. 24/7 Space News .
EARLY EARTH
Taking dinosaur temperatures with eggshells
by Staff Writers
Pasadena CA (SPX) Oct 20, 2015


A large clutch of titanosaur eggs has been cleaned for research. Image courtesy Luis Chiappe, LA County Natural History Museum. For a larger version of this image please go here.

Researchers know dinosaurs once ruled the earth, but they know very little about how these animals performed the basic task of balancing their energy intake and output--how their metabolisms worked. Now, a team of Caltech researchers that has measured the body temperatures of a wide range of dinosaurs has provided insight into how the animals may have regulated their internal heat.

The study was led by John Eiler, the Robert P. Sharp Professor of Geology and professor of geochemistry, and Rob Eagle, a former Caltech postdoctoral scholar now at UCLA. A paper describing the research appears in the October 13 issue of the journal Nature Communications.

The current study examined eggshells from the sauropods, a group that includes some of the biggest dinosaurs ever to live, called Titanosaurs, as well as eggshells of birdlike and approximately human-sized oviraptorid dinosaurs. The eggshells were analyzed to determine the extent to which carbon-13 and oxygen-18--rare, naturally occurring isotopes (variant forms of elements that differ in number of neutrons)--group together in the mineral structure.

This "clumping" of rare isotopes previously has been shown to depend on mineral growth temperature. The eggshell data were compared with the results of a previous study by this same group that used similar techniques to examine the growth temperatures of the sauropod dinosaurs, including the giraffe-like Giraffatitan and a giant herbivore known as Camarasaurus.

The isotopic composition of the eggshells showed that smaller oviraptorid dinosaurs had body temperatures of 32 degrees Celsius--decidedly cooler than modern mammals and birds. The body temperatures of the larger Titanosaur dinosaurs were 38 degrees Celsius, indistinguishable from a previous finding for Giraffatitan teeth and similar to modern mammals.

This finding--that larger dinosaurs maintained body temperatures like ours whereas smaller ones more closely resembled modern reptiles--has implications for our understanding of dinosaur physiology.

Modern mammals are described as warm blooded if they regulate their own temperature, as if tweaking an internal thermostat. In a process called endothermy, warm-blooded mammals utilize the heat generated by their own internal functions instead of drawing ambient heat from the environment, which is what a cold-blooded snake or lizard does by basking in the sun. Endothermy is relatively similar across many different sizes of mammals, from mice to humans to whales.

"Measuring cooler temperatures in small dinosaurs is the first evidence to suggest that at least some of them had lower basal metabolisms than most modern mammals and birds, and therefore the emergence of modern mechanisms of endothermy hadn't occurred in these dinosaurs," Eiler says.

The picture is not so clear for the larger dinosaurs that were studied. Although Eiler and his colleagues found that they had warm body temperatures similar to modern mammals, it is not known if the animals actually had endothermic metabolisms or if they were warm simply because of their enormous sizes--a phenomenon known as gigantothermy.

Gigantotherms have small surface areas relative to their large volumes and thus have less area through which they can lose heat. Therefore, the heat is trapped internally. "If you weigh 80 tons, your problem is not staying warm--it's trying not to burst into flames," Eiler says.

The wide range of warm temperatures discovered among the various dinosaur species examined in the study suggests that "either they had a range of different metabolic strategies, or they all had low basal metabolisms, and the large ones were only warm due to gigantothermy," Eiler says.

The technique used to determine these animal body temperatures was first conceived and used by Eiler's group in 2011 on dinosaur tooth fossils and is related to methods they previously developed for nonbiological minerals and molecules. The method, called the clumped-isotope technique, relies on measurements of rare isotopes in bioapatite, or biologically grown calcium carbonate, a mineral present in bones, teeth, eggshells, and other fossils.

In 2006, Eiler's lab quantified the degree to which carbon-13 and carbon-18 clump together to varying degrees in a biomineral, depending on the temperature at the time the mineral formed; this relationship subsequently was examined for many mineral types by Eiler's group at Caltech and at other laboratories.

"There's this cool idea that if I had a fossil skeleton, I could map the body temperature of the entire creature and come up with a physiological model of how it redistributed heat within its body," Eiler says. "There's no reason you couldn't do that, except that bone isn't very well preserved."

The team's next step is to compare fossils from the same species across stages of maturation. "It may be that some dinosaurs have a different metabolic strategy at different phases of life," Eiler says.


Thanks for being here;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.
SpaceDaily Contributor
$5 Billed Once


credit card or paypal
SpaceDaily Monthly Supporter
$5 Billed Monthly


paypal only


.


Related Links
California Institute of Technology
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

Previous Report
EARLY EARTH
125M year-old mammal fossil reveals the early evolution of hair and spines
Chicago IL (SPX) Oct 15, 2015
The discovery of a new 125-million-year-old fossil mammal in Spain has pushed back the earliest record of preserved mammalian hair structures and inner organs by more than 60 million years. The specimen, named Spinolestes xenarthrosus, was fossilized with remarkably intact guard hairs, underfur, tiny hedgehog-like spines and even evidence of a fungal hair infection. The unusually well-pres ... read more


EARLY EARTH
Mound near lunar south pole formed by unique volcanic process

Lunar Pox

Space startup confirms plans for robotic moon landings

Asteroids found to be the moon's main 'water supply'

EARLY EARTH
Opportunity parked for solar panels to charge up for winter

Pebbles on Mars likely traveled tens of miles down a riverbed

To save on weight, a detour to the moon is the best route to Mars

Opportunity working at 'Marathon Valley' before winter relocation

EARLY EARTH
Brands eye big bucks with 'Back to the Future' nostalgia

Russian Cosmonauts Taste 160 Meals Ahead of Space Station Expedition

NASA, Israel ink space cooperation agreement

Magnetic sail tech alternative to rocket-based space travel

EARLY EARTH
Latest Mars film bespeaks potential of China-U.S. space cooperation

Exhibition on "father of Chinese rocketry" opens in U.S.

The First Meeting of the U.S.-China Space Dialogue

China's new carrier rocket succeeds in 1st trip

EARLY EARTH
RSC Energia patented inflatable space module for ISS

Clearing the Space Fog on ISS

International Space Agencies Meet to Advance Space Exploration

Meet the International Docking Adapter

EARLY EARTH
China puts new communication satellite into orbit for HK company

ISRO to Launch 6 Singapore Satellites in December

ILS Proton Launches Turksat 4B

Both passengers for next Ariane 5 mission arrive in French Guiana

EARLY EARTH
Airbus DS ready to start testing exoplanet tracker CHEOPS

Hubble Telescope Spots Mysterious Space Objects

Exoplanet Anniversary: From Zero to Thousands in 20 Years

Mysterious ripples found racing through planet-forming disc

EARLY EARTH
'Molecular accordion' drives thermoelectric behavior in promising material

Is black phosphorous the next big thing in materials

Mode control for square microresonator lasers suitable for integration

Boeing showcases lightest metal ever









The content herein, unless otherwise known to be public domain, are Copyright 1995-2024 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news 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. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. 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. General Data Protection Regulation (GDPR) Statement Our advertisers use various cookies and the like to deliver the best ad banner available at one time. All network advertising suppliers have GDPR policies (Legitimate Interest) that conform with EU regulations for data collection. By using our websites you consent to cookie based advertising. If you do not agree with this then you must stop using the websites from May 25, 2018. Privacy Statement. Additional information can be found here at About Us.