Navigation Links
Four, three, two, one . . . pterosaurs have lift off
Date:1/6/2009

Pterosaurs have long suffered an identity crisis. Pop culture heedlessly and wrongly lumps these extinct flying lizards in with dinosaurs. Even paleontologists assumed that because the creatures flew, they were birdlike in many ways, such as using only two legs to take flight.

Now comes what is believed to be first-time evidence that launching some 500 pounds of reptilian heft into flight required pterosaurs to use four limbs: two were ultra-strong wings which, when folded and balanced on a knuckle, served as front "legs" that helped the creature to walk and leap.

Publishing in Zitteliana, Michael B. Habib, M.S., of the Center for Functional Anatomy and Evolution at the Johns Hopkins University School of Medicine, reports his comparison of bone strength in the limbs of pterosaurs to that of birds and concludes that pterosaurs had much stronger "arms" than legs. The reverse is true of birds.

"We've all seen birds take off, so that's what's most familiar," says Habib. "But with pterosaurs, extinct 65 million years and with a fossil history that goes back 250 million years, what's familiar isn't relevant."

A supersized glitch is inherent in the traditional bipedal launch model, Habib notes: "If a creature takes off like a bird, it should only be able to get as big as the biggest bird."

Birds use legs to launch, wings to flap. They don't get launch power from wings or flight power from legs. In fact, when a bird is aloft, its legs become payload, or cargo. The muscle on the two back limbs that provides the power to launch must be carried and therefore limits size. Released of that handicap by employing all four legs to launch, giant pterosaurs could fly despite the fact that they were roughly the same size and shape as modern-day giraffes.

"The difference between pterosaurs and birds with regard to critical mechanical properties is very, very large," Habib says, especially when you're ta
'/>"/>

Contact: Maryalice Yakutchik
myakutc1@jhmi.edu
443-287-2251
Johns Hopkins Medical Institutions
Source:Eurekalert

