Cedarpelta ‭(‬Cedar shield‭ ‬-‭ ‬after the Cedar Mountain Formation‭)‬

Short Info

Cedarpelta ‭(‬Cedar shield‭ ‬-‭ ‬after the Cedar Mountain Formation‭)‬

Phonetic : See-dar-pel-tah.

Named By : K.‭ ‬Carpenter,‭ ‬J.‭ ‬I.‭ ‬Kirkland,‭ ‬D.‭ ‬Birge‭ & ‬J.‭ ‬Bird‭ ‬-‭ ‬2001

Diet : Herbivore

Size : Estimated 60 cm long

Type of Dinosaur : Armoured Dinosaur

Type Species : C.‭ ‬bilbeyhallorum‭ (‬type‭)

Found in : USA,‭ ‬Utah‭ ‬-‭ ‬Cedar Mountain Formation,‭ ‬Mussentuchit Member

When it Lived : Early Cretaceous, 142-127 million years ago

Cedarpelta is an extinct species belonging to herbivores. ankylosaurid basal ankylosaurs which was discovered in the Lower Cretaceous of North America. The skull is devoid of extensive cranial ornamentation, a characteristic that is believed to be ankylosaurs’ plesiomorphism.


Cedarpelta price 1
Jens Lallensack, CC BY-SA 4.0, via Wikimedia Commons


In the year 1990, Sue Ann Bilbey and Evan Hall discovered a quarry that contained bones of ankylosaurs close to the Price River in Carbon County, Utah. In 1998, the finding was published in the scientific research literature. It was in the year 2001 that the of species Cedarpelta bilbeyhallorum was identified and was described by Kenneth Carpenter, James Kirkland, Donald Burge and John Bird. The scientific name is “Bilbey and Hall’s Cedar (Mountain) shield,” with the genus being named after the Cedar Mountain Formation and the plates of the animal’s armor which are derived taken from the Greek”pelte, “small shield” — and the particular name honoring Sue Ann Bilbey and Evan Hall as the two individuals who discovered the type locale.

Cedarpelta is recognized from the remains discovered in CEM and Price River II quarries. CEM as well as the Price River II quarries (PR-2) in the eastern region of Utah The locations were originally believed to be in the Ruby Ranch Member of the Cedar Mountain Formation However, they have been relegated to the bottom of the Mussentuchit Member, dating to between 116 and 109 million years old (approximately the Aptian-Albian boundary).

Cedarpelta was an extremely large ankylosaurian. In the year 2010, Gregory S. Paul declared a body size of 7 meters and an estimated weight of 5 tonnes. Kenneth Carpenter estimated it smaller at 5 meters. Thomas Holtz gave a higher estimation of 9 meters, which suggested it was a rival to Ankylosaurus.

Carpenter et al. (2001) identified a number of distinct characteristics of Cedarpelta. The praemaxilla’s body, also known as the front snout bone, is small on the front side of it’s nasal branch. The sides that are outside of both praemaxillae lie more parallel to the snouts in later types that are extremely diverging towards the back. A cutting point of bone inside the beak on top is confined only to the back of the praemaxilla. Each praemaxilla is equipped with the capacity of six (conical) teeth. The quadrate, and along with it, the entire rear of the skull is incline towards the front. The quadrate’s head is not joined to the paroccipital process, in contrast to what is seen in Shamosaurus. The condyle’s neck is long and sticks out in the rear, as with nodosaurids. However, it is not obliquely below like in the typical ankylosaurids. The tubera basilaria that joins processes in the lower part of the rear braincase, creates a massive wedge that is directed towards below. The pterygoid is extended from front to rear, and features a saddle-shaped procedure at its outer edges, that is oriented towards the side and behind. The coronoid region of the lower jaw’s back is an oval-shaped process on the interior. Straight ischiums feature an elongated boss on the interior, near the pedicle of pubic.

Cedarpelta displays a mix of basic (“primitive”) as well as derivative characteristics. Premaxillary teeth constitutes a pleniomorphic feature since it comes from Ornithischia that was earlier. However, the closure of the opening that runs along one side of skull that is behind the orbit, referred to as the temporal fenestra lateral to the orbit is an advanced related (apomorphic) characteristic that is only found within ankylosaurid ankylosaurians.

Two skulls are identified as well as the length of the skull for Cedarpelta is thought to be approximately 60 cm (24 inches). The one of Cedarpelta skulls was discovered disarticulated for the first time in an ankylosaur skull. This gives paleontologists the unique chance to study the bones individually rather than being restricted to an ossified part. The skull is quite extended and does not have an extremely appending beak. Of the conical premaxillary teeth the first one is the biggest. The maxilla has 18 teeth. Eye sockets are enclosed with the lacrimal. It is one supraorbital, and an enormous postorbital, which excludes the jugal and prefrontal of to the orbital margin. The postcranial skeleton has been described in 2001, however, it was not discussed in any depth.

The skulls, although the large size and are therefore not juvenile animals don’t show an identifiable pattern of caputegulae fused, skull tiles. This led Carpenter to suggest an alternative theory of the formation of ankylosaur skull osteoderm. In the past, it was believed that these armour plates were either created through direct skin ossification, resulting in distinct scutes that later became fused with the skull (the more well-known theory) or through the response of skull bone with the pattern of the scales that were overlying them. The absence of a distinct pattern in Cedarpelta suggests the Carpenter it was possible that the process of ossification process took place within an intermediate layer between the skull’s scales as well as the roof He speculated that it could be the periosteum.

Source: Wikipedia