Loarre, Castillos y Dinosaurios

Loarre is a small municipality in the province of Huesca with just over 300 residents owever it is world-famous for its castle a Romanesque fortress of the 12th century XI which has been stationed for more than a thousand years on the outer sierras watching over the Ebro Valley This castle is considered one of the most complete examples of Romanesque military architecture It is located in Europe and is visited by more than 100 000 people per year This incredible cultural heritage is further supported by a vast natural heritage where the Loarre mountain range is framed between the Riglos Mayos and the Eguara canyons They offer a great deal of tourist and cultural attraction for this population Recently a third major resource has been added the paleontological heritage With the discovery of the Loarre dinosaur egg site The outer ranges represent the southernmost Pyrenean territory they are located separated from the mountain range by about 70 kilometers The Pyrenees are a mountain range that began to rise as a result of The collision between the Iberian plate moving northward until it met the Eurasian plate This collision began approximately 80 million years ago toward the end of the Cretaceous It continued until the middle Miocene around 20 million years ago In this compressive process different layers of materials were stacked throug riding plans that allowed the lifting of mountains up to 3 000 Metros that we now find in the inner parts of the mountain range Since the Oligocene about 30 million years ago deformation began o spread from the inner part of the mountain range towards the south leading to the establishme From a shallow riding plate in what is now known as the exterior ranges In the Sierra del Oarre area we can see its internal structure through a A geological section that represents how the geometry of the layers beneath the surface looks As both the Pyrenees and the outer ranges were rising they were also being dismantled by erosive processes Therefore all those layers that had been stacked began to be eroded and transported oward the center of the Ebro Basin forming what is known as the Antepaís Bas Represented here by the Mayos de Ríos conglomerates On the northern flank of the southern range of outer hills we can see the layers They are flowing northward in a monoclinic series that ends by connecting to the Jaca Turbidite Basin In the northern part of the outer ranges we can see the uplifted block of the surpirinaic thrust In it we find a series of materials trending north that encompass Triassic Cretaceous and Tertiary materials In the lower part of this ride we can see that the structure is more complex Existing different overlapping and interlocked riding layers that deform these Mesozoic and Tertiary materials In some places the thrusts are blind and overlay the Mesozoic series over the series In some cases the contact is simply a discordance between them Finally to the south we see how the materials overlap Outer ranges over the conglomerates of the Ebro Basin The discovery of the Logarre dinosaur site has a unique story because it was not found in a conventional way during a field campaign for prospecting There were no previous paleontological indications of this type of dinosaur egg site in the Sierra de Logarre area It took place during a routine training session with the University Alpine Club From the University of Zaragoza taking a walk through the Sierra de Logarre We had planned a route starting from Logarre Castle going around by ascending up to the Puchilibro the highest hill in the sierra and at one point during the journey We were passing through an area with reddish outcrops I know the area of the Pre-Pyrenees and the countryside from having walked through it before Field sites that we have made easy to access are favorable for housing vertebrate fossils And when I come across an outcrop sometimes I like to take a look just in case something shows up And in this particular exit during a break we took I found myself by the side of the road In a very noticeable reddish outcrop I looked down and suddenly there was a surprise It was full of eggshells Then at that moment I was surprised that this was something unusual because it was that I had never we had found similar evidence in this area of Aragon so I took the Coordinates of the point I took some photos at that moment we continued the excursion but quickly I got in touch with the colleagues in the paleontology department especially w Miguel Moreno the eggshell expert because we had to reassess The site because it was clearly a very promising site But José Manuel was not the first geologist to identify dinosaur eggs in the e outer sierras of Huesca In 1967 Pierre Souquet discovered a site right next to the La Peña reservoir while He was working on his doctoral thesis At the road cut leading up to La Peña reservoir Pierre Souquet identified a A 50-meter series of red clays where he found some small black calcium carbonate fragments Expert in the dinosaur eggs of Col de Nargó identified these shells correctly as fragments of titanosaur eggs which allowed him to confirm the Maastrichtian age of these outcrops The description of this outcrop by Pierre was three lines in a thesis of more than a thousand Pages about the Mesozoic and Cenozoic eras of the Peruvian Andes These three lines went unnoticed for almost 50 years in a 1 100-page thesis pages covering the Mesozoic and Cenozoic of the outer ranges The eggs found by Pierre Souquet in 1967 and the eggs we have found In Santa Marina they belong to the same species Megalodon siruguei This is done because the dinosaur eggs from Col de Nargó which are the These two outcrops are more than 8 kilometers apart in a straight line and furthermore in all the points where outcrops appear between these two outcrops we have found shell fragments of the same type This suggests that the fossil-bearing band may extend for more than 10 kilometers In the area of the Hermitage of Santa Marina we find deposits from the Upper Cretaceous It is a mastigating creature dating back between 68 and 66 million years The lower part consists of carbonate deposits representing shallow seas while The upper part of reddish tones known as facies garum are continental deposits of alluvial plains The transition between them corresponds to a regression that is an advance of the continental systems over the marine areas After the spectacular discovery by José Manuel we quickly returned to the site to assess its contents and were amazed The entire site which is about 200 square meters was completely covered with large dinosaur eggshell fragments We didn't take long to find it a semi-circular shell structure in the rock that suggested there might be an egg inside When we prepared the block and then excavated it were in for a big surprise at the site There were full dinosaur eggs about 20 centimeters in size covered with shells This is our zero egg the first egg we retrieved from the Santa Marina site The work at the Santa Marina Hermitage site is a bit different from other vertebrate sites The main problem we have is that the interlocking rock is very hard so the Usual methods of using small chisels and brushes do not work We have to work using pneumatic hammers and large chisels for the initial approach and then drilling into the rock to extract the mummies That is as always the excavation is perfectly documented using a reference system with a theodolite and grids to draw each of the egg accumulations The site covers an area of about 200 