Open Paleo

Cedarpelta

Carpenter et al., 2001 SEE-dar-PEL-tuh

Named for the Cedar Mountain Formation of Utah where the fossils were found, combined with Greek 'pelta' meaning 'shield', referring to its ankylosaurid armor.

121.4–100.5 million years ago Aptian–Albian, Early Cretaceous
Early Cretaceous stages

Cedarpelta is an extinct genus of basal ankylosaurid dinosaur from Utah that lived during the Early Cretaceous period in what is now the Mussentuchit Member of the Cedar Mountain Formation. The type and only species, Cedarpelta bilbeyhallorum, is known from multiple specimens including partial skulls and postcranial material. It was named in 2001 by Kenneth Carpenter, James Kirkland, Don Burge, and John Bird. Cedarpelta has an estimated length of 7 meters (23 feet) and weight of 5 tonnes (11,023 lbs). The skull of Cedarpelta lacks extensive cranial ornamentation and is one of the only known ankylosaurs with individual skull bones that are not completely fused together.

Diagnosis

  1. Paired premaxillae parallel-sided, not diverging posterolaterally as in other ankylosaurids; six alveoli in premaxilla
  2. Occipital condyle on a long neck projecting horizontally, not obliquely downward as in all other known ankylosaurids and nodosaurids
  3. Pterygoids anteroposteriorly elongated and vaulted; well-developed trochlear-like process along lateral edge of pterygoid
  4. Basitubera as a very large, ventral-projecting wedge (unpaired, unlike paired condition in all other ankylosaurs)
  5. Large oval process for adductor tendon on medial side of coronoid process of surangular
  6. Ischium with large knob on medial side near pubic peduncle

Species

Cedarpelta bilbeyhallorum Carpenter et al., 2001

Type species

Named for Sue Ann Bilbey and Evan Hall, who discovered the remains of Cedarpelta.

Holotype
CEUM 12360 , College of Eastern Utah Prehistoric Museum
Material
Partial skull missing the snout and lower jaws; possible rear portion of parietal
Horizon
upper Ruby Ranch Member, Cedar Mountain Formation, Aptian–Albian, Early Cretaceous , 121.4–100.5 million years ago
Locality
CEM site, Utah locality Em419v, near the Price River, Utah, United States

Synonyms

  • Bilbeyhallorum nomen nudum

    Informal genus name originally applied to the specimen; the name persists as the species epithet of Cedarpelta bilbeyhallorum.

References

  1. Kirkland, J. I.; Suarez, M.; Suarez, C.; Hunt-Foster, R. (2016). The Lower Cretaceous in east-central Utah — the Cedar Mountain Formation and its bounding strata. Geology of the Intermountain West 3: 101-228. Utah Geological Association. doi:10.31711/giw.v3.pp101-228

    Gives the holotype skull as from "the KEM site (Utah Em419v) in the upper Ruby Ranch Member".

    kirkland2016a
  2. Carpenter, K.; Kirkland, J. I.; Burge, D. L.; Bird, J. (2001). Disarticulated skull of a new primitive ankylosaurid from the Lower Cretaceous of eastern Utah. The Armored Dinosaurs 211-238. Indiana University Press, Bloomington. carpenter2001a
  3. Jones, B. (2026). The Princeton Encyclopedia of Dinosaurs: Ornithischians. Princeton University Press.

    Source of the hip height estimate, and the appearance features.

    jones2026a