Regumiel de la Sierra route
View the El Frontal site
Easily accessible and offering the option of leaving your vehicle, the El Frontal site in Regumiel de la Sierra allows us to learn about the world of dinosaurs through a replica over nine meters long and three meters high.
The El Frontal site has recorded 86 fossil tracks grouped into eight trails and separate impressions. Most of the tracks were made by iguanodontids, perhaps belonging to different individuals of the same species. One footprint has been identified as a small theropod (carnivorous or carrion eaters), that walked upright with long, narrow footsteps that displayed slender toes and sharp ends (claws).
Two footprints of quadrupeds stand out among the iguanodontids with three-toed "feet". They are wide, with short, stubby toes; the tracks left by the "hands" are oval-shaped. Some studies have proposed that it can be seen that two of the central fingers were joined together in those tracks while another finger remained separated from them. The lateral fingers, including the "thumb " or bone spur characteristic of iguanodontids, normally did not reach the ground.
The sandstone rocks where the fossil impressions at the site were preserved are plentiful in this region. They come from the sands deposited in the riverbeds and fluvial plains of the great rivers 125 million years ago. The dinosaurs had enough water and vegetation available there to drink and feed themselves in a subtropical climate. And in the sandy mud of those fluvial plains they left their footprints imprinted for posterity.
During the early Cretaceous period, the seas and oceans on Earth developed in an entirely different way from the ones we know today. The present day Iberian Peninsula was an island surrounded by seas that separated it from the rest of Europe.