Eliabeth Vrba -- Great Exaptations!

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Elisabeth Vrba at Middle Awash field study area in 1990. Photo (c) and courtesy of Tim White.

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“I’m interested in pushing out the frontiers of science, not sailing my boat through tranquil seas.”—Elisabeth Vrba

Elisabeth Vrba is a world-renowned palaeontologist and one of the most brilliant minds among living scientists. Her contributions to mammalian palaeontology and to the theory of macroevolutionary processes are milestones that have enriched our knowledge of the field since the early 1970s.

Vrba (born 17 May 1942) earned her Ph.D. in Zoology and Palaeontology at theUniversity of Cape Town in 1974. As a young trowelblazer she began working for the Transvaal Museum and coordinated excavations at the famous australopithecine site of Sterkfontein. In the late 80s, she moved to the US with her husband and daughter, where she joined the faculty of Yale University. She is currently a professor in the Department of Geology and Geophysics and curator of Vertebrate Paleontology at Yale’s Peabody Museum.

We can suppose that almost two decades (from the late ‘60s till the late ‘80s) of field work in South Africa and intensive study of museum collections have inspired and nurtured ESV’s brilliant ideas. The development of the Turnover Pulse Hypothesis is undoubtedly one of her most significant contributions in macroevolutionary theory (together with the coining of the word exaptation with S. J. Gould).

by Roberto Rozzi (@rozzi_roberto)

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Sabertooth diaries 1: excavating old sketches by Mauricio Antón

“As the publication of my book  ”Sabertooth” comes closer, I am trying to put some order in the mass of material I have been working with during the last few years. It is interesting to leaf through those fat folders full of sketches, some of them dating from MANY years ago: it refreshes my memory about some of the main subjects I have dealt with in the book, and in fact, it motivates me to tackle some of these subjects again, in anticipation for the next book (title to be disclosed at some point in the future…).

Here are some of those “paleo-sketches” (in the whole sense of the word!). They date from more than 15 years ago (Gosh!) and were  my early attempts to put together observations about key aspects of big cat anatomy, especially related to hunting…(these drawings do not appear in the book or anywhere else  in this form, so this is a sort of exclusive…)

In the years after I did these sketches I have found many fascinating things about these aspects of felid anatomy, which I have tried to reflect in the new book. These days I am preparing a short video about some of these things, I expect to be posting it soon!”

  • First image: “compares the “primitive” skeletal porportions of the early cat Pseudaelurus (left) with those of the very different cheetah (Acinonyx) and sabertooth (Smilodon). Obviously, the skeletons and cats are not shown to scale”
  • Second image: “shows aspects of the anatomy of the cheetah, with special attention to the lumbar vertebrae.  For the fun of it, I also included a body size comparison betwen the modern cheetah and the extinct species Acinonyx pardinensis.  Back then I was already puzzled by the possible meaning of the changes in body proportions during the evolution of sabertooths, and in particular in the shortening of the lumbar vertebra in many species”
  • Third image: “shows the sequence of events during a hypothetical hunt by the sabertooth Smilodon: the chase (top); the wrestling struggle (middle); and the killing bite (bottom)”
  • Fourth image: “shows the crucial point when the cat attempts to pull a large prey down to the ground, and it highlights some of the muscles relevant for that action”

(Image and text source: Chasing Sabretooths; via @Laelaps on Twitter)

Stunningly Intact Dinosaur Fossil

The almost perfectly complete fossil of a young theropod dinosaur – including some preserved hair and skin* (see update below) – was unveiled yesterday by scientists from the Bavarian paleontological and geological collections (BSPG) in Munich, Germany. BSPG conservator Oliver Rauhut described it as the best preserved dinosaur skeleton to have ever been found in Europe.

Darren Naish, palaeontologist at the University of Southampton, says the fossil is “incredible”. Rauhut says that fossils of theropod dinosaurs, which include the genus Tyrannosaurus, are rare and usually fragmented. “The best-preserved Tyrannosaurus we have are about 80 percent preserved, and that is already terrific,” he says. The new fossil is around 98% intact.

The dinosaur died around 135 million years ago at a site near the present town of Kelheim in the southern German state of Bavaria. Rauhut and his team of palaeontologists think it was no more than a year old

Naish hopes that the bone preservation in the fossil is as outstanding as it looks in the publically-released photo, because this might help scientists piece together the phylogeny of theropod species. No data is available on the fossil yet, so Naish can only speculate, but he says the dinosaur seems to have proportionally shorter legs, and a longer tail, than have been seen in other similar theropods. Particularly tantalising is the question of whether these differences are attributable to the dinosaur being a juvenile, or if it might be an example of a new species.

