Genus: Helochelydra NOPCSA, 1928 emend LAPPARENT de BRION & MURELAGA, 1999
Etymology:
= Helochelydra NOPCSA, 1928 (nomen dubium, nomen inquirendum)

Species: nopcsai LAPPARENT & MURELAGA, 1999
Etymology: In honor of Baron Ferenc Nopsca.

Holotype: NHMUK (BMNH) R 171

Locality: Brook, Isle of Wight County, England, Southern United Kingdom.

Horizon: Wealden.

Biostratigraphy:

Age: Valanginian-Barremian Stage, Lowermost Neocomian Subepoch, Lowermost Early Cretaceous Epoch, Early Cretaceous.

Material: A partial shell.

Referred material:

JOYCE, CHAPMAN, MOODY & WALKER, 2011

Locality: Brightstone Bay, Isle of Wight County, England, Southern United Kingdom.

Horizon: Wessex Formation, Wealden Group.

Biostratigraphy:

Age: Valanginian-Hauterivian Stage, Neocomian Subepoch- Barremian Stage, Lower Gallic Subepoch, Early Cretaceous Epoch, Early Cretaceous.

Material:

IWCMS 1998.21: Nearly complete skull and mandible with associated postcranial remains.

IWCMS 2002.22: Shell fragment.

NHMUK R5195: Proximal costal.

NHMUK R5196: 4 shell fragments.

NHMUK R5197: Peripheral fragment.

NHMUK R5198: Peripheral fragment.

NHMUK R5199: Plastral fragment.

NHMUK R5201: Peripheral fragment.

NHMUK R5202: Peripheral fragment.

NHMUK R5238: Costal fragment.

NHMUK R16583: Near-complete left hyoplastron.

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Species: bakewelli (MANTELL, 1827) JOYCE, CHAPMAN, MOODY & WALKER, 2011
= Trionyx bakewelli MANTELL, 1827
= Helochelydra bakewelli (MANTELL, 1827) NOPCSA, 1928
= Tretosternon bakewelli (MANTELL, 1827) OWEN, 1842
= Compsemys bakewelli JOYCE, CHAPMAN, MOODY & WALKER, 2011
Etymology:

Holotype: HASTM GG92/96

Locality: Hastings, (TQ 831095-TQ 853105), East Sussex County, England, Southern United Kingdom.

Horizon: Hastings Beds, (Ashdown Beds, Tunbridge Wells Sand).

Biostratigraphy:

Age: Berriasian-Valanginian Stage, Lower Neocomian Substage, Lowermost Early Cretaceous Epoch, Early Cretaceous.

Material:

Referred material:

NHMUK R970a: 1 plastron and 1 costal fragment.

NHMUK R970b: Isolated posterior right costal.

NHMUK R5891: Plastal fragment.

 

Locality: Brede Bone-Bed, Hastings, East Sussex County, England, Southern United Kingdom.

Horizon: Wealden Formation.

Biostratigraphy:

Age: Early Cretaceous.

Material:

Number: Not given:

 


BENTON & SPENCER, 1995

Locality: Black Horse Quarry, Telham, (TQ 769142), East Sussex County, England, Southern United Kingdom.

Horizon: Hastings beds.

Biostratigraphy:

Age: Valanginian, Neocomian Substage, Lowermost Early Cretaceous Epoch, Early Cretaceous.

Material:

Number: Not given: Broken plasteron and carapace bones.

 


Locality: From the Upper Silty Bed north of the sea wall below Yaverland Battery, Sandown, Isle of Wight County, England, Southern United Kingdom.

Horizon: Upper Wealden Group, Wessex Formation.

Biostratigraphy:

Age: Upper Barremian, Lowermost Neocomian Substage, Lowermost Early Cretaceous Epoch, Early Cretaceous.

Material:

Number: Not given: Partial carapace.

 

JOYCE, CHAPMAN, MOODY & WALKER, 2011

Locality: Cuckfield, West Sussex County, England, Southern United Kingdom.

Horizon: 'Cuckfield Stone', Hastings Sub-Group.

Biostratigraphy:

Age: Berriasian-Valanginian Stage, Lower Neocomian Substage, Lowermost Early Cretaceous Epoch, Early Cretaceous.

Material:

NHMUK 2775x: Left xiphiplastron.

NHMUK 2776: Median portion of right hyoplastron.

NHMUK 3528: Proximal costal.

