Holotype: BMNH 41955

Locality: Smallmouth Sands, Weymouth, (SY 669764-SY 672772), Dorset County, England, Southern United Kingdom.

Horizon: Lower Kimmeridgian Clay.

Biostratigraphy:

Age: Early Kimmeridgian Stage, Middle Malm Epoch, Late Jurassic.

Material: Cervical vertebrae.

Referred material:

Locality: Boulogne-sur-mer, Pas-de-Calais Department, France.

Horizon:

Biostratigraphy: Aulacostephanus pseudomutabilis zone.

Age: Middle Kimmeridgian Stage, Middle Malm Epoch, Late Jurassic.

Material:

Number: Not given: Vertebrae.

= Plesiosaurus infraplanus SAUVAGE, 1879 non PHILLIPS, 1871

Holotype:

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Age:

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= Plesiosaurus plicatus SAUVAGE, 1879
Etymology:

Holotype:

Locality:

Horizon:

Biostraigraphy:

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= Plesiosaurus doedicomus OWEN, ?1840
Etymology:

Holotype:

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Species: purbecki BOGOLOBOV, 1911 (nomen dubium)
Etymology:

Holotype: MGRI

Locality: Tartarovo, the Moscow basin, European Russia.

Horizon: Volgian, Portlandian.

Biostratigraphy:

Age: Tithonian Stage, Upper Malm Epoch, Late Jurassic.

Material: Vertebrae.
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Species: elasmosauroides BOGOLOBOV, 1911 (nomen dubium)
Etymology:

Holotype: MGRI

Locality: The Moscow Basin, European Russia.

Horizon: Volgian, Portlandian.

Biostratigraphy:

Age: Tithonian Stage, Upper Malm Epoch, Late Jurassic.

Material: Vertebrae.
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Species: mazetieri BIGOT, 1938 (nomen dubium)
Etymology:

Holotype:

Locality: Tuilerie, Fresne D'Argences, Calvados Department, France.

Horizon:

Biostratigraphy:

Age: Callovian Stage, Upper Dogger Epoch, Late Jurassic.

Material: Anterior portion of a skull.
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Species: kamensis DUBEIKOVSKII & OCHEV, 1967 (nomen dubium)
Etymology:

Holotype: sGU 104a/16

Locality: Kama River Basin, Kostroma Region, European Russia.

Horizon: Volgian.

Biostratigraphy:

Age: Late Jurassic.

Material: Cervical region.
Note: Now lost.