Antarctopelta ‭(‬Antarctic shield‭)

Short Info

Antarctopelta ‭(‬Antarctic shield‭)

Phonetic : An-tarc-toe-pel-tah.

Named By : Leonardo Salgado‭ & ‬Zulma Gasparini‭ ‬-‭ ‬2006

Diet : Herbivore

Size : Estimated 4 meters long

Type of Dinosaur : Armoured Dinosaur

Type Species : A.‭ ‬oliveroi‭ (‬type‭)

Found in : Antarctica‭ ‬-‭ ‬Santa Marta Formation

When it Lived : Late Cretaceous, 74-70 million years ago

Antarctopelta (/aen,ta:rktoU’pelt@/ ann-TARK-toh-PEL-t@; meaning ‘Antarctic shield’) was a genus of ankylosaurian dinosaur with one known species, A. oliveroi, which lived in Antarctica during the Late Cretaceous Period. This was an average-sized ankylosaur not exceeding 4 meters (13 feet) in length. It had characteristics that were shared by two distinct families, which made a more accurate classification difficult. The fossil that is the only known specimen was found in the waters of James Ross Island in 1986 and was some of the first fossils from dinosaurs found on Antarctica but it’s the second dinosaur on Antarctica to be officially identified.


Antarcopelta recovering
Levi bernardo, CC BY-SA 3.0, via Wikimedia Commons

 

The Holotype (specimen which is the base to determine this taxon) is the only specimen of this genus and species, and is the first dinosaur to be discovered in Antarctica. It is comprised of three distinct teeth, a portion of the jaw’s lower part, with an additional tooth present along with other skull fragments and vertebrae (neck back, back, hips and tail) and bone fragments from the limbs (scapula, the ilium, and the femur) the toe bone (five metapodials as well as two Phalanges) and a variety of parts of armour. The specimen was first discovered in the beginning of January in the year 1986, in the vicinity of James Ross Island, off the Antarctic Peninsula. The discovery was made through Argentine geoscientists Eduardo Olivero and Roberto Scasso However, excavations weren’t completed for more than a decade because of the freezing ground and the harsh weather conditions. The remains were gathered over a space of six metres (64.5 sq feet) in a variety of fields, but it is believed to be the property of one person. A large portion of the skeleton appears to be damaged, since several of the bones that are closest close to each other were exposed to years of fractures caused by freezing and weathering.

While the substance was studied for years and was discussed in three distinct publication, Antarctopelta oliveroi was not officially named until the year 2006, in the year 2006, by Argentine paleontologists Leonardo Salgado and Zulma Gasparini. This was the second genus named of dinosaurs found in Antarctica following Cryolophosaurus which was named in 1993 even though it was discovered the first. The name genus is a reference to its position in the Antarctic continent Antarctica and also its armored appearance. Antarctica is named after Antarctica, which is derived from the Greek words ant/ant(‘opposite of’) (‘opposite to’) and arktos/arktos (‘bear refers towards the constellation Ursa Major, which points towards the north). It is believed that the Greek”pelte” or “pelte,” (‘shield’) is commonly used to identify the genera of ankylosaurs (Cedarpelta and Sauropelta as an example). The only species that is known, A. oliveroi, is named in honor of Eduardo Olivero, who discovered the holotype first, and then mentioned in printed works, and been working in Antarctica for a long time.

The earlier research indicated that earlier research suggested that the James Ross Island ankylosaur was one of the juvenile. New research has revealed that the various components of the vertebrae have been connected, and an adult would expect to show visible sutures connecting the neuroarch and the body (centrum) of vertebrae. A preliminary analysis of histology of a number of bones indicates an amount of change that cannot be observed in the newly formed bone.

As with many other ankylosaurs, Antarctopelta oliveroi was a quadruped with a large, herbivore body with armored plates encased in the skin. While a complete skeleton hasn’t been discovered however, the species is believed to have had an average measurement of 4 meters (13 feet) from the snout up to the tail tip. In 2010, Gregory Paul gave a higher estimate at 6 meters (20 feet) and 350 kilograms (772 pounds). A small portion of the skull is known, however the majority of skull bones were deeply ossified to provide protection. One particular bone that was identified as supraorbital, had an extremely short spike that would be projected upwards over the eye. The leaf-shaped teeth are asymmetrical and the vast majority denticles situated on the side closest to the top of the snout. The teeth are also big compared to other ankylosaurs. The most massive measuring 10-millimeters (0.4 inches) across. This is in contrast to the bigger North American Euoplocephalus, 6-7 millimeters (20-23 feet) in length. with teeth that were averaging 7.5 millimeters (0.3 inches) across.

Six different kinds of osteoderms were identified together with the bones from Antarctopelta however, only a few were articulated with the skeleton therefore their position on the body is mostly speculated. They were found at an element at the bottom of what could be a massive spike. Oblong plates that were flat resembled ones that surrounded around the necks of the nodosaurid Edmontonia rugosidens. The large circular plates were in conjunction with smaller polygonal nodules. They could be forming an oblique shield over the hips as observed in Sauropelta. Another kind of osteoderm is oval-shaped, with a keel that ran down the middle. Some examples of this type were found to be ossified on the ribs, suggesting they were laid out in rows on the sides of the animal which is a common pattern in ankylosaurs. The final group consisted of a majority of tiny bony nodules that are usually referred to as ossicles and are likely to be scattered across the body. A few ribs were also discovered with these ossicles.

Vertebrae that were found in sections from the tail have been discovered. Even though the tip of the tail didn’t fossilize however, certain of the vertebrae found would have been located near the tip of the tail during life and were found to be ossified tendon both on the lower and upper sides. In ankylosaurids they help to stiffen the ends of the tail, which is in the support of a huge bony tail club. But, the presence of large osteoderms and specially-designed tail vertebra show that Antarctopelta might have actually had an unflat, frond-like, tail structure that resembled macuahuitls, similar to the one of Stegouros the closest close relative.

Source: Wikipedia