NHMUK 3543a: 2 plastral fragments.

NHMUK 3598: Isolated right epiplastron.

NHMUK 26029: Shell fragment.

LYDEKKER, 1889

BMNH 2265: Dorsal surface of a costal bone.

BMNH 2276: Imperfect right hypoplastral.

BMNH 3543: The inguinal region of the rigth hyoplastral.

BMNH 3543a: The axillary retiong of the right hyoplastral.

BMNH 3375x: Eht levf xiphiplastral.

BMNH 25029: Fragment fo sandstone, showing the outer surface of a small portion of the carapace.

BMNH 39213: posterior marginal bone.

BMNH 3528: Costal of a small individual.

BMNH 3598: The anterior extremity of the plastron, imperfect on the left side.

 

Locality: Tilgate, West Sussex County, England, Southern United Kingdom.

Horizon: 'Cuckfield Stone', Hastings Sub-Group.

Biostratigraphy:

Age: Berriasian-Valanginian Stage, Lower Neocomian Substage, Lowermost Early Cretaceous Epoch, Early Cretaceous.

Material:

NHUMK 3507, 3509-3511, 3521, 3524, 28411: Shell fragments.

NHMUK 3531: Small shell fragment.

 

Locality: Battle, East Sussex County, England, Southern United Kingdom.

Horizon: Hastings Sub-Group.

Biostratigraphy:

Age: Berriasian-Valanginian Stage, Lower Neocomian Substage, Lowermost Early Cretaceous Epoch, Early Cretaceous.

Material:

NHMUK 5644: Peripheral fragment.

NHMUK R658: Partial left hyoplastron.

NHMUK 39213: 4 isolated shell fragments.

LYDEKKEr, 1889

BMNH R 658: Imperfect left hyoplastral

 

NAISH & SWEETMAN, 2011

Locality: Pevensey Pit, Ashdown Brickworks, northwest of Bexhill, East Sussex County, England, Southern United Kingdom.

Horizon: Wadhurst Clay Formation, Hastings Group.

Biostratigraphy:

Age: Valanginian Stage, Middle Neocomian Subepoch, Lower Early Cretaceous Epoch, Early Cretaceous.

Material:

Number: Not given:

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= Helochelydra (no species name) NOPCSA, 1928

Holotype: BMNH R171

Locality: Brook-Atherfield, Isle of Wight County, England, Southern United Kingdom.

Horizon: Wealden Formation.

Biostratigraphy:

Age: Early Cretaceous.

Material:

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Species: anglica (LYDEKKER, 1889) MILNER, 2004
Etymology:
= Tresternum punctatum LYDEKKER & BOULENGER, 1887 non OWEN, 1842
= Tresternum punctatum MANSELL-PLEYDELL, 1888 non OWEN, 1842
= Tresternum punctatum LYDEKKER, 1889 non OWEN, 1842
= Platychelys ?anglica LYDEKKER, 1889
= Tresternum punctatum DELAIR, 1958 non OWEN, 1842
= Tresternum bakewelli DELAIR, 1958
= Compsemys anglica (LYDEKKER, 1889) JOYCE, CHAPMAN, MOODY & WALKER, 2011

Holotype: BMNH 48357

Locality: Durlston Bay, Dorset County, England, Southern United Kingdom.

Horizon: Purbeck Limestone Group, Portland stone-Upper Purbeck Beds.

Biostratigraphy:

Age: Portlandian, Uppermost Tithonian Stage, Uppermost Malm Epoch, Late Jurassic- Berriasian Stage, Lowermost Neocomian Substage, Lowermost Early Cretaceous Epoch, Early Cretaceous.

Material: Partial posterior carapace.

Referred material:

BMNH 46325: Partial plastron.

BMNH 48349: Fragmentary specimen.

 

Locality: Beckles Pit, Durlston Bay, Dorset County, England, Southern United Kingdom.

Horizon: Purbeck Limestone Group, Portland stone-Upper Purbeck Beds.

Biostratigraphy:

Age: Portlandian, Uppermost Tithonian Stage, Uppermost Malm Epoch, Late Jurassic- Berriasian Stage, Lowermost Neocomian Substage, Lowermost Early Cretaceous Epoch, Early Cretaceous.

Material:

BMNH 48352: Block number for assorted costal plates.

MANCH L9522: Partial plastron and underside of carapace of a small specimen.

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