlow Reed, is eight feet tall as well(!) - an equally if not more impressive story that the newspaper obviously overlooked.

It should be noted that the sensational discovery was the catalyst for steel magnate Andrew Carnegie to spend lots of money to get himself his own dinosaur (Diplodocus carnegiei) in 1899. It wasn't quite as large as the one that inspired his quest but casts of Carnegie's dinosaur were given to various foreign heads of states, helping spread dinosaur fever to the world.

SOURCES and LINKS
BBC story
Geo Scienze blog (in Spanish)
CNN story
Everything Dinosaur blog
Sauropod Vertebrate Picture of the Week

May
12
2014

Pterodactylus ancestor discovered
Pterodactylus ancestor discoveredCourtesy Mark Ryan
Over in China, out of one of the richest hunting grounds for new and unusual dinosaur-era fossils, the earliest known member in the family of flying reptiles known as pterosaurs has been described in a paper published in Current Biology.

Named Kryptodrakon progenitor, the ancestral pterodactyloid was discovered in mudstones in the highly fossiliferous Shishugou Formation of northwest China by a team of international paleontologists.

The flying reptile's name essentially means "first-born hidden serpent", the genus name Kryptodrakon referring to the popular martial arts film, "Crouching Tiger, Hidden Dragon" which was filmed near the location where the fossil was discovered in the Chinese autonomous region known as Xinjiang.

Sporting a wingspan of some 4.5 feet, Kryptodrakon lived in a floodplain environment during the Middle-Upper Jurassic period, about 163 million years ago. Descendents of the newly-discovered pterodactyloid would evolve into much larger flying reptiles such as the giant, Cessna-sized Quetzacoatlus found in Late Cretaceous sediments in Texas. Pterosaurs were not dinosaurs but share a common ancestor with them.

The research increases our knowledge of pterosaur development and was led by Brian Andres from the University of South Florida (USF), James Clark of George Washington Columbia College of Arts and Sciences, and Xu Xing of the Chinese Academy of Sciences.

SOURCES and LINKS
Science Daily story
Pterosaur page
Paper in Current Biology

Apr
13
2014

Tiktaalik roseae: Field Museum of Natural History
Tiktaalik roseae: Field Museum of Natural HistoryCourtesy Eduard Solà via Wikipedia
If you missed last week's PBS broadcast of Your Inner Fish, the documentary based on paleontologist-anatomist Neil Shubin's book by the same name, you have another chance to catch up on the first of three segments on the web. It's an excellent opening segment of the 3-part series, but is only available (for free!) right here through April 23, 2014.

The series deals with Shubin's search for the connections we all have with our fishy and reptilian ancestors. His discovery of the remarkable transitional fossil named Tiktaalik roseae on Ellesmere Island in the Canadian Arctic has added great evidence of our ties with our distant piscean relatives. The flat-headed, 375 million year-old Tiktaalik possessed the exact features - such as both lungs and gills, a wrist and neck - that you'd hope to find in a transitional form between swimming fish and land-walking tetrapods.

The next episode, titled Your Inner Reptile airs Wednesday, April 16th on your local PBS station. It's on here in the Twin Cities at 9pm but check your local listing for times in your area.

In the meantime, watch the first episode, and read about some of the reaction to Shubin's find here, here, and here.

LINKS
University of Chicago Tiktaalik roseae page

Mar
05
2014

Virus: Giant viruses are genetically more complex and about 25 percent larger.
Virus: Giant viruses are genetically more complex and about 25 percent larger.Courtesy jiparis
A husband-and-wife-led research team has announced finding an ancient virus laying dormant in Siberian permafrost for more than 30,000 years!

Jean-Michel Claverie and Chantal Abergel of Aix-Marseille University in France and their colleagues cut up pieces of permafrost samples - supplied by scientists from the Russian Academy of Science - and added them to petri dishes of amoebae only to see the one-celled animals ripped apart by unknown viruses. They isolated the attacking, larger-than-usual virus and named it Pithovirus sibericum, because of its resemblance to an earthenware jar. The permafrost samples had been collected from a frozen riverbank in Siberia in 2000.

The discovery brings the total number of known "giant viruses" to three. The extra-large viruses are about 25 percent larger than normal, genetically more complex, and composed of hardier stock.

