an outcrop of the Khok Kruat Formation near the city of Khon Kaen. The specimen (SM-KK 14) consists of cervical (neck) and dorsal (back) vertebrae, a high neural spine (upwards-extending process from top of vertebra), pelvis (hip) fragments, a possible metacarpal (long bone of the hand), and a chevron from the tail. The cervical vertebrae and pelvic region resemble those of the European spinosaur Baryonyx walkeri, and the neural spine is elongated, similarly to those of other spinosaurids. A Siamosaurus tooth found nearby indicates the skeleton may belong to this genus, though this could also represent evidence of scavenging. The skeleton, as well as two well-preserved teeth—SM2016-1-147 and SM2016-1-165, also attributed to Siamosaurus—are currently stored in the vertebrate fossil collection of the Sirindhorn Museum, Kalasin Province. In 2019, a series of spinosaurid caudal (tail) vertebrae possibly belonging to S. suteethorni were recovered from the Sao Khua Formation, and described in a dissertation by Samathi. The fossils (SM-PW9B-11 to 17, SM-PW9B, SM-PW9A-unnumbered, SM-PW9-unnumbered, and SM 2017-1-176) were designated by Samathi as "Phuwiang spinosaurid B", and bear similarities to the possible spinosaurid Camarillasaurus and a Baryonyx specimen discovered in Portugal. Description In 2004, American dinosaur researcher Don Lessem estimated Siamosaurus at long. In 2005, British author Sussana Davidson and colleagues gave a lower estimate of in length and weighing . In a 2016 popular book, Spanish palaeontologists Rubén Molina-Pérez and Asier Larramendi estimated it at approximately long, tall at the hips, and weighing . However, reliable calculations on the weight and body size of fragmentary dinosaurs like Siamosaurus are hindered by the lack of good material, such as a skull or postcranial skeleton, and thus estimates are only tentative. "Phuwiang spinosaurid B" was calculated as approximately long by Samathi in 2019. As a spinosaurid, Siamosaurus would have had low, narrow, and elongated jaws; well-built forelimbs; relatively short hindlimbs; and elongated neural spines on the vertebrae forming a sail on its back. Type specimens Fossil theropod teeth are typically identified by attributes such as the proportions, size, and curvature of the crown, as well as the presence and/or shape of the denticles (serrations). The holotype of S. suteethorni (specimen DMR TF 2043a) is in total length, with the crown being long, and wide at its base. It is among the larger teeth discovered by Buffetaut and Ingavat. One much smaller specimen (DMR TF 2043b) measures in length. According to the authors, this dramatic