Жоғалған динозаврлар туысы - Дысалотозавр

Extinct genus of dinosaurs

Dysalotosaurus ("uncatchable lizard") is a genus of herbivorous iguanodontian dinosaur. It was a dryosaurid iguanodontian, and its fossils have been found in late Kimmeridgian age rocks (Late Jurassic) of the Tendaguru Formation of Lindi Region in Tanzania. The type and only species of the genus is D. lettowvorbecki. This species was named by Hans Virchow in 1919 in honor of the Imperial German Army Officer, Paul von Lettow Vorbeck.

Thousands of Dysalotosaurus bones and bone fragments have been recovered from the Tendaguru Formation in Tanzania, Africa since 1909; It has been suggested that all of these specimens were part of a herd that was killed in a mass death event. as opposed to Josef Felix Pompeckj (1920), who is often incorrectly cited as naming the genus. In 2016, Gregory S. Paul estimated Dysalotosaurus' length at , and its weight at .

Various specimens of Dysalotosaurus are known, all representing animals that were not yet sexually mature at the time of their deaths. Ontogenetic studies demonstrate typical aging trends, such as a lengthening of the snout and relative shrinking of the orbit. Differences in dentition as the animals aged also suggest a change from an omnivorous diet early in life to fully herbivorous feeding habits as an adult.

Dysalotosaurus was a precocial dinosaur, which experienced sexual maturity at ten years, had an indeterminate growth pattern, and maximum growth rates comparable to a large kangaroo.

In 2011 paleontologists Florian Witzmann and Oliver Hampe from the Museum für Naturkunde and colleagues discovered that deformations of some Dysalotosaurus bones were likely caused by a viral infection similar to Paget's disease of bone. This is the oldest evidence of viral infection known to science. The discovery of a hemivertebra (spinal malformation) in another specimen likely caused scoliosis and other pathologic effects on the animal during its life. This malformation occurs in almost every vertebrate clade, though this is the first known evidence of the condition in dinosaurs.

Contemporary dinosaurs were Kentrosaurus, various sauropods including Giraffatitan and Dicraeosaurus, and large theropods including Megalosaurus and Ceratosaurus. Pterosaurs are also common in the Tendaguru Formation, as well as mammaliaformes (ancestral to mammals). During the Jurassic, Tendaguru was part of the semi arid coastline of Gondwana. Dysalotosaurus fossils were discovered in strata that were deposited in structures characteristic of tidal flats and lagoons.