Open Paleo

Cryptosaurus

Seeley, 1875 KRIP-to-SOR-us Nomen dubium

From Greek 'kryptos' (hidden) and 'sauros' (lizard); meaning 'hidden lizard', in reference to the rarity of the find.

161.5–154.8 million years ago Oxfordian, Late Jurassic
Late Jurassic stages

Cryptosaurus is a dubious genus of dinosaur known from a partial femur from the Late Jurassic of England. The sole species is Cryptosaurus eumerus.

Species

Cryptosaurus eumerus Seeley, 1875 Nomen dubium

Type species

From Greek 'eu' (well) and 'merus' (thigh); meaning 'well-formed thigh', in reference to the stout build of the holotype femur.

Holotype
CAMSM J.46882 , Sedgwick Museum, University of Cambridge
Material
A single right femur, approximately 31 cm long, with a slight antero-posterior flexure in the lower third of the shaft; articular ends lack epiphyses.
Horizon
Ampthill Clay Formation, Oxfordian, Late Jurassic , 161.5–154.8 million years ago
Locality
Great Gransden, Cambridgeshire, United Kingdom

Synonyms

  • Cryptodraco eumerus junior objective

    Lydekker (1889) proposed Cryptodraco as a replacement name for Cryptosaurus, believing the latter to be preoccupied by an earlier reptile name. The perceived senior homonym was actually a misspelling of Cystosaurus (Geoffroy Saint-Hilaire, 1831) in the French Bibliothèque universelle, so Cryptosaurus was never preoccupied and Cryptodraco is an unnecessary replacement name.

References

  1. Seeley, H. G. (1875). On the femur of Cryptosaurus eumerus, Seeley, a Dinosaur from the Oxford Clay of Great Gransden. Quarterly Journal of the Geological Society of London 31(1-4): 149-151. Geological Society of London. doi:10.1144/gsl.jgs.1875.031.01-04.12

    Describes the femur as from the Oxford Clay of Great Gransden, the source of the locality.

    seeley1875b
  2. Seeley, H. G. (1869). Index to the fossil remains of Aves, Ornithosauria, and Reptilia, from the Secondary System of Strata, arranged in the Woodwardian Museum of the University of Cambridge. 1-143. Deighton, Bell, and Co..

    Coins the name Cryptosaurus eumerus with a brief shelf-location note but no diagnosis or description — a nomen-nudum precursor to the 1875 description.

    seeley1869b
  3. Geoffroy Saint-Hilaire, É. (1831). Recherches sur de grands sauriens trouvés à l'état fossile vers les confins maritimes de la Basse-Normandie, attribués d'abord au crocodile, puis déterminés sous les noms de Téléosaurus et Sténéosaurus [Researches on large saurians found in the fossil state toward the maritime borders of Lower Normandy, at first attributed to the crocodile, then determined under the names Teleosaurus and Steneosaurus]. 1-138. Firmin Didot, Paris.

    Introduced the nomen nudum Cystosaurus; a later misspelling of this name led Lydekker (1889) to treat Cryptosaurus as preoccupied and propose the replacement name Cryptodraco.

    geoffroysaint-hilaire1831a
  4. Lydekker, R. (1889). On the remains and affinities of five genera of Mesozoic reptiles. Quarterly Journal of the Geological Society of London 45(1-4): 41-59. Geological Society of London. doi:10.1144/GSL.JGS.1889.045.01-04.04

    Proposed the replacement name Cryptodraco for Cryptosaurus.

    lydekker1889b
  5. Naish, D.; Martill, D. M. (2008). Dinosaurs of Great Britain and the role of the Geological Society of London in their discovery: Ornithischia. Journal of the Geological Society 165(3): 613-623. Geological Society of London. doi:10.1144/0016-76492007-154

    Finds that Cryptosaurus lacks autapomorphies and regards it as Ankylosauria indet.

    naish2008a
  6. Galton, P. M. (1980). European Jurassic ornithopod dinosaurs of the families Hypsilophodontidae and Camptosauridae. Neues Jahrbuch für Geologie und Paläontologie - Abhandlungen 160(1): 73-95. Schweizerbart. doi:10.1127/njgpa/160/1980/73

    Compares the femur with that of the ankylosaur Hoplitosaurus and moves it from the ornithopods toward the nodosaurids.

    galton1980a