page_title: Alamosaurus
section_title: Description
hierarchical_section_title: Alamosaurus / Description
caption_attribution_description: English: Hypothetical restoration of Alamosaurus sanjuanensis, based on Scott Hartman's skeletal restoration [1] with speculative quills and hypothetical osteoderms' position and osteoderms' layout loosely based on this interpretation, which is based on the work of Vidal et. al., 2015 [2]. • Alamosaurus body proportion is based on Scott Hartman's rescontruction, used with permission [3] • Alamosaurus is known to have supported osteoderms. The number of these osteoderms that an individual Alamosaurus would have supported in life and their and position on the body is not currently known. It's thought that due to the rarity of titanosaur osteoderms that they would be quite sparse on the body. The position and layout of the osteoderms has been loosely based on this interpretation, which is based on the work of Vidal et. al., 2015. [4]
context_page_description: Alamosaurus is a genus of potentially opisthocoelicaudiine titanosaurian sauropod dinosaurs, containing a single ±known species, Alamosaurus sanjuanensis, from the late Cretaceous Period of what is now southern North America. Isolated vertebrae and limb bones indicate that it reached sizes comparable to Argentinosaurus and Puertasaurus, which would make it the largest dinosaur known from North America. Its fossils have been recovered from a variety of rock formations spanning the Maastrichtian age of the late Cretaceous period. Specimens of a juvenile Alamosaurus sanjuanensis have been recovered from only a few meters below the Cretaceous-Paleogene boundary in Texas, making it among the last surviving non-avian dinosaur species.
context_section_description: Alamosaurus was a gigantic quadrupedal herbivore with a long neck and tail and relatively long limbs. Its body was at least partly covered in bony armor. In 2012 Thomas Holtz gave a total length of 30 meters (98 ft) or more and an approximate weight of 72.5-80 tonnes (80-88 short tons) or more. Though most of the complete remains come from juvenile or small adult specimens, three fragmentary specimens, SMP VP−1625, SMP VP−1850 and SMP VP−2104, suggest that adult Alamosaurus could have grown to enormous sizes comparable to the largest known dinosaurs like Argentinosaurus, which has been estimated to weigh 73 metric tons (80 short tons).  Scott Hartman estimates Alamosaurus, based on a huge incomplete tibia that probably refers to it, being slightly shorter at 28–30 m (92–98 ft) and equal in weight to other massive titanosaurs such as Argentinosaurus and Puertasaurus. However, he says that at the moment, scientists do not know whether the massive tibia belongs to an Alamosaurus or a completely new species of sauropod. In 2019 Gregory S. Paul estimated the (SMP VP−1625) specimen at 27 tonnes (30 short tons), and he also mentioned a large partial anterior caudal vertebra which suggests an Alamosaurus specimen that is 15 percent dimensionally larger with similar mass to his Dreadnoughtus estimation of 31 tonnes (34 short tons). In 2020 Molina-Perez and Larramendi estimated the size of the largest individual at 26 meters (85.3 ft) and 38 tonnes (42 short tons). 
  Though no skull has ever been found, rod-shaped teeth have been found with Alamosaurus skeletons and probably belonged to this dinosaur. The vertebrae from the middle part of its tail had elongated centra. Alamosaurus had vertebral lateral fossae that resembled shallow depressions. Fossae that similarly resemble shallow depressions are known from Saltasaurus, Malawisaurus, Aeolosaurus, and Gondwanatitan. Venenosaurus also had depression-like fossae, but its "depressions" penetrated deeper into the vertebrae, were divided into two chambers, and extend farther into the vertebral columns. Alamosaurus had more robust radii than Venenosaurus.
caption: Hypothetical restoration
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