(TERUEL, Spain) - An open pit coal mine near the town of Ariño, Spain has resulted in the discovery of the most completely preserved ankylosaur ever found in Europe. It is also the oldest known nodosaurid a family of ankylosaurs with wide, heavily armored bodies and have spiny sides and lack the tail clubs of their ankylosaurid cousins. The discovery of the dinosaur was announced today in the open-access scientific journal PLOS ONE. Based on two skeletons, the dinosaur was named Europelta carbonensis, which literally means Europe’s shield from the coal. The fossil site has produced multiple skeletons of animals in addition to Europelta. Dr. Luis Alcalá a co-author of the study said, “Spain represents the site of some of Europe’s most important dinosaur discoveries in recent years”.
The study was led by Dr. James Kirkland of the Geological Survey of Utah, Dr. Luis Alcalá of Fundación Conjunto Paleontológico de Teruel-Dinópolis/Museo Aragonés de Paleontología, and Dr. Mark Loewen, Research Associate at the Natural History Museum of Utah and Adjunct Assistant Professor in the Department of Geology and Geophysics at the University of Utah. Additional collaborative authors include Eduardo Espílez and Luis Mampel (Fundación Conjunto Paleontológico de Teruel-Dinópolis/Museo Aragonés de Paleontología) and Jelle Wiersma (Natural History Museum of Utah and Dept. of Geology and Geophysics, University of Utah).
Comparisons were made between the new specimens and ankylosaurs previously reported from North America Europe and other parts of the world. Dr. Mark Loewen, a co-author said, “these skeletons provide ample evidence to propose the hypothesis that all the known European nodosaurids belong to a distinct group, the Struthiosaurine, separate from North America’s nodosaurids based on distinctive features in their shoulders, hips, and legs”. Another group of ankylosaurs, the polacanthids (with distinct triangular heads and sharp plates running down the sides of their tails) predated the nodosaurids in both North America and Europe in the Late Jurassic and Early Cretaceous until their extinction about 120 million years ago. Immediately after this extinction, the first nodosaurids appear on both continents. This dramatic turnover does happen at the boundary of a geological time interval, but happened near the middle of the Aptian Age well before the end of the Early Cretaceous. The cause for this replacement is unknown, but for these low browsing plant-eaters the rapid diversification and rise to dominance of flowering plants at this time may have been a factor. Furthermore, CO2 levels, temperatures and sealevels were increasing to record highs at this time. The discovery of Europelta and the recognition of the struthiosaurines lend support to the theory that, as the continents flooded, Europe became isolated from North America following the initial appearance of the Nodosauridae. The study’s lead author Dr. James Kirkland said: “the diversification of nodosaurids separately on North America and Europe appears to correlate with rising sealevels flooding most of Europe to form an archipelago, isolating these dinosaurs even though the Atlantic Ocean had not fully opened as yet”.