Read more.

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Today is so exciting for a ton of fellow palaeontologists, students, researchers, and myself… Dreadnoughtus has finally been published!

The video above gives you guys a bit of history to where this titanosaur was discovered back in 2005. Almost ten years later and it’s finally gone public! With a name like Dreadnoughtus, it’s hard not to want to run around saying its awesome name.

These fossils spent a lot of time being excavated out of the matrix they were found in; around 4 years with multiple labs working tirelessly to clean and repair them. We had to get it done at least in some sort of quick time, right? With such a huge specimen, a lot of man power is required!

I’m so proud and happy for everyone involved that we can now share this gorgeous dinosaur to the public! It’s MASSIVE. The fossils are just mind blowing to look at, and now we continue to move forward with its preservation, education, and further research. It’ll be going back to Argentina next year.

You can read the article about Dreadnoughtus here on Drexel University’s website, and the scientific paper on Nature.com (which some super awesome people I know worked on).

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Glass Fossils Inspire Molten Dreams
  • by Glendon Mellow

“When Mary Anning discovered the first fossil ichthyosaur skeleton along the Blue Lias cliffs of Dorset, could she have dreamed something like this? Amanda Heath is an art teacher and sculptor working in the mixed media of copper, glass and wood, and inspired by the Jurassic coast of Dorset.  Here are a few more pictures of the process of making the Glass Ichthyosaur. Her process is as wonderful to see as the final form. I might also note that when your artistic medium of choice is molten glass poured over shiny metal, you can use as much lens flare in your photography as you want. True story. And because I can’t help myself when it comes to trilobites, here’s a copper and glass one peeking its cephalon up from the grass. Thanks to Amanda Heath for sharing her work with us here on Symbiartic!”

(Source: Scientific American)

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older vs modern reconstructions

Helicoprion (“Spiral Saw”) was a long-lived genus of shark-like cartilaginous fish that first arose in the oceans of the late Carboniferous 280 million years ago, survived the Permian-Triassic Extinction Event, and eventually went extinct during the early Triassic, 225 million years ago.

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The only fossils known are the teeth, which were arranged in a fantastic “tooth-whorl” strongly reminiscent of a circular saw. It was not until the discovery of the skull of a relative, Ornithoprion, that it was realized that the tooth-whorl was in the lower jaw. The tooth-whorl represented all of the teeth produced by that individual in the lower jaw, in that as the individual grew, with the older, smaller teeth being moved into the center of the whorl by the appearance of larger, newer teeth. Comparisons with other eugenodontids suggest that Helicoprion may have grown up to 10-15 ft (3-4 m) long.

The exact location of the tooth-whorl in the lower jaw is an open debate. Older reconstructions placed the whorl in the front of the lower jaw; however this would create drag, making the shark a less efficient swimmer, and turbulence, alerting prey of its approach. A more current and scientifically accepted reconstruction places the whorl deeper into the throat. This arrangement would be best suited for soft bodied prey.

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Coloured modern reconstruction illustration [2] by Mary Parrish

Other images currently unsourced

New evidence suggests Archaeopteryx dressed in black.

Scientists have found a way to uncover feathered dinosaurs’ true colors, and one of the first creatures to come under inspection is none other than Archaeopteryx — an iconic but mysterious theropod believed by many to be the “missing link” between dinosaurs and birds.

Now, by examining a single, exceptionally well-preserved feather, one group of paleontologists believes it has the evidence it needs to weigh in on the color of Archaeopteryx's prehistoric plumage. This bird, say the researchers, wore black.

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By comparing the patterns of melanosomes contained within the Archaeopteryx feather (seen above) with the those found in the plumage of 87 similar, modern bird species, the researchers were able to determine that the feather was almost certainly black. What’s more, the researchers say Archaeopteryx's melanosomes would have provided its wings a structural advantage, as well.

"If Archaeopteryx was flapping or gliding, the presence of melanosomes would have given the feathers additional structural support,” said Ryan Carney, an evolutionary biologist at Brown and the paper’s lead author. “This would have been advantageous during this early evolutionary stage of dinosaur flight.”

Read the full article at io9.

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