Navigation Links
Fossil egg discovered in Lleida (Spain) links dinosaurs to modern birds
Date:7/12/2012

Before her death in December 2010, Nieves Lpez Martnez, palaeontologist of the Complutense University of Madrid, was working on the research of dinosaur eggs with a very peculiar characteristic: an ovoid, asymmetrical shape. Together with Enric Vicens, palaeontologist of the Universitat Autnoma de Barcelona, the two scientists conducted an exhaustive analysis of their discovery, recently published in the journal Palaeontology.

The new type of dinosaur egg has been given the scientific name of Sankofa pyrenaica. The eggs were discovered in the Montsec area of Lleida, in two sites located on either side of the Terradets pass.

The South Pyrenean area is rich in dinosaur egg sites, most of which correspond to sauropod eggs from the upper Cretaceous, dating back more than 70 million years ago. During that period, the area was a coastal area full of beaches and deltas which won land from the sea through sediment accumulation. Sand and mud from that period gave way, millions of years later, to the sandstone and marl where dinosaur remains now can be found. On the beach ridges and flat coastal lands is where a large group of dinosaurs laid their eggs.

The sites where the discoveries were made correspond to the upper Cretaceous, between the Campanian and Maastrichtian periods, some 70 to 83 million years ago. The fossils found belong to small eggs measuring some 7 centimetres tall and 4 cm wide, while the eggshell was on average 0.27mm thick. Most of the eggs found were broken in small fragments, but scientists also discovered more or less complete eggs, which can be easily studied in sections. The eggs found at the sites all belong to the same species. The main difference when compared to other eggs from the same period is their asymmetrical shape, similar to that of chicken eggs. The more complete samples clearly show an oval form rarely seen in eggs from the upper Cretaceous period and similar to modern day eggs.

Their shape is a unique characteristic of theropod eggs from the upper Cretaceous period and suggests a connection with bird eggs. Non avian dinosaur eggs are symmetrical and elongated. Asymmetry in bird eggs is associated to the physiology of birds: they take on this shape given the existence of only one oviduct which can form only one egg at a time. In this case the isthmus, the region in the oviduct creating the eggshell membrane, is what gives the egg its asymmetrical shape. Thanks to this shape, the wider end contains a bag of air which allows the bird to breathe in the last stages of its development. This evolutionary step was still relatively underdeveloped in dinosaurs.

Thus, the egg discovered by UCM and UAB researchers in certain manners represents the missing link between dinosaurs and birds. Only one other egg, discovered in Argentina and corresponding to a primitive bird from the same period, has similar characteristics. The discover represents proof in favour of the hypothesis that non avian theropods, the dinosaurs of the Cretaceous period, and birds could have had a common ancestor.


'/>"/>
Contact: Enric Vicens
Enric.vicens@uab.cat
34-935-811-783
Universitat Autonoma de Barcelona
Source:Eurekalert

Related biology news :

1. Fossil turtle from Colombia round like car tire
2. Work starts on fossil fuel free cargo ship set to transform shipping industry
3. Human-like spine morphology found in aquatic eel fossil
4. Scientists find gold-plated fossil solution
5. Ancient giant turtle fossil revealed
6. Anthropologist finds explanation for hominin brain evolution in famous fossil
7. Buy coal? New analysis shows purchasing fossil fuel deposits best way to fight climate change
8. Seismic zones, river deltas, landslides, fossil reptiles, and more new Geology science
9. Dinosaur fossil: Even specialized predators didnt turn down free meals
10. Protecting living fossil trees
11. Can you hear me now? New strategy discovered to prevent hearing loss
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:6/16/2016)... June 16, 2016 The ... expected to reach USD 1.83 billion by 2024, ... Research, Inc. Technological proliferation and increasing demand in ... expected to drive the market growth. ... The development of advanced multimodal techniques for ...
(Date:6/3/2016)... LONDON , June 3, 2016 /PRNewswire/ ... Transport Management) von Nepal ... ,Angebot und Lieferung hochsicherer geprägter Kennzeichen, einschließlich ... weltweit führend in der Produktion und Implementierung ... an der Ausschreibung im Januar teilgenommen, aber ...
(Date:5/24/2016)... Ampronix facilitates superior patient care by providing unparalleled technology to leaders of the medical ... premium product recently added to the range of products distributed by Ampronix. ... ... ... Ampronix News ...
Breaking Biology News(10 mins):
(Date:6/22/2016)... Research and Markets has announced the addition of the ... The global biomarkers market has ... The market is expected to grow at a five-year compound annual ... $50.6 billion in 2015 to $96.6 billion in 2020. ... to 2020) are discussed. As well, new products approved in 2013 ...
(Date:6/22/2016)... LOS ANGELES , June 22, 2016   ... an SNNLive Video Interview with Dr. Nader Pourhassan ... a biotechnology company focused on the clinical development and ... and prevention of HIV infection, according to the company,s ... was recorded on Tuesday, June 7 th , 2016, ...
(Date:6/22/2016)... DIEGO , June 22, 2016   ViaCyte, ... first pluripotent stem cell-derived islet replacement therapy for the ... presentations at ISSCR 2016 Annual Meeting.  ISSCR 2016, the ... to 25th at Moscone West in San Francisco.  ... of the presentations are as follows:Event: , Focus Session: ...
(Date:6/22/2016)... (PRWEB) , ... June 22, 2016 , ... ... at placing a spotlight on immigrant achievements and contributions to North Texas and ... most important contributors from the immigrant community to the civic and economic vitality ...
Breaking Biology Technology: