Open Paleo

Adelolophus

Gates et al., 2014 ah-DELL-o-LOW-fuhs

From Greek 'adelos' meaning 'unknown' or 'obscure' and 'lophos' meaning 'crest'; meaning 'unknown crest'

83.6–72.2 million years ago Campanian, Late Cretaceous
Late Cretaceous stages

Adelolophus is a genus of lambeosaurine dinosaur (a crested "duck-bill") from Upper Cretaceous rocks in the U.S. state of Utah. The type and only known species is A. hutchisoni; the type specimen consists only of a broken maxilla. It constitutes the oldest known lambeosaur remains from North America, as well as the only known lambeosaur species from the Wahweap Formation, of which it pertains to the Upper Member. Among its relatives, it seems to be particularly similar to Parasaurolophus, rather than animals like Lambeosaurus; phylogenetic analysis confirms this, finding it in Parasaurolophini (tube-headed lambeosaurs). It would have lived in a wet environment, bordering on the sea but with a more arid season during some times of the year. This environment would have been shared with a diverse variety of fish and turtles, as well as other dinosaurs like ceratopsids and tyrannosaurids.

Diagnosis

  1. Medial wall of the maxillary anterior process taller than in other lambeosaurines
  2. Medial wall of the maxillary posterior process taller than in all known lambeosaurines, extending to the dorsal process and sloping posteroventrally, placing the palatine process well above the position found in other lambeosaurines
  3. Thickened ridge extending posterodorsally from the ventral articulation of the jugal with the maxilla to the palatine process

Species

Adelolophus hutchisoni Gates et al., 2014

Type species

Named for John Howard Hutchison, who collected the type specimen from the Wahweap Formation of Utah in 1999.

Holotype
UCMP 152028 , University of California Museum of Paleontology
Material
Partial maxilla (?Upper Member).
Horizon
lower Coyote Point Member, Wahweap Formation, Campanian, Late Cretaceous , 83.6–72.2 million years ago
Locality
UCMP locality V98173, Utah, United States

References

  1. Gates, T. A.; Jinnah, Z.; Levitt, C.; Getty, M. A. (2014). New hadrosaurid (Dinosauria, Ornithopoda) specimens from the lower-middle Campanian Wahweap Formation of southern Utah. Hadrosaurs 156-173. Indiana University Press. gates2014b
  2. Holroyd, P. A.; Hutchison, J. H. (2016). Fauna and setting of the Adelolophus hutchisoni type locality in the Upper Cretaceous (Campanian) Wahweap Formation of Utah. PaleoBios 33.

    Fixes the type locality as UCMP V98173 (= USGS D815) and places it low in the upper member.

    holroyd2016a
  3. Beveridge, T. L.; Roberts, E. M.; Ramezani, J.; Titus, A. L.; Eaton, J. G.; Irmis, R. B.; Sertich, J. J. W. (2022). Refined geochronology and revised stratigraphic nomenclature of the Upper Cretaceous Wahweap Formation, Utah, U.S.A. and the age of early Campanian vertebrates from southern Laramidia. Palaeogeography, Palaeoclimatology, Palaeoecology 591: 110876. Elsevier BV. doi:10.1016/j.palaeo.2022.110876

    Formalizes the Wahweap's informal upper member as the Coyote Point Member.

    beveridge2022a
  4. Jones, B. (2026). The Princeton Encyclopedia of Dinosaurs: Ornithischians. Princeton University Press.

    Source of the body length estimate.

    jones2026a