Alamosaurus

Alamosaurus (/ˌæləmɵˈsɔrəs/; meaning "Ojo Alamo lizard") is a genus of titanosaurian sauropod dinosaurs, containing a single species, Alamosaurus sanjuanensis, from the late Cretaceous Period of what is now southern North America. It was a large quadrupedal herbivore. 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.[1] Its fossils have been recovered from a variety of geological formations spanning the Maastrichtian stage (late Edmontonian-Lancian land vertebrate ages) of the Late Cretaceous. 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.[

Naming
Contrary to popular assertions, this dinosaur is not named after the Alamo in San Antonio, Texas, or the battle that was fought there. The holotype, or original specimen, was discovered in New Mexico and, at the time of its naming, Alamosaurus had not yet been found in Texas. Instead, the name Alamosaurus comes from Ojo Alamo, the geologic formation in which it was found and which was, in turn, named after the nearby Ojo Alamo trading post (since this time there has been some debate as to whether to reclassify the Alamosaurus-bearing rocks as belonging to the Kirtland Formation or whether they should remain in the Ojo Alamo Formation). The term alamo itself is a Spanish word meaning "poplar" and is used for the local subspecies of cottonwood tree. The term saurus is derived from saura (σαυρα), Greek for "lizard" and is the most common suffix used in dinosaur names. There is one species (A. sanjuanensis), which is named after San Juan County, New Mexico, where the first remains were found. Both genus and species were named by Smithsonian paleontologist Charles W. Gilmore in 1922.[

Anatomy
The vertebrae from the middle part of its tail had elongated centra.[4] Alamosaurus had vertebral lateral fossae that resembled shallow depressions.[5] Fossae that similarly resemble shallow depressions are known from Saltasaurus, Malawisaurus, Aeolosaurus, and Gondwanatitan.[5] 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.[5]

Alamosaurus had more robust radii than Venenosaurus.[