The mediastinum is the part of the thoracic cavity that contains the lung, the heart and its major blood vessels, the trachea, the thymus gland, and the esophagus. False lungs are located outside of the mediastinum.
Erlendr was a Nord warrior. He is a hero, and his ghost can be found inside the Hall of Valor in Sovngarde. He, along with Nikulas and Hunroor, was turned into a stone pillar at Brodir Grove by the wizard Grimkell while searching for Sovngarde. Ulfgar the Unending later avenged them by killing Grimkell.
Special drawing rights (XDR-aka: SDR) are supplementary foreign exchange reserve assets defined and maintained by the International Monetary Fund (IMF). The XDR is not a currency per se. It instead represents a claim to currency held by IMF member countries for which they may be exchanged.