Page: 1 2

Post Your Comments:
*Name:
*Comment:
*Email:
(Date:6/17/2015)... 17, 2015  Crossmatch™, a leading provider of ... U.are.U ® 4500 fingerprint readers have been ... Inc., a San Jose, CA ... security, improve accountability and reduce fraud at the ... identity confirmation for employee sign in and transaction ...
(Date:6/16/2015)... YORK , June 16, 2015  With the ... world, security remains a top concern. The recent compromise ... confirms the need for strong authentication within government agencies. ... Token, a biometric one-time password (OTP) authenticator, has been ... Standards (FIPS) 140-2 Level 3 validation for tamper proofing. ...
(Date:6/16/2015)... 16, 2015 Fingerprint Cards (FPC) raises ... it will amount to at least 340 MSEK to that ... rapid increase in market growth and orders received the revenue ... that revenue for 2015 will exceed 1,500 MSEK to an ... 2,200 MSEK. Due to receipt of orders of ...
Breaking Biology News(10 mins):Togo's Eateries Improve Security and Accountability with Crossmatch Fingerprint Readers 2Togo's Eateries Improve Security and Accountability with Crossmatch Fingerprint Readers 3Government Ready Biometric Security Approaching as HYPR Corp. Files FIPS 140-2 Level 3 Validation for Its Proprietary Biometric Token 2Government Ready Biometric Security Approaching as HYPR Corp. Files FIPS 140-2 Level 3 Validation for Its Proprietary Biometric Token 3Fingerprint Cards Raises the Revenue Guidance for Q2 2015 and for the Full Year 2015 2Fingerprint Cards Raises the Revenue Guidance for Q2 2015 and for the Full Year 2015 3
... to the future of the oceans, suggests a new report ... 8th issue of Current Biology, a publication of Cell Press. ... first evidence that the health of the deep sea, as ... with the diversity of species living there. For the ...
... in the numbers of copies of genes, occur when ... stalls and then switches to a different genetic template, ... in a report that appears today in the journal ... Stalling and Template Switching, said Dr. James R. Lupski, ...
... research published online this week in the open-access journal ... the fruit fly, and comes to a surprising new ... on the presence of the Y chromosome, which is ... But other animal groups have evolved different systems. James ...
Cached Biology News:Deep-sea species' loss could lead to oceans' collapse, study suggests 2Copy number variation may stem from replication misstep 2Copy number variation may stem from replication misstep 3
(Date:6/29/2015)... 29, 2015 Elsevier , ... products and services, today announced the highlights of its ... 2014 Journal Citation Reports® (JCR) published by Thomson Reuters, ... from 2013 to 2014, ahead of the aggregate across ... rank in 62 subject categories, up from 61 in ...
(Date:6/26/2015)... June 26, 2015  A San Francisco company, Pembient, ... with synthetic rhino horn: beer in China ... . In response to the emerging industry, two ... and sale of synthetic rhino horn.  ... Save the Rhino International (SRI) released a ...
(Date:6/26/2015)... The report "Biolubricants Market by ... fluids, Chainsaw oils, Mold Release Agents), End Use (Industrial, ... trends and Forecasts to 2020" published by MarketsandMarkets, The ... 2020 at a CAGR of 6.27% between 2015 and ... and   66 Figures spread through 170 Pages and ...
(Date:6/25/2015)... ... 25, 2015 , ... The American Brain Tumor Association announced ... Family Conference, Providing and Pursuing Answers: Advances in Research, Treatment and Care. The ... July 24-25, 2015. , “As advances in research accelerate the arrival of precision ...
Breaking Biology Technology:Elsevier Announces 2014 Citation Impact Highlights 2Elsevier Announces 2014 Citation Impact Highlights 3Rhino Experts Oppose Synthetic Rhino Horn as Solution to Poaching Crisis 2Biolubricants Market Worth $2,972.13 Million by 2020 2Biolubricants Market Worth $2,972.13 Million by 2020 3Nationally Recognized Brain Tumor Experts to Speak at American Brain Tumor Association Patient and Family Conference 2
... Optimer Pharmaceuticals, Inc. (Nasdaq: OPTR ) today announced ... phase 3 study at the 47th Annual Meeting of ... PA. , (Logo: http://www.newscom.com/cgi-bin/prnh/20090413/LA97352LOGO ) , ... Infectious Diseases, Chair of the Infection Prevention and Control ...
... ThermoGenesis Corp. (Nasdaq: KOOL ), a leading ... cells, announced today it will report financial results for the ... 5, 2009. , Company,s Conference Call and ... Thursday, November 5, 2009 at 2:00 PM Pacific (5:00 PM ...
... LAKE, N.J., Oct. 30 Eisai Inc. today announced ... with eribulin mesylate (E7389), discovered and developed by the ... cancer. , This global Phase III study, known as ... Versus E7389), was an open-label, randomized, parallel two-arm, multi-center ...
Cached Biology Technology:Additional Data From Fidaxomicin's Phase 3 Study for Clostridium Difficile Infection (CDI) Presented at IDSA Annual Meeting 2Additional Data From Fidaxomicin's Phase 3 Study for Clostridium Difficile Infection (CDI) Presented at IDSA Annual Meeting 3Additional Data From Fidaxomicin's Phase 3 Study for Clostridium Difficile Infection (CDI) Presented at IDSA Annual Meeting 4Thermogenesis Corp. to Announce First Quarter Fiscal 2010 Results on November 5, 2009 2Global Phase III Study Results Show Eribulin Meets Primary Endpoint of Overall Survival 2Global Phase III Study Results Show Eribulin Meets Primary Endpoint of Overall Survival 3Global Phase III Study Results Show Eribulin Meets Primary Endpoint of Overall Survival 4
Mol wt: monoisotopic mol wt1,045.5423 Da by calculation...
Bis-Acrylamide (bis) is a monomer used as a crosslinker with acrylamide to form polyacrylamide electrophoretic gels. This 2% bis solution is supplied as 500 ml....
Anti-human VEGFR-2/KDR (Protein-A Purified) Polyclonal Antibody...
Mouse monoclonal antibody to Lats2....
Biology Products: