Jurassic beds of western Portugal: Almost Morrison

[Janet m vandenburgh <van02@cox.net>]

Jurassic beds of western Portugal: Almost Morrison

YourHub.com - Denver,CO,USA

Recent work by Portuguese paleontologists in the Portuguese Jurassic beds
has revealed the presence of dinosaur tracks, eggs, and embryos, ...

http://denver.yourhub.com/GreenwoodVillage/Events/Outdoors/Event~565032.aspx
YourHub.com \\  Greenwood Village \\  Events  \\  Outdoors 
Jurassic beds of western Portugal: Almost Morrison 

Contributed by: Friends of Dinosaur Ridge on 1/6/2009

What: Those familiar with Dinosaur Ridge know about the discovery of
Jurassic dinosaurs by Arthur Lakes in 1877 and, of course, the extensive
dinosaur trackway being preserved and maintained by FoDR. 

However, most of us know little about the discovery, 20 years later, of
contemporaneous dinosaurs along what is now the Atlantic coast of western
Portugal. About 70 km (43.3 miles) northwest of Lisbon, the Lourinha and
Alcobaca formations produced and continue to produce dinosaurs and other
fossils similar to those in the Morrison Formation in North America. Recent
work by Portuguese paleontologists in the Portuguese Jurassic beds has
revealed the presence of dinosaur tracks, eggs, and embryos, as well as a
number of new dinosaur taxa. 

The Lourinha-Alcobaca faunas are similar to the Morrison Fauna. The
portuguese formations contain similar charophytes, plants, molluscs,
ostracods, fish, amphibians, sphenodonts, crocodiles, snakes, lizards,
pterosaurs, mammals, and dinosaurs. 

This lecture on the dinosaurs of Portugal is not recommended for children. 

Where: 16831 W Alameda Pkwy, Morrison, CO 80465 
When: 7:00-8:30 PM 
Event Dates: This event takes place on 1/28/2009.
-----------------------------------------


How flying reptiles rose
MSNBC - USA
Unraveling the mysteries of pterosaur flight isn't merely an academic
exercise: Texas Tech paleontologist Sankar Chatterjee has been working with
...
http://cosmiclog.msnbc.msn.com/archive/2009/01/06/1734554.aspx

HOW FLYING REPTILES ROSE
Posted: Tuesday, January 06, 2009 7:05 PM by Alan Boyle
Mark Witton / U. of Portsmouth via JHU 
Giant pterosaurs were about the size of a modern-day giraffe.

How did a giant flying reptile get off the ground? It's not a simple
question: A computerized analysis of pterosaur fossils and modern-day bird
bones shows that the biggest pterosaurs couldn't simply lift off into the
air like a bird, because their hind legs were too weak.

The researcher behind the analysis says the forelimbs were much stronger -
so much stronger, in fact, that the creatures must have used their "arms" as
well as their legs to propel their leap into flight. But will that claim fly
with other experts? That remains to be seen.

The analysis is published in a special issue of the German-based journal
Zitteliana, and is the subject of a news release today from the Johns
Hopkins University School of Medicine.

Pterosaurs died off 65 million years ago in the same cataclysm that killed
off the dinosaurs on land and plesiosaurs at sea. So how can anyone possibly
know how they took off? Michael Habib, a researcher at the medical school's
Center for Functional Anatomy and Evolution, came up with a computerized
model for pterosaur flight dynamics by comparing data about bone strength
for three pterosaur species (Dorygnathus, Zhejiangopterus and Anhanguera ...
small, medium and large) with readings from 155 bird limb specimens.

Birds are built to leap into the air using their legs, and then flap their
wings for takeoff. But Habib found that pterosaurs were built differently.

"The difference between pterosaurs and birds with regard to critical
mechanical properties is very, very large, especially when you're talking
about the big pterosaurs," he said in the news release. "As the size gets
bigger, the difference gets bigger, too."

The model indicated that Anhanguera couldn't possibly launch itself using
its hind legs alone. That led Habib to suspect that the biggest pterosaurs
folded their wings and balanced on their "knuckles" to walk as well as to
push themselves off for flight. He envisioned the takeoff procedure as a
leap-frogging long jump. "Then, with wings snapping out, off they'd fly."

"Using all four legs, it takes less than a second to get off of flat ground,
no wind, no cliffs," he said. "This was a good thing to be able to do if you
lived in the late Cretaceous period and there were hungry tyrannosaurs
wandering around."

Unraveling the mysteries of pterosaur flight isn't merely an academic
exercise: Texas Tech paleontologist Sankar Chatterjee has been working with
aerodynamics experts to incorporate the critters' flying techniques into
next-generation aircraft. So he was interested to hear about the newly
published research.

"There are lots of pterosaur footprints which suggest that they walked
around on four legs," Chatterjee told me. But when it came to flying,
Chatterjee said giant pterosaur wings were so long that he doubted it could
be unfurled fast enough after a four-footed takeoff.

"The earlier it can clear off from the ground, the better," he said. For
that reason, he favors the idea that the biggest pterosaurs became airborne
the way hang gliders do: by jumping off a cliff or running down an incline
... on two legs.

Habib insists that his hypothesis is more flightworthy. Detailed studies of
bird takeoffs have shown that most of the power comes not from the flapping
wings, but from the initial leap. "Even in the most extreme cases, they'll
leap first, and then fly second," he told me.

No one can prove how pterosaurs took off, Habib said, but his findings
indicate that the pterosaurs should have been able to get their wings
unfolded and flapping quickly enough to keep them in the air. "I can
definitively demonstrate that it's plausible that they can flap," he said.

Mark Witton, a paleontologist at the University of Portsmouth who recently
identified a whole new genus of giant pterosaurs, said he sided with Habib.
Here's what he told me today in an e-mail:

"The idea that pterosaurs were weather- or topography-dependent for takeoff
and that they weren't strong flapping fliers - being essentially giant
gliders - ju  ...





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