vertebrae of the holotype may be a gastrolith, based on its polished appearance. In 2007 the Colombian paleontologists Leslie Noè and Marcela Gómez-Pérez expressed doubt that the additional elements belonged to the type specimen, or even to Elasmosaurus, due to lack of evidence. They explained that elements missing from the holotype may have been lost to weathering or simply not collected, and that parts may have been lost or damaged during transportation or preparation. Gastroliths may also not have been recognized as such during collection, since such stones were not reported from a plesiosaur until ten years after. In 2017 Sachs and Joachim Ladwig suggested that a fragmentary elasmosaurid skeleton from the upper Campanian of Kronsmoor in Schleswig-Holstein, Germany, and housed in the Naturkunde-Museum Bielefeld, may have belonged to Elasmosaurus. Additional parts of the same skeleton are housed at the Institute for Geology of the University of Hamburg, as well as in private collections. Combined, the specimen consists of neck, back and tail vertebrae, phalanges, a tooth, limb elements, 110 gastroliths, and unidentifiable fragments. Description Though the only known specimen of Elasmosaurus (holotype specimen ANSP10081) is fragmentary and missing many elements, related elasmosaurids show it would have had a compact, streamlined body, long, paddle-like limbs, a short tail, a proportionately small head, and an extremely long neck. The neck of Elasmosaurus is estimated at in length; thus, Elasmosaurus and its relative Albertonectes were some of the longest-necked animals ever to have lived, with the largest number of neck vertebrae of any known vertebrate animals. In spite of their many neck vertebrae, the necks of elasmosaurids were less than half as long as those of the longest-necked sauropod dinosaurs. Initially, in his 1869 description of Elasmosaurus, Cope estimated the length of the animal by summing up vertebral lengths and estimations of missing parts, resulting in a total length of ; he believed that the living animal would have been slightly larger due to cartilage present between the vertebral bodies, and was estimated at roughly . However, in 1952, the American paleontologist Samuel Welles estimated the body length to have been . An Elasmosaurus of this length would have measured in body mass. Like other elasmosaurids, Elasmosaurus would have had a slender, triangular skull. The snout was rounded and almost formed a semi-circle when viewed from above, and the premaxillae (which form the front of the upper jaw) bore a low keel