Open Paleo

Alocodon

Thulborn, 1973 a-LOK-o-don Nomen dubium

From Greek 'alotrou' (a furrow) and 'odous' (tooth); meaning 'furrow tooth', alluding to the ribs and furrows ornamenting the lingual surfaces of the cheek crowns.

165.3–154.8 million years ago Callovian–Oxfordian, Middle Jurassic–Late Jurassic
Middle Jurassic and Late Jurassic stages

Alocodon is a genus of ornithischian dinosaur known from multiple teeth from the Middle or Late Jurassic Cabaços Formation of Portugal, and also the Forest Marble and Chipping Norton Formations of England. A single species is known, A. kuehnei.

Under dispute

Alocodon is a nomen dubium based on isolated teeth from the Middle to Late Jurassic of Portugal (Weishampel, 1990). Thulborn (1973) described it as an ornithopod in Hypsilophodontidae, then referred it to the now-abandoned Fabrosauridae; its affinities within Ornithischia cannot be demonstrated from the teeth.

Species

Alocodon kuehnei Thulborn, 1973 Nomen dubium

Type species

Honors Professor W. G. Kühne, whose work in Portugal in the 1960s yielded the Pedrógão microvertebrate fauna from which the type teeth came.

Holotype
IPFUB P X 2 , Museu Geológico do Instituto Geológico e Mineiro
Material
A single cheek-tooth crown from the Upper Callovian marls.
Notes
A single premaxillary tooth crown, IPFUB P X 1, is the designated paratype. Originally held at the Lehrstuhl für Paläontologie of the Free University, Berlin, and marked with the acronym IPFUB; the material is now in the Museu Geológico, Lisbon.
Horizon
Cabaços Formation, Callovian–Oxfordian, Middle Jurassic–Late Jurassic , 165.3–154.8 million years ago
Locality
Leiria, Portugal Thulborn (1973) writes that "The Pedrógão horizon is probably of Callovian age", and Mateus and Milàn (2009) give it as Oxfordian, after Azerêdo and colleagues (2002).

References

  1. Thulborn, R. A. (1973). Teeth of ornithischian dinosaurs from the Upper Jurassic of Portugal, with description of a hypsilophodontid (Phyllodon henkeli gen. et sp. nov.) from the Guimarota lignite. Memórias dos Serviços Geológicos de Portugal 22: 89-134.

    Originally placed Alocodon in Hypsilophodontidae; a 1974 postscript revised it into Fabrosauridae.

    thulborn1973a
  2. Jones, B. (2026). The Princeton Encyclopedia of Dinosaurs: Ornithischians. Princeton University Press.

    Treats Alocodon as a dubious genus of uncertain ornithopod affinity.

    jones2026a
  3. Mateus, O.; Milàn, J. (2009). A diverse Upper Jurassic dinosaur ichnofauna from central-west Portugal. Lethaia 43: 245-257. doi:10.1111/j.1502-3931.2009.00190.x

    Records the type material as held by the Museu Geológico, formerly under the acronym IPFUB.

    mateus2009b
  4. Weishampel, D. B.; Witmer, L. M. (1990). Lesothosaurus, Pisanosaurus, and Technosaurus. The Dinosauria (Weishampel, D. B.; Dodson, P.; Osmólska, H., eds.) 416-425. University of California Press, Berkeley.

    Calls Alocodon kuehnei a nomen dubium.

    weishampel1990a
  5. Azerêdo, A. C.; Wright, V. P.; Ramalho, M. M. (2002). The Middle–Late Jurassic forced regression and disconformity in central Portugal: eustatic, tectonic and climatic effects on a carbonate ramp system. Sedimentology 49(6): 1339-1370. doi:10.1046/j.1365-3091.2002.00501.x

    The source of the Oxfordian age Mateus and Milàn (2009) give the Pedrógão horizon.

    azerêdo2002a