Subscribe free to our newsletters via your
. 24/7 Space News .




EARLY EARTH
Jurassic jaws: How ancient crocodiles flourished during the age of the dinosaurs
by Staff Writers
Bristol UK (SPX) Sep 16, 2013


A sample of jaws from the Mesozoic crocodile fossil record.

New research has revealed the hidden past of crocodiles, showing for the first time how these fierce reptiles evolved and survived in a dinosaur dominated world.

While most modern crocodiles live in freshwater habitats and feed on mammals and fish, their ancient relatives were extremely diverse - with some built for running around like dogs on land and others adapting to life in the open ocean, imitating the feeding behaviour of today's killer whales.

Research published today [11 September] in the journal Proceedings of the Royal Society B shows, for the first time, how the jaws of ancient crocodiles evolved to enable these animals to survive in vastly different environments, all whilst living alongside the dinosaurs 235 to 65 million years ago.

The study was conducted by Tom Stubbs and Dr Emily Rayfield from the University of Bristol, together with Dr Stephanie Pierce from The Royal Veterinary College and Dr Phil Anderson from Duke University.

Tom Stubbs, who led the research at the University of Bristol, said: "The ancestors of today's crocodiles have a fascinating history that is relatively unknown compared to their dinosaur counterparts. They were very different creatures to the ones we are familiar with today, much more diverse and, as this research shows, their ability to adapt was quite remarkable.

"Their evolution and anatomical variation during the Mesozoic Era was exceptional. They evolved lifestyles and feeding ecologies unlike anything seen today."

The research team examined variation in the morphology (shape) and biomechanics (function) of the lower jaws in over 100 ancient crocodiles, using a unique combination of numerical methods.

Dr Stephanie Pierce, from The Royal Veterinary College, said: "We were curious how extinction events and adaptations to extreme environments during the Mesozoic - a period covering over 170 million years - impacted the feeding systems of ancient crocodiles and to do this we focused our efforts on the main food processing bone, the lower jaw."

By analysing variation in the lower jaw, the researchers provide novel insights into how the feeding systems of ancient crocodiles evolved as the group recovered from the devastating end-Triassic extinction event and subsequently responded to the distribution of ecological resources, such as habitat and foodstuff.

For the first time, the research has shown that, following the end-Triassic extinction, ancient crocodiles invaded the Jurassic seas and evolved jaws built primarily for hydrodynamic efficiency to capture agile prey, such as fish. However, only a small range of elongate lower jaw shapes were suitable in Jurassic marine environments.

The study has also revealed that variation peaked again in the Cretaceous, where ancient crocodiles evolved a great variety of lower jaw shapes, as they adapted to a diverse range of feeding ecologies and terrestrial environments, alongside the dinosaurs.

Surprisingly, the lower jaws of Cretaceous crocodiles did not have a great amount of biomechanical variation and, instead, the fossil record points towards novel adaptations in other areas of their anatomy, such as armadillo-like body armour.

Dr Pierce added: "Our results show that the ability to exploit a variety of different food resources and habitats, by evolving many different jaw shapes, was crucial to recovering from the end-Triassic extinction and most likely contributed to the success of Mesozoic crocodiles living in the shadow of the dinosaurs."

This exceptional variation has never before been explored numerically, with no studies ever having incorporated such a wide range of crocodiles over such a long time period.

.


Related Links
University of Bristol
Explore The Early Earth at TerraDaily.com






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle








EARLY EARTH
Researchers identify ancient ancestor of tulip tree line
Bloomington IN (SPX) Sep 16, 2013
The modern-day tulip tree, state tree of Indiana as well as Kentucky and Tennessee, can trace its lineage back to the time of the dinosaurs, according to newly published research by an Indiana University paleobotanist and a Russian botanist. The tulip tree, Liriodendron tulipfera, has been considered part of the magnolia family. But David Dilcher of Indiana University Bloomington and Mikha ... read more


EARLY EARTH
Sixteen Tons of Moondust

Scientists say water on moon may have originated on Earth

Moon landing mission to use "secret weapons"

NASA launches spacecraft to study Moon atmosphere

EARLY EARTH
Explosive flooding said responsible for distinctive Mars terrain

Upgrade to Mars rovers could aid discovery on more distant worlds

Investigating 'Coal Island' Rock Outcrop

Terramechanics research aims to keep Mars rovers rolling

EARLY EARTH
NASA Spacecraft Embarks on Historic Journey Into Interstellar Space

Elite Group of Young Scientists Embark on DARPA Research Efforts

From Elvis to E.T.? The Voyagers' extraordinary tale

Astronauts prepare for deep space -- by going deep underground

EARLY EARTH
China civilian technology satellites put into use

China to launch lunar lander by end of year: media

China launches three experimental satellites

Medical quarantine over for Shenzhou-10 astronauts

EARLY EARTH
ISS Releases a White Stork and Awaits a Swan

Three astronauts back on Earth from ISS: mission control

ISS Crew Completes Spacewalk Preps

Russian cosmonaut set for space station mission resigns

EARLY EARTH
Arianespace remains the global launch services leader

Russian space official denies report of problem in Soyuz return

Lockheed Martin Atlas V To Launch Morelos-3 ComSat

Japan sets new date for satellite rocket launch

EARLY EARTH
ESA selects SSTL to design Exoplanet satellite mission

Coldest Brown Dwarfs Blur Lines between Stars and Planets

NASA-funded Program Helps Amateur Astronomers Detect Alien Worlds

Observations strongly suggest distant super-Earth has water atmosphere

EARLY EARTH
Butterfly wings inspire new technologies: from fabrics and cosmetics to sensors

Calculating the carbon footprint of California's products

First laser-like X-ray light from a solid

Space's 'Ferrari' set to fall to Earth




The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement