Open Paleo

Uteodon

McDonald, 2011

From 'Ute', the Native American people of the region around Dinosaur National Monument, and Greek 'odon' ('tooth'); meaning 'Ute tooth'.

154.8–149.2 million years ago Kimmeridgian, Late Jurassic
Late Jurassic stages

Uteodon is a genus of herbivorous iguanodontian dinosaur. It is a basal iguanodontian which lived during the late Jurassic period in what is now Uintah County, Utah. It is known from the middle of the Brushy Basin Member, Morrison Formation. The genus was named by Andrew T. McDonald in 2011 and the type species is U. aphanoecetes.

Under dispute

The validity of Uteodon is contested. McDonald (2011) erected the genus for the Dinosaur National Monument skeleton that Carpenter and Wilson (2008) had named Camptosaurus aphanoecetes, diagnosing it in part on an occipital condyle projecting farther ventrally than the basal tubera. Carpenter and Lamanna (2015) reassigned the braincase carrying that character to Dryosaurus and concluded the genus has no diagnosis separating it from Camptosaurus, returning the species to Camptosaurus aphanoecetes. Sánchez-Fenollosa and colleagues (2023) recover the three species as a clade and follow that synonymy, whereas Fonseca and colleagues (2024) retain Uteodon as a separate genus until Camptosaurus dispar is more fully described, and Poole (2022) treats it as its own genus; it is kept valid here. Its position is separately unsettled: McDonald (2011) recovered it among the most basal Styracosterna, whereas Poole (2022) and Fonseca and colleagues (2024) recover it as a basal ankylopollexian outside Styracosterna. Poole (2022) went further and emended the definition of Ankylopollexia to name Uteodon aphanoecetes an internal specifier, which places it inside that clade by construction. It is placed at Ankylopollexia incertae sedis.

Diagnosis

  1. Scapula has an acromion process that is convex along its cranial margin
  2. Dorsal margin of the scapula is convex
  3. Dorsal margin of the ilium is convex and thickens mediolaterally towards the M. iliocaudalis platform
  4. Postacetabular process of the ilium tapers to a point with a break in slope along the dorsal margin
  5. Distal end of the ischium forms a cranially expanded boot
  6. Postzygapophyses of the axis extend well beyond the posterior face of the centrum
  7. Neural spine of the axis is laterally compressed above the postzygapophyses rather than expanded into a deep pocket
  8. Cervical vertebra 7 has a wedge-shaped centrum in lateral view
  9. Neural arches of the posterior cervical vertebrae are very tall
  10. Scapular blade is arched in profile with a steeply sloped distal end
  11. Deltopectoral crest of the humerus is a low, non-prominent triangle

Species

Uteodon aphanoecetes (Carpenter & Wilson, 2008)

Type species

First named as Camptosaurus aphanoecetes

From Greek 'aphanoe-' ('hidden') and '-cetes' ('to dwell'), for a specimen that had stood on public exhibit unrecognized for over 75 years.

Holotype
CM 11337 , Carnegie Museum of Natural History
Material
Partial articulated skeleton: 8 cervicals, 16 dorsals, 4 sacrals, 14 caudals, scapulae, left coracoid, humeri, forearm and manus, ilia, pubes, ischia, femora, tibiae, fibulae, ribs, ossified tendons.
Horizon
middle Brushy Basin Member, Morrison Formation, Kimmeridgian, Late Jurassic , 154.8–149.2 million years ago
Locality
East end of Carnegie Quarry, Dinosaur National Monument, Utah, United States Whitlock and colleagues (2025) date the Carnegie Quarry "ca. 150-151 Ma", which they label Tithonian; on the ICS chart v2024/12, whose Tithonian begins at 149.2 Ma, that is Kimmeridgian.

