Walton, west of Street: Early/Lower Hettangian, United Kingdom

List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
Reptilia - Plesiosauria - Pliosauridae
1 individual
NHMUK 2021*
    = Plesiosaurus hawkinsi Owen 1840
Lydekker 1888
recombined as Thalassiodracon hawkinsii
Reptilia - Ichthyosauridae
Ichthyosaurus chiroparamekostinus Hawkins 1834
1 individual
synonym of Ichthyosaurus communis
tail, paddle
Ichthyosaurus chirostrongulostinus Hawkins 1834
1 individual
synonym of Ichthyosaurus tenuirostris
snout
Ichthyosaurus larkini n. sp. Lomax and Massare 2017
Lomax and Massare 2017 1 specimen
BRSUG 25300 (holotype), nearly complete skeleton, previously identified as I. communis
see common names

Geography
Country:United Kingdom State/province:England County:Somerset
Coordinates: 51.1° North, 2.8° West (view map)
Paleocoordinates:37.3° North, 1.2° East
Basis of coordinate:based on nearby landmark
Geographic resolution:outcrop
Time
Period:Jurassic Epoch:Early/Lower Jurassic
Stage:Hettangian 10 m.y. bin:Jurassic 1
Key time interval:Early/Lower Hettangian Ammonoid zone: Psiloceras tilmanni
Age range of interval:201.40000 - 199.50000 m.y. ago
Stratigraphy
Geological group:Lias Formation:Blue Lias
Stratigraphic resolution:bed
Stratigraphy comments: Earliest Hettangian (Benson et al. 2013). PJW: Originally given as Pre-planorbis zone; the Psiloceras tilmanni is the only Jurassic ammonoid zone preceding the Psiloceras planorbis zone.
Lithology and environment
Primary lithology: not reported
Environment:marine indet.
Taphonomy
Modes of preservation:body
Size of fossils:macrofossils
Preservation of anatomical detail:good
Abundance in sediment:rare
Fragmentation:occasional
Spatial resolution:parautochthonous
Collection methods and comments
Collection methods:survey of museum collection
Collection size:1 specimens
Reason for describing collection:general faunal/floral analysis
Museum repositories:BMNH
Metadata
Database number:110213
Authorizer:M. Carrano, A. Dunhill Enterer:H. Street, B. Allen, M. Carrano
Modifier:P. Wagner Research group:vertebrate
Created:2011-06-04 05:42:08 Last modified:2021-02-17 20:54:15
Access level:the public Released:2011-06-04 05:42:08
Creative Commons license:CC BY
Reference information

Primary reference:
49835. T. Hawkins. 1834. Memoirs of Ichthyosauri and Plesiosauri, Extinct Monsters of the Ancient Earth vi-51 [M. Carrano/M. Carrano]

Secondary references:

36328ETE R. B. J. Benson, K. T. Bates, M. R. Johnson and P. J. Withers. 2011. Cranial anatomy of Thalassiodracon hawkinsii (Reptilia, Plesiosauria) from the Early Jurassic of Somerset, United Kingdom. Journal of Vertebrate Paleontology 31(3):562-574 [M. Carrano/H. Street/R. Benson]
41463 R. B. J. Benson, M. Evans, and P. S. Druckenmiller. 2012. High diversity, low disparity and small body size in plesiosaurs (Reptilia, Sauropterygia) from the Triassic–Jurassic boundary. PLoS ONE 7(3):e31838 [R. Benson/R. Benson]
67965 D. R. Lomax and J. A. Massare. 2017. Two new species of Ichthyosaurus from the lowermost Jurassic (Hettangian) of Somerset, England. Papers in Palaeontology 3(1):1-20 [A. Dunhill/B. Allen]
14142ETE R. Lydekker. 1888. Catalogue of the Fossil Reptilia and Amphibia in the British Museum (Natural History). Part I. Containing the Orders Ornithosauria, Crocodilia, Dinosauria, Squamata, Rhynchocephalia, and Proterosauria. British Museum (Natural History), London 1-309 [M. Carrano/M. Carrano/M. Uhen]