Paleonews

Il blog dedicato ai Paleontologi !!!!

2008-11-14 – Montana, USA: nuovo “nido” di Teropodi (Theropod egg nest)

Darla Zelenitsky e Francois Therrien hanno descritto su Palaeontology un importante ritrovamento di un nido di piccoli Teropodi.

La scoperta è importante perchè tale nido presenta alcune caratteristiche (architettura del nido e morfologia delle uova) che ritroviamo negli uccelli attuali.

Nonostante l’importanza della scoperta va precisato che non si tratta nè del primo nido di Teropode in assoluto, ne tantomeno di piccoli Teropodi da cui si sarebbero evoluti gli uccelli.

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Public release date: 13-Nov-2008
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Contact: Leanne Yohemas
leanne.yohemas@ucalgary.ca
403-220-5144
University of Calgary

Dinosaur whodunit: Solving a 77-million-year-old mystery

University of Calgary and Royal Tyrrell Museum scientists close in on mother of one-of-a-kind fossil eggs

It has all the hallmarks of a Cretaceous melodrama. A dinosaur sits on her nest of a dozen eggs on a sandy river beach. Water levels rise, and the mother is faced with a dilemma: Stay or abandon her unhatched offspring to the flood and scramble to safety?

Seventy-seven million years later, scientific detective work conducted by University of Calgary and Royal Tyrrell Museum researchers used this unique fossil nest and eggs to learn more about how nest building, brooding and eggs evolved. But there is a big unresolved question: Who was the egg-layer?

“Working out who the culprit was in this egg abandonment tragedy is a difficult problem to crack,” says Darla Zelenitsky, U of C paleontologist and the lead author of a paper published today in the journal Palaeontology. “After further investigation, we discovered that this find is rarer than we first thought. It is a one of a kind fossil. In fact, it is the first nest of its kind in the world.”

Zelenitsky says she first saw the nest in a private collection which had been collected in Montana in the 1990s. The nest was labeled as belonging to a hadrosaur (duck-billed) dinosaur, but she soon discovered it was mistakenly identified. In putting all the data together, she realized they had a small theropod (meat-eating) dinosaur nest. “Nests of small theropods are rare in North America and only those of the dinosaur Troodon have been identified previously,” says Zelenitsky. “Based on characteristics of the eggs and nest, we know that the nest belonged to either a caenagnathid or a small raptor, both small meat-eating dinosaurs closely related to birds. Either way, it is the first nest known for these small dinosaurs.”

The nest tells scientists more about the behaviour of the animal as well as some valuable information relating to the characteristics of modern birds. “Our research tells us a lot about the dinosaur that laid the eggs and how it built its nest,” says Francois Therrien, a co-investigator in the study and curator of dinosaur palaeoecology at the Royal Tyrrell Museum in Drumheller, Alta.

The fossil nest is a mound of sand about half a metre across and weighing as much as a small person. The eggs were laid two at a time, on the sloping sides of the mound, and form a ring around its flat top, where the nesting dinosaur would have sat and brooded its clutch.

“Based on features of the nest, we know that the mother dug in freshly deposited sand, possibly the shore of a river, to build a mound against which she laid her eggs and on which she sat to brood the eggs,” says Therrien. “Some characteristics of the nest are shared with birds, and our analysis can tell us how far back in time these features, such as brooding, nest building, and eggs with a pointed end, evolved – partial answers to the old question of which came first, the chicken or the egg.”

 

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Notes to Editors:

Copies of the paper and high resolution version of an artists’ illustration of the nest and possible egg-laying dinosaurs are available for media use.

For more information contact:

Leanne Yohemas
Senior Communications Manager
Faculty of Science
University of Calgary
Office: 403-220-5144
Cell: 403-540-6552
leanne.yohemas@ucalgary.ca

source: http://www.sciencedaily.com/releases/2008/11/081113181200.htm

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Calgary Herald

Did dinosaur mum abandon her eggs?
Times of India – 5 ore fa
WASHINGTON: Seventy-seven million years ago, did a dinosaur mother sat on a nest of a dozen eggs on a sandy river bank, brooding whether to abandon the unhatched offspring to vagaries of nature and scramble to safety?
Alta. researchers find fossilized nest of small dinosaur Edmonton Sun
Alberta researchers reveal details of ‘one of a kind’ dinosaur nest CBC.ca
MSNBC – The Press Association – Reuters – Calgary Herald
e altri 45 articoli simili »

novembre 14, 2008 - Posted by | - R. Dinosauri, - Teropodi, - uova / eggs, 1 Cretaceo, America Northern, Articolo sc. di riferimento, Italiano (riassunto), P - Ritrovamenti fossili, Paleontology / Paleontologia

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