"Among known viruses, the giant viruses tend to be very tough, almost impossible to break open," said Claverie and Abergel. "Special environments such as deep ocean sediments and permafrost are very good preservers of microbes because they are cold, anoxic and in the dark."

Two other giant viruses Mimivirus and Pandoravirus were also discovered by Claverle and Abergel in the last decade. The latter, in my opinion, is a disturbingly great name for this type of thing. But so far only the pithovirus has been observed in the laboratory infecting contemporary life forms. Luckily, none of them pose a threat to humans, but that's not to say future giant viruses thawed out of frozen environments or released by retreating ice caps won't be.

"I don't see why they wouldn't be able to survive under the same conditions," said Claverie.

Results of the research appear in the Proceedings of the National Academy of Sciences.

SOURCES and LINKS
National Geographic story
Sydney Morning Herald
More about giant viruses

Mar
03
2014

Numbered days?: Zebra mussels totally cover a piece of underwater equipment from Lake Michigan.
Numbered days?: Zebra mussels totally cover a piece of underwater equipment from Lake Michigan.Courtesy M. McCormick
For more than 20 years, zebra mussels have gone unchecked in midwest waters. Introduced to North America as stow-away passengers on the bottoms of Great Lakes shipping vessels that came from Europe, the invasive species have exploded to fresh waters in 34 states at an alarming rate.

But their days may be numbered. A New York-based researcher has discovered a bacterium that can kill zebra mussels (and also the related invasive species quagga mussels) without disrupting the rest of the food web.

After rounds of lab testing, the Environmental Protection Agency has okayed the commercial production of Pseudomonas fluorescens strain CL145A, which can then be applied to waters and kill the menacing mussels. In lab tests, the bacterium killed over 90 percent of the the invasive mussels in came in contact with.

Along with pushing out other species in the waters, the invasive mussels have also become a nuisance by clogging up intake pipes at water plants and attaching themselves to docks, piers and other submerged water equipment. Plans are still being developed on how to apply this new bacterium to the waters. All wise zebra mussels might want to start packing their bages and heading back to Europe before they find out what this new bacterium has in store for them!

Dec
28
2013

Restoration of Haplocanthosaurus: a Late Jurassic sauropod whose remains are found in Colorado, Utah, and Wyoming.
Restoration of Haplocanthosaurus: a Late Jurassic sauropod whose remains are found in Colorado, Utah, and Wyoming.Courtesy FunkMonk via Wikimedia Commons
The partial remains of a somewhat rare sauropod dinosaur have been discovered in Old Snowmass, near Aspen, Colorado. Paleontologist John Foster of the Museum of Western Colorado in Grand Junction said that fossils of a Haplocanthosaurus were found by college student Mike Gordon in 2005 on land owned by his mom and stepfather. If you remember, Snowmass was the site near Aspen where a large collection of mammoths, mastodons, and other Ice Age mammals were uncovered back in 2010. This latest discovery is about six miles from the other site but in a much, much older rock layer. Foster said the Lower Morrison Formation, from where Haplocanthosaurus remains were collected dates back to the Late Jurassic, about 155-152 million years ago.

It's a very exciting find because few specimens of Haplocanthosaurus exist. The first were also found in Colorado, in Garden Park near Canon City, by Carnegie Museum of Natural History paleontologists William H. Utterback and John Bell Hatcher in 1901. The type specimens (H. priscus and H. utterbacki) were described by Hatcher in 1903. The fossils were prepared under the direction of chief preparator, Arthur S. Coggeshall.

Mounted skeleton of Haplocanthosaurus delfsi: Cleveland Museum of Natural History
Mounted skeleton of Haplocanthosaurus delfsi: Cleveland Museum of Natural HistoryCourtesy ScottRobertAnselmo via Wikimedia Commons
Compared to its larger and heavier long-necked, small-headed cousins such as Apatosaurus and Diplodocus, the Haplocanthosaurus was a relatively small-sized sauropod dinosaur with a length of 35 to 40 feet and weighing maybe 14 tons. While most sauropods have hollow spaces in their backbones, a distinguishing characteristic of Haplocanthosaurus is the solidness of its vertebrae which Foster confirmed by doing a scan of the fossil bones at a local hospital in Grand Junction.

