Abditosaurus

Abditosaurus (meaning "forgotten lizard") is an extinct genus of titanosaurian sauropod dinosaur from the Late Cretaceous (Maastrichtian) Conques Formation (Tremp Group) of Catalonia, Spain. The genus contains a single species, Abditosaurus kuehnei, known from a partial specimen representing the most complete titanosaur skeleton found in Europe. Phylogenetic analyses recover it within a clade of South American and African saltasaurines, distinct from other insular dwarf sauropods from the European archipelago. Abditosaurus inhabited the Ibero-Armorican Island, a prehistoric island made up of what is now Spain, Portugal, and southern France, and would have been the largest titanosaur species in its environment.

==History of study== While prospecting for fossil mammals in 1954, German paleontologist Walter Georg Kühne on 25 September discovered the remains of a large titanosaur at the Orcau-1 locality of the Conques Formation of Catalonia, Spain. It was the first major sauropod find in Spain. During the initial two weeks of excavation Kühne managed to identify around ten bones, some of which were packaged and sent to the Instituto Lucas Mallada (ILM) in Madrid, while others remained at the site (jacketed for protection). Returning the following year, Kühne, alongside locals and researchers of the ILM, managed to identify ten more bones in addition to most of those left at the site. Like in 1954, some of the bones were transported to Madrid while the remainder were left at the site. These initial discoveries consisted of fragments of the ilium, parts of the scapula, dorsal vertebrae, chevrons, a tibia, parts of the femurs and a complete humerus alongside undetermined bones. Although Kühne asked for additional excavations, funding had run out and work at the locality was stopped. In 1956, the fossil material recovered was assigned by Albert-Félix de Lapparent and Emiliano Aguirre to a new, but unnamed, species of the now dubious genus Hypselosaurus. It was not until 1984 and 1986 that additional expeditions to the area were conducted, helmed by Josep Vicenç Santafé of the Institut de Paleontologia de Sabadell, Barcelona, and assisted by researchers of the Institut d'Estudis Ilerdencs, Lleida. They identified a sternal plate and additional dorsal vertebrae. Another expedition was conducted from 2012 to 2014 by the Institut Català de Paleontologia, the University of Zaragoza and the Museu de la Conca Dellà. This expedition recovered elements left at the site by the 1955 and 1986 digs, with additional material of the limbs, tooth fragments, ribs and an articulated series of dorsal and cervical vertebrae. Subsequent research managed to discover some of the historical material. In 2017, part of the initial finds were described. This finding was shown in the 2017 documentary "''Europe's Last Giant".