References

  1. McDonald, A. T. (2011). The taxonomy of species assigned to Camptosaurus (Dinosauria: Ornithopoda). Zootaxa 2783(1). Magnolia Press. doi:10.11646/zootaxa.2783.1.4

    Erects the genus for Camptosaurus aphanoecetes and recovers it among the most basal Styracosterna.

    mcdonald2011a
  2. Carpenter, K.; Wilson, Y. (2008). A new species of Camptosaurus (Ornithopoda: Dinosauria) from the Morrison Formation (Upper Jurassic) of Dinosaur National Monument, Utah, and a biomechanical analysis of its forelimb. Annals of Carnegie Museum 76(4): 227-263. Carnegie Museum of Natural History. doi:10.2992/0097-4463(2008)76[227:ANSOCO]2.0.CO;2

    Erects the species as Camptosaurus aphanoecetes on CM 11337; source of the holotype material and the original species diagnosis.

    carpenter2008a
  3. Carpenter, K.; Lamanna, M. C. (2015). The braincase assigned to the ornithopod dinosaur Uteodon McDonald, 2011, reassigned to Dryosaurus Marsh, 1894: implications for iguanodontian morphology and taxonomy. Annals of Carnegie Museum 83(2): 149-165. Carnegie Museum of Natural History. doi:10.2992/007.083.0201

    Refers the braincase bearing the genus's diagnostic character to Dryosaurus and treats Uteodon as a junior subjective synonym of Camptosaurus.

    carpenter2015a
  4. Poole, K. E. (2022). Phylogeny of iguanodontian dinosaurs and the evolution of quadrupedality. Palaeontologia Electronica 25(3): a30. doi:10.26879/702

    Recovers Uteodon as the most basal ankylopollexian and emends the definition of Ankylopollexia to name it an internal specifier.

    poole2022a
  5. Fonseca, A. O.; Reid, I. J.; Venner, A.; Duncan, R. J.; Garcia, M. S.; Müller, R. T. (2024). A comprehensive phylogenetic analysis on early ornithischian evolution. Journal of Systematic Palaeontology 22: 2346577. doi:10.1080/14772019.2024.2346577

    Declines the synonymy with Camptosaurus and recovers Uteodon as a basal ankylopollexian.

    fonseca2024a
  6. Sánchez-Fenollosa, S.; Verdú, F. J.; Cobos, A. (2023). The largest ornithopod (Dinosauria: Ornithischia) from the Upper Jurassic of Europe sheds light on the evolutionary history of basal ankylopollexians. Zoological Journal of the Linnean Society 199(4): 1013-1033. Oxford University Press (OUP). doi:10.1093/zoolinnean/zlad076

    Recovers Camptosaurus aphanoecetes in a clade with C. dispar and C. prestwichii and follows Carpenter and Lamanna in treating Uteodon as a subjective synonym of Camptosaurus.

    sánchez-fenollosa2023a
  7. Maidment, S. C. R.; Chapelle, K. E. J.; Bonsor, J. A.; Button, D.; Barrett, P. M. (2023). Osteology and relationships of Cumnoria prestwichii (Ornithischia: Ornithopoda) from the Late Jurassic of Oxfordshire, UK. Monographs of the Palaeontographical Society 176(664): 1-55. doi:10.1080/02693445.2022.2162669

    Uses Uteodon as a comparative taxon throughout the osteology of Cumnoria prestwichii.

    maidment2023a
  8. Bonsor, J. A.; Lockwood, J. A. F.; Leite, J. V.; Scott-Murray, A.; Maidment, S. C. R. (2023). The osteology of the holotype of the British iguanodontian dinosaur Mantellisaurus atherfieldensis. Monographs of the Palaeontographical Society 177(665): 1-63. doi:10.1080/02693445.2023.2234156

    Scores Uteodon aphanoecetes as a distinct terminal taxon in a redescription of the Mantellisaurus holotype.

    bonsor2023a
  9. Whitlock, J. A.; Garderes, J. P.; Gallina, P.; Lamanna, M. C. (2025). Athenar bermani, a new species of dicraeosaurid sauropod from Dinosaur National Monument, Utah, U.S.A. Palaeontologia Electronica. Coquina Press. doi:10.26879/1550

    Dates the Carnegie Quarry "ca. 150-151 Ma".

    whitlock2025a