Haplocanthosaurus hindlimb: Science Museum of Minnesota
Haplocanthosaurus hindlimb: Science Museum of MinnesotaCourtesy Mark Ryan
The only mounted specimen of Haplocanthosaurus is the referred species (H. delphsi) on exhibit at the Cleveland Museum of Natural History in Ohio. No skull of the sauropod has ever been found so the head is just a fabricated guess. Other post-cranial remains exist, including some here at the Science Museum of Minnesota that were collected in Wyoming, but in general fossils of the dinosaur are rare. Material from only 10 individuals are known.

So far the Old Snowmass site has provided some vertebrae, ribs and a pelvis. but the landowners have been very accommodating in allowing the museum access to the dig site, and Foster hopes to find more Haplocanthosaurus bones - maybe even some skull material - in the coming summer season.

SOURCES and LINKS
Aspen Times story
More Haplocanthosaurus info
Osteology of Haplocanthosaurus by John Bell Hatcher
Jurrassic West: The Dinosaurs of the Morrison Formation and Their World by John Foster

Dec
09
2013

Charlie Darwin: The schoolbook victory in Texas obviously makes him feel like Charlie Sheen.
Charlie Darwin: The schoolbook victory in Texas obviously makes him feel like Charlie Sheen.Courtesy National Portrait Gallery
Last month, on November 22nd, while many people in the country were observing the 50th anniversary of president John F. Kennedy's assassination by shots fired from the Texas School Book Depository, there was another significant event happening that day involving Texas schoolbooks. That same Friday, despite objections and obstructionist tactics by creationists, the Texas Board of Education approved several public school science textbooks that included full coverage of evolution and climate change. The vote came late in the day and although the creationist faction did manage to make the adoption of two biology books contingent on a committee ruling regarding some alleged "flaws" in the text, the Texas Freedom Network (TFN), a watchdog group instrumental in countering the irrational creationist attacks, expects the passage to stand.

“It’s hard to overstate the importance of today’s vote, which is a huge win for science education and public school students in Texas,” said Kathy Miller, TFN's president. “Four years ago this board passed controversial curriculum standards some members hoped would force textbooks to water down instruction on evolution and climate change. But that strategy has failed because publishers refused to lie to students and parents demanded that their children get a 21st-century education based on established, mainstream science.”

SOURCES
Dallas Morning News story
Evolution is True article

Oct
23
2013

With the announcement of the Ultimate Dinosaurs: Giants of Gondwana exhibit comming to the Science Museum of Minnesota, I was thinking back to all the questions I have had regarding dinosaurs. Tyrannosaurus rex: the Tyrant Lizard King on display at the Royal Tyrrell Museum in Drumheller, Alberta.
Tyrannosaurus rex: the Tyrant Lizard King on display at the Royal Tyrrell Museum in Drumheller, Alberta.Courtesy Mark Ryan

Questions like: "Who gets to name Dinosaurs?" "What is this dinosaur named after?" and "What does this name mean?". I thought that I'd take some time here to answer these questions.

Oct
16
2013

Turkey vulture (Cathartes aura): an ugly yet somewhat majestic raptor species often seen soaring around Hawk Ridge in Duluth, Minnesota during the annual fall migration.
Turkey vulture (Cathartes aura): an ugly yet somewhat majestic raptor species often seen soaring around Hawk Ridge in Duluth, Minnesota during the annual fall migration.Courtesy Mark Ryan
Birds seem to be a big part of my recent experience, so I thought I'd put together a little post of events featuring our fine, feathered friends.

Here at the Science Museum of Minnesota, an antique model of Archaeopteryx originally created by modelmaker Gustaf Sundstrom in 1934 is on display once again as Object of the Month for October. Archaeopteryx model by Gustaf Sundstrom
Archaeopteryx model by Gustaf SundstromCourtesy Mark Ryan
Archaeopteryx has long been considered the earliest bird - it lived around 150 million years ago during the Late Jurassic - sharing the world with giant sauropods and vicious therapods such as Apatosaurus and Allosaurus, respectively. Even though Archaeopteryx has been recently re-categorized from being a "dinosaur-like bird" to being a "bird-like dinosaur" (I'm not sure what the difference is but I suspect it has do do with percentages) - anyway, it still ranks as one of the great transitional fossils. You can see the Object of the Month display in the Collections Gallery on the 4th floor of the Science Museum of Minnesota all this month.

