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Hypselospinus

Norman, 2010 HIP-sel-o-SPIEN-us

From Greek 'hypselos' meaning 'high' and Latin 'spina' meaning 'spine' or 'thorn', in reference to the tall neural spines on the vertebrae.

137.1–132.6 million years ago Valanginian, Early Cretaceous
Early Cretaceous stages

Hypselospinus is a genus of iguanodontian dinosaur which was first described as a species of Iguanodon (I. fittoni) by Richard Lydekker in 1889, the specific name honoring William Henry Fitton.

Diagnosis

  1. Preacetabular process vertically orientated, laterally compressed and comparatively deep proximally
  2. Ventral edge of preacetabular process thicker than dorsal edge
  3. Dorsal edge of iliac blade transversely compressed
  4. Dorsal edge of iliac blade straight in profile rather than bowed dorsally
  5. Postacetabular blade tapers to blunt, thickened bar with strong medial inturning to form thick shelf roofing well-defined brevis fossa
  6. Brevis fossa bordered laterally by horizontal ridge
  7. Ventral surfaces of posterior sacral centra bear midline keels
  8. Anterior caudal vertebral centrum with cylindrical proportions bearing well-marked haemal facet posteriorly
  9. Neural spines of dorsal, sacral and proximal caudal series singularly slender and elongate

Species

Hypselospinus fittoni (Lydekker, 1889)

Type species

First named as Iguanodon fittoni

Named for William Henry Fitton, who had worked in the Early Cretaceous strata of England.

Holotype
NHMUK PV R 1635 , Natural History Museum
Material
Ilium and associated elements comprising posterior sacrum, anterior caudal centrum
Horizon
Wadhurst Clay Formation, Valanginian, Early Cretaceous , 137.1–132.6 million years ago
Locality
Shornden Quarry, East Sussex, United Kingdom

Synonyms

  • Huxleysaurus junior subjective

    Currently regarded as a junior synonym of Hypselospinus fittoni, though this may change with additional material.

  • Iguanodon fittoni reassigned

    Original combination established by Lydekker (1889); reassigned to the new genus Hypselospinus by Norman (2010).

  • Iguanodon hollingtoniensis junior subjective

    Treated as a junior synonym of Hypselospinus fittoni by Norman (2010).

  • Wadhurstia junior objective

    Originally described as Iguanodon fittoni and then re-erected as Wadhurstia; the material is now placed in Hypselospinus fittoni, with Wadhurstia treated as a junior synonym.

Synonyms of the genus

Name Type Reason
Darwinsaurus junior subjective Erected by Paul (2012) from material previously assigned to Hypselospinus fittoni; the genus remains contested but is currently treated as a synonym.

References

  1. Norman, D. B. (2010). A taxonomy of iguanodontians (Dinosauria: Ornithopoda) from the lower Wealden Group (Cretaceous: Valanginian) of southern England. Zootaxa 2489(1): 47-66. Magnolia Press. doi:10.11646/zootaxa.2489.1.3 norman2010a
  2. Paul, G. S. (2024). The Princeton Field Guide to Dinosaurs (3rd ed.). Princeton University Press.

    Source of the mass estimate.

    paul2024a
  3. Galton, P. M. (2009). Notes on Neocomian (Lower Cretaceous) ornithopod dinosaurs from England - Hypsilophodon, Valdosaurus, "Camptosaurus", "Iguanodon" - and referred specimens from Romania and elsewhere. Revue de Paléobiologie, Genève 28(1): 211-273.

    Prints the National Grid reference for Shornden Quarry and places this taxon above the horizon that yielded Barilium's type.

    galton2009a
  4. Paul, G. S. (2012). Notes on the rising diversity of iguanodont taxa, and iguanodonts named after Darwin, Huxley, and evolutionary science. Actas de V Jornadas Internacionales sobre Paleontología de Dinosaurios y su Entorno, Salas de los Infantes, Burgos 121-131. Colectivo Arqueológico-Paleontológico de Salas de los Infantes (Burgos). paul2012a
  5. Lydekker, R. (1889). Note on new and other dinosaurian remains. Geological Magazine 6: 352-356. doi:10.1017/S0016756800176587 lydekker1889c