Wessex Formation

Wessex Formation
Stratigraphic range: Barremian, 130–126Ma
↓

The Undercliff near Shalcombe, Isle of Wight
Type Geological formation
Unit of Wealden Group
Underlies Vectis Formation
Overlies Lower Wealden Clay Formation
Location
Region England
Country  UK

The Wessex Formation is a fossil-rich English geological formation that dates to the Barremian stage (about 130 million years ago) of the Early Cretaceous. It is part of the Wealden Group and underlies the younger Vectis Formation.

Geological map of southeast England (Horace B. Woodward, 1904) (for index of colours see London basin map)

Fauna

Color key
Taxon Reclassified taxon Taxon falsely reported as present Dubious taxon or junior synonym Ichnotaxon Ootaxon Morphotaxon
 Notes
Uncertain or tentative taxa are in small text; crossed out taxa are discredited.

Invertebrates

Invertebrates are commonly preserved in the Wessex Formation. Freshwater bivalves can be found including unionoids such as Margaritifera, Nippononaia, and Unio. These bivalves are helpful in reconstructing what the freshwater paleoenvironment may have been like during the formation's deposition. Specimens of Viviparus, a genus of freshwater snail, have also been found. Cretamygale chasei, a species of Mygalomorph spider, has been described from a specimen found in amber. It is believed to be the oldest known Nemesiid and the second oldest Mygalomorph.[1]

Cartilaginous fishes

Cartilaginous fishes of the Wessex Formation
Genus Species Location Stratigraphic Position Abundance Note Images

Hybodus

H. basanus
Hybodus

Hylaeobatis

H. problematica

Palaeoscyllium

Indeterminate

Vectiselachos

V. ornatus

Ray-finned fish

Ray-finned fishes of the Wessex Formation
Genus Species Location Stratigraphic Position Abundance Notes Images

Caturus

Indeterminate
Coelodus

Coelodus

Indeterminate

Lepidotes

Indeterminate

Turtles

Turtles of the Wessex Formation
Genus Species Location Stratigraphic Position Abundance Notes

Helochelydra

H. nopcsai

Brodiechelys

B. brodiei

Crurotarsans

Crurotarsans of the Wessex Formation
Genus Species Location Stratigraphic Position Abundance Notes Images

Anteophthalmosuchus[2]

A. hooleyi[2]

Hylaeochampsa

H. vectiana

Koumpiodontosuchus[3]

K. aprosdokiti[3]

Leiokarinosuchus[2]

L. brookensis[2]

Vectisuchus

V. leptognathus

Pterosaurs

Pterosaurs of the Wessex Formation
Genus Species Location Stratigraphic Position Abundance Notes Images

Caulkicephalus

C. trimicrodon
Caulkicephalus

Istiodactylus

I. latidens

Ornithocheirus

Indeterminate

"Ornithodesmus"

"O." latidens

Reclassified as Istiodactylus latidens

Dinosaurs

Ornithischians

Ornithischians reported from the Wessex Formation
Genus Species Location Stratigraphic Position Material Notes Images

Dollodon

D. bampingi

Junior synonym of Mantellisaurus atherfieldensis
Hypsilophodon foxii

Hypsilophodon

H. foxii

Iguanodon

I. seelyi

Junior synonym of Iguanodon bernissartensis

I. bernissartensis

Specimens classified as Iguanodon seelyi are referable to this species

Mantellisaurus

M. atherfieldensis

Polacanthoides

P. ponderosus

"Tibia."[4]

Polacanthus

P. foxii

P. rudgwickensis

Valdosaurus

V. canaliculatus

Sauropods

Indeterminate diplodicoid and rebbachisaurid remains are known from the formation.

Sauropods reported from the Wessex Formation
Genus Species Location Stratigraphic Position Material Notes Images

Chondrosteosaurus

C. gigas

"Several cervical vertebrae."[5]

Eucamerotus

E. foxi

"Dorsal vertebra."[5]

Iuticosaurus

I. valdensis

"Several caudal vertebrae."[5]

Oplosaurus

O. armatus

"Tooth."[6]

Ornithopsis

O. eucamerotus

"Ischia and pubis."[5]

O. hulkei

One dorsal vertebra.[7]

Theropods

Indeterminate velociraptorine remains have been recovered from the Wessex Formation.

Theropods reported from the Wessex Formation
Genus Species Location Stratigraphic Position Material Notes Images

Aristosuchus

A. pussilis

"Sacrum and pubes."[8]

A compsognathid
Baryonyx walkeri
Neovenator salterii

Baryonyx

B. walkeri

Isolated teeth

A spinosaurid possibly synonymous with Suchosaurus cultridens

Calamosaurus

C. foxi

"Vertebrae."[9]

A compsognathid

Calamospondylus

C. oweni

"Vertebrae."[9]

A possible oviraptorosaur

Eotyrannus

E. lengi

"Partial skull and skeleton."[10]

A tyrannosauroid

Neovenator

N. salerii

"Partial skull and skeleton."[11]

A carcharodontosaurian

Ornithodesmus

O. cluniculus

A dubious species of dromaeosaurid, once misidentified as a pterosaur

Thecocoelurus

T. daviesi

"Cervical vertebrae."[12]

A coelurosaur of uncertain classification

"Thecospondylus"

T. daviesi

Name preoccupied, renamed Thecocoelurus daviesi

Yaverlandia

Y. bitholus

A maniraptoran of uncertain classification, originally identified as an ornithischian

See also

References

  1. ↑ Selden, Paul A. (2003). First British Mesozoic Spider, From Cretaceous Amber Of The Isle Of Wight, Southern England. Palaeontology 45(5): 973-983
  2. ↑ 2.0 2.1 2.2 2.3 Steven W. Salisbury and Darren Naish (2011). "Crocodilians". In Batten, D. J. (eds). English Wealden Fossils. The Palaeontological Association (London). pp. 305–369.
  3. ↑ 3.0 3.1 Sweetman, S.C., Pedreira-Segade, U., and Vidovic, S.U. 2014. A new bernissartiid crocodyliform from the Lower Cre- taceous Wessex Formation (Wealden Group, Barremian) of the Isle of Wight, southern England. Acta Palaeontologica Polonica. http://www.app.pan.pl/archive/published/app59/app000382013_acc.pdf
  4. ↑ "Table 17.1," in Weishampel, et al. (2004). Page 368.
  5. ↑ 5.0 5.1 5.2 5.3 "Table 13.1," in Weishampel, et al. (2004). Page 271.
  6. ↑ "Table 13.1," in Weishampel, et al. (2004). Page 261.
  7. ↑ "Table 13.1," in Weishampel, et al. (2004). Page 266.
  8. ↑ "Table 4.1," in Weishampel, et al. (2004). Page 76.
  9. ↑ 9.0 9.1 "Table 4.1," in Weishampel, et al. (2004). Page 78.
  10. ↑ "Table 5.1," in Weishampel, et al. (2004). Page 112.
  11. ↑ "Table 4.1," in Weishampel, et al. (2004). Page 75.
  12. ↑ "Table 8.1," in Weishampel, et al. (2004). Page 167.

External links