Another bird-related story deals with naturalist and artist John James Audubon and his artistic masterpiece Birds of America, both which I've covered before here.

Audubon's Whooping Crane: plate no. 226 from the artist's masterpiece Birds of America.
Audubon's Whooping Crane: plate no. 226 from the artist's masterpiece Birds of America.Courtesy Mark Ryan
Back in the early 19th century Audubon, tramped around the American frontier seeking just about every kind of bird he could find, shoot, and paint for his masterpiece natural history tome, Birds of America. The original edition featured 435 exquisite plates of birds drawn in natural size, were etched in copperplates (along with some engraving and aquatint), then printed in black and white and printed on large double-elephant folio-sized (30 x 40) handmade paper. Each of the large black and white prints were hand-painted in watercolors by a team of skilled colorists and bound into two volumes. Long considered one of the greatest collections of natural history illustration, only some 200 sets were completed in the mid-19th century. Of those only about 100 remain in existence. The rest were either destroyed or disassembled and sold off as individual prints. Because they were hand-colored, these large first editions are considered "originals" and are quite valuable. Smaller, more inexpensive prints and editions were later created and sold.

Audubon exhibit: Preview Night at the Bell Museum
Audubon exhibit: Preview Night at the Bell MuseumCourtesy Mark Ryan
Lucky for us one of the original Double Elephant Folio sets is held by the Bell Museum of Natural History in Minneapolis. Even luckier for us, the Bell has just opened a brand new exhibit, called Audubon and the Art of Birds, which is centered around some of these beautiful originals of Audubon's wonderful illustrations. I attended the preview a couple weeks back and let me tell you, it is a chance in a lifetime to see these rare and beautiful natural history illustration masterpieces. The exhibition opened on October 5th and runs in two sections. Right now, 33 of Audubon's mammoth prints grace the walls of the exhibit (along with illustrations by other bird artists) then other restored mammoth prints of Audubon illustrations will be rotated in during a two week shutdown in January, and the exhibit's second half reopens on February 1st. Find more information about the exhibition here.

On the lookout for birds: Visitors to Hawk Ridge Bird Observatory scan the skies for migrating raptors above Duluth, Minnesota.
On the lookout for birds: Visitors to Hawk Ridge Bird Observatory scan the skies for migrating raptors above Duluth, Minnesota.Courtesy Mark Ryan
Last week, my wife and I took a day-trip to Duluth and stopped at Hawk Ridge Bird Observatory, located on Skyline Parkway overlooking the east end of the city. The site is a favorite autumn destination for bird-watchers of all kinds. Snared and tagged raptor: Hawk Ridge volunteer Jessica displays the wing of a sharp-shinned hawk.
Snared and tagged raptor: Hawk Ridge volunteer Jessica displays the wing of a sharp-shinned hawk.Courtesy Mark Ryan
Official bird-counters were still there tabulating hawks, eagles and other raptors migrating south for the winter. The count will continue through October. Set and release: a lucky Hawk Ridge visitor launches a banded sharp-shinned hawk back into the wild.
Set and release: a lucky Hawk Ridge visitor launches a banded sharp-shinned hawk back into the wild.Courtesy Mark Ryan
The birds don't like crossing the wide expanse of Lake Superior on their way south, so they funnel into Duluth to cross there. We only saw a couple birds in the air while we were there (some 680 had been counted earlier in the day), but a couple of hawks snared just down the road were brought up to the ridge overlook for banding and release. Volunteers tagged and recorded the hawks (a goshawk - Accipiter gentilis - and a sharp-shinned hawk - Accipiter striatus), then enlisted the help of a couple of lucky onlookers to release them back into the wild. It was a beautiful afternoon on the Ridge.

LINKS
Object of the Month
Audubon and the Art of Birds
Hawk Ridge Bird Observatory
View Birds of America prints via the University of Pittsburgh