Open Paleo

Lophorhothon

Langston, 1960 LOF-o-ROH-thon

From Greek 'lophos' meaning 'crested' and 'rhothon' meaning 'nose', giving the meaning 'crested nose', referring to the nasal crest of the holotype.

85.7–72.2 million years ago Santonian–Campanian, Late Cretaceous
Late Cretaceous stages

Lophorhothon is a genus of hadrosauroid dinosaur from the Late Cretaceous of Alabama, and possibly Georgia and North Carolina. It was the first dinosaur genus discovered in Alabama, in the United States.

Under dispute

Lophorhothon atopus was originally described as a basal hadrosaurine, inside Hadrosauridae (Langston, 1960), but later analyses place it within Hadrosauromorpha just outside Hadrosauridae, among the closest non-hadrosaurid relatives of the family (Gates and Lamb, 2021; Alarcón-Muñoz and colleagues, 2023).

Diagnosis

  1. Pyramidal nasal crest situated well forward of the orbits
  2. Nasal crest bearing two shallow, roughly concentric lateral depressions opening forward toward the nares
  3. Large, nearly diamond-shaped fronto-nasal fontanel bounded by the nasals in front and finger-like processes of the domed frontals behind
  4. Frontals strongly domed above the orbits
  5. Squamosals very widely separated medially, not meeting at the midline

Species

Lophorhothon atopus Langston, 1960

Type species

From Ancient Greek 'atopos' meaning 'uncommon' or 'strange', referring to the unusual features of this dinosaur.

Holotype
FMNH P 27383 , Field Museum of Natural History
Material
A disarticulated partial skull (nasals, frontals, lacrimals, maxilla, braincase) with 44 vertebrae, partial ischia, the left femur, and nearly complete lower legs and feet of a juvenile.
Horizon
lower Mooreville Chalk Formation, Santonian–Campanian, Late Cretaceous , 85.7–72.2 million years ago
Locality
Site 9, Moore Brothers' Farm, Alabama, United States

References

  1. Langston, W. (1960). The vertebrate fauna of the Selma Formation of Alabama. Part VI, The dinosaurs. Fieldiana: Geology Memoirs 3(5): 315-359. Chicago Natural History Museum. doi:10.5962/bhl.title.5344 langston1960a
  2. Gates, T. A.; Lamb, J. P. (2021). A redescription of Lophorhothon atopus (Ornithopoda: Dinosauria) from the Late Cretaceous of Alabama based on new material. Canadian Journal of Earth Sciences 58(9): 918-935. Canadian Science Publishing. doi:10.1139/cjes-2020-0173

    Prints a field-checked coordinate for site 9 and places the holotype 22 m above the Eutaw contact.

    gates2021a
  3. Paul, G. S. (2024). The Princeton Field Guide to Dinosaurs (3rd ed.). Princeton University Press.

    Source of the appearance features.

    paul2024a
  4. Alarcón-Muñoz, J.; Vargas, A. O.; Püschel, H. P.; Soto-Acuña, S.; Manríquez, L.; Leppe, M.; Kaluza, J.; Milla, V.; Gutstein, C. S.; Palma-Liberona, J.; Stinnesbeck, W.; Frey, E.; Pino, J. P.; Bajor, D.; Núñez, E.; Ortiz, H.; Rubilar-Rogers, D.; Cruzado-Caballero, P. (2023). Relict duck-billed dinosaurs survived into the last age of the dinosaurs in subantarctic Chile. Science Advances 9(24). American Association for the Advancement of Science (AAAS). doi:10.1126/sciadv.adg2456

    Recovered Lophorhothon among early-diverging hadrosauromorphs outside Hadrosauridae.

    alarcón-muñoz2023a
  5. Jones, B. (2026). The Princeton Encyclopedia of Dinosaurs: Ornithischians. Princeton University Press.

    Treats Lophorhothon as a non-hadrosaurid hadrosauromorph.

    jones2026a