The Last Pterosaurs： First Record from the Uppermost Maastrichtian of the Tremp Syncline （Northern Spain）

Pterosaur bones are for the first time reported from the Tremp Syncline （Spain） and the southern Pyrenees. They come from the Torrebilles-2 site （Isona, Lleida Province） in the upper Maastrichtian part of the Tremp Formation, which falls within the C29r magnetochron. Fragmentary long bones are referred to the Pterosauria based on their cortical thinness, micro-architecture, and histological features. They belong to very large to possibly giant individuals. The most complete specimen is possibly a partial right femur. The review of the Maastrichtian pterosaur record shows that only a few specimens can be referred to the C29r （which contains the K/Pg boundary）. The identification of fragmentary remains could improve our knowledge about the abundance and distribution of these flying sauropsids just before the end-Cretaceous mass extinction.