MEANING: Very spiky tail
PERIOD: Late Jurassic - Early Cretaceous
CONTINENT: Europe
Dacentrurus is a stegosaurian dinosaur from the Late Jurassic to Early Cretaceous, discovered in what is now England. Dacentrurus was one of the largest stegosaurs, with some specimens estimated to reach up to 9 m in length, and weighing around 5 t. Though finds of this animal have been limited and much of its appearance is uncertain, it was a heavily built quadrupedal herbivore with plates and spikes along its back.
Dacentrurus is from the Jurassic and Cretaceous. The Jurassic is a geologic period that spanned from the end of the Triassic, 201 million y ears ago, to the beginning of the Cretaceous, 145 million years ago. It is the middle period of the Mesozoic Era. The start of the Jurassic was marked by the major Triassic-Jurassic extinction event. The end, however, has no clear boundary with the Cretaceous. By the beginning of the Jurassic, Pangea had begun rifting into two landmasses: Laurasia and Gondwana, and the climate was warm with no ice caps. Life on land was dominated by dinosaurs, and the first birds appeared, evolving from a branch of theropods. The oceans were inhabited by marine reptiles, while pterosaurs were the dominant flying vertebrates.
The Cretaceous is a geological period that lasted from about 145 to 66 million years ago. It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of the entire Phanerozoic. The name is derived from the Latin creta, "chalk", which is abundant in the latter half of the period.
The Cretaceous was a period with a relatively warm climate, resulting in high eustatic sea levels that created numerous shallow inland seas. These oceans and seas were populated with now-extinct flora and fauna, while dinosaurs continued to dominate on land. The world was ice free, and forests extended to the poles. During this time, new groups of mammals and birds appeared. During the Early Cretaceous, flowering plants appeared and began to rapidly diversify, becoming the dominant group of plants across the Earth by the end of the Cretaceous, coincident with the decline and extinction of previously widespread gymnosperm groups.
The Cretaceous (along with the Mesozoic) ended with the Cretaceous–Paleogene extinction event, a large mass extinction in which many groups, including non-avian dinosaurs, pterosaurs, and large marine reptiles, died out. The end of the Cretaceous is defined by the abrupt Cretaceous–Paleogene boundary (K–Pg boundary), a geologic signature associated with the mass extinction that lies between the Mesozoic and Cenozoic Eras.
Dacentrurus is a stegosaurian. Stegosauria is a group of herbivorous ornithischian dinosaurs that lived mainly during the Jurassic period, though there are some members known from the early Cretaceous. Stegosaurian fossils have been found mostly in the Northern Hemisphere.
Stegosaurians were armored dinosaurs; together with the ankylosaurs, they make up a larger group known as the thyreophorans. An early evolutionary innovation was the development of spikes as defensive weapons. Over time, these developed into much larger plates and spikes as the species within the group grew to larger size. These plates usually tend to run in two rows down the back, and end as spikes, known as thagomizers, at the tip of the tail.