square meters and we have found up to 7 egg accumulations there Each of these clusters contains between 6 and 12 eggs and we think they could be potential ones Dinosaur nests but we still have to work to prepare them and find out if there are still more eggs Well one of the objectives we have when studying this site is to see If these 6 or 7 egg accumulations are nests or just accidental accumulations because the eggs have moved due to things of They may have been moved by currents or by some other animal or may have accumulated in one part of the site To answer this question we will study among other things for example e arrangement of the eggs in these accumulations whether they are all ordered whether they are oriented In some way we will also study the sediment surrounding these eggs and see if it is slightly different from the sediment where there are no eggs Then by comparing the sediment arrangement and these accumulations we will be able to try to answer hopefully this very interesting question In addition to the main nesting area where we found titanosaur sauropod eggs In the red clays you see on the site we have washed sediment and in this sedime Theropod dinosaur eggshells from the genus Prismatolitus are appearing y pseudogoecolitus as well as alligator shells and possibly turtle shells The materials in which the deposit is found correspond to deposits Fine terrigenous sediments that settled on the adjacent plains of major rivers These plains were periodically flooded by the overflow of the river channels When the water spread across the plains its energy was reduced and the materials settled by suspension to the bottom When these plains were exposed to aerial conditions the materials oxidized due to contact with the air while at times when they were The conditions were anoxic and oxidation-reduction processes occurred These changes and fluctuations in the water layer also facilitated the establishme of plants and vegetation which we can observe today as nodules and bioturbations that have altered the initial structure of the deposit The structure of the eggshell from the Oarre site eggs is very interesting We have eggshells that are between 2 and 3 millimeters thick although we have found some fragments over one centimeter that would probably represent the shells e thickest eggshells in the fossil record which are probably pathological or due to processes that have altered the shell structure But normal shells have a distinct and spherical structure with a surface compact and tuberculate formed by clusters of very closely packed shell units tightly packed together The pore system is tubular and does not have any secondary pore system at one of the vertical pores is which is a surprise because all these features cluding the thickness the type of shell structure they resemble the species Megalolitus sergeant a dinosaur egg that was first found in southern France And also in deposits in Catalonia such as those in Balsebre and Col de Nargó This shell structure has traditionally been interpreted as eggshell structures anosaur dinosaurs these long-necked long-legged sauropods with four legs of the Aldieta herbivorous species and that would lay their eggs throughout the Pyrenees and Even in other parts of Europe such as Romania It is very interesting about these dinosaurs that despite there being a relatively diverse Small in number of eggs because across the entire European continent we have found only two or three different confirmed species seven species of dinosaurs have been found Golden-footed creatures in the Pyrenees some still to be described Possible candidates for having laid the eggs of the Logarre site are dinosaurs Like Ampelosaurus this armored titanosaur which we see here or others like Achinianosaurus Garrigatitan or Loguecotitan recently described in Cuenca There is still a lot of work to be done we have many full eggs as I told you before ey are similar to those in Lleida in Col de Nargó and in Balsebre but the faces They are different the preservation from the shell is different and this lack of a secondary system They mean that it is probably a similar species but not exactly the same as in Col de Nargó There is still much work to be done including searching for embryos inside the eggs we have not found any yet othing but we have already started scanning different eggs to see if we are lucky and if so we need to continue the investigation to further explore these findings An international collaboration resulting from the cooperation and agreement between the University of Zaragoza and the New University of Lisbon with the support of the Museum of Lourgnan opens a series of comparison windows for various types of dinosaurs various ages and various forms of biology and ecology of a specific species This gives us an international perspective on paleontology and is an excellent example A Iberian collaboration between the universities of Portugal and Spain For me excavating here in Iperenei is a wonderful experience especially because As a young paleontologist the opportunity to excavate this exceptional site is something unique and irreplaceable I'm from Loar and I study geology so it's a lucky thing that it's so close to home I find a site where I can learn a lot of knowledge and gain more experience For me the big difference between the excavations here in Loar and the excavations I have done elsewhere is the level of community involvement I'm used to it because we usually dig up large dinosaur bones Here we are working with a more delicate material such as eggshells Another difference is that here we work in a horizontal position whereas Normally I'm hanging by the wires above the sea so the view here is more pleasant As a paleontologist I have had to excavate in very different conditions ranging from mountainous areas to hanging cliffs over 20 meters high and I have to adm one of the most demanding physical and technical conditions of the Loar site e most difficult conditions I have ever faced as they require the use of machines As if saws pneumatic hammers and even we will have to remove the mummies The use of machinery such as cranes and excavators has made plaster jackets possible The next step in the research is clear Now all those mummies we have removed from the site need to be prepared and restored in order to advance our research There is a lot of work to be done but one thing we have decided to do is do it here Same in Loarre in this that you see behind which is the Loarre paleontological laboratory Here we are building a small preparation laboratory that will be accompanied by some museum rooms where we will display new discoveries Today the lab is still under construction but starting in 2022 you are all invited Discover how our research continues in the dinosaur egg laboratory of Loarre In the past 15 years I have worked searching for dinosaur eggs in four continents and a dozen countries and finally the best deposit I have ever known was A 20 kilometers from the house where I was born from which I can see my parents' house from the site It is difficult to explain in words how important this site is not only for our team but also for paleontology in general in the Iberian Peninsula Two years ago no one associated Loarre with dinosaurs but now we are facing a site that could become an international reference The paleontological potential of the Loarre site combined with the cultural heritage It represents the castle and the natural heritage of the outer sierras and it is a unique opportunity to promote geotourism in the area