Genus: Thalassiodracon STORRS & TAYLOR, 1996
Etymology: Greek, thalassa, "sea" and Greek, dracon, "dragon": Sea Dragon.
= Hezatarostinus HAWKINS, 1840 (sic)
Etymology: Greek, hexa, “six”, Greek, tarsos, “tarsus” and Greek, ostinos, “bony”: Six-tarsal boned.

Species: hawkinsii (OWEN, 1840) STORRS & TAYLOR, 1996
Etymology:
= Plesiosaurus triotarsostinus HAWKINS, 1834
Etymology:
= Plesiosaurus tessarestarostrinus HAWKINS, 1834 (sic)
= Plesiosaurus hawkinsii OWEN, 1840
= Plesiosaurus hawkinsi (OWEN, 1840) LYDEKKER, 1889 (sic)

Lectotype: NHMUK (BMNH) 2018

Locality: Street, Somersetshire County, England, Southern United Kingdom.

Horizon: Blue Lias Formation, Lower Lias Group.

Biostratigraphy: Pre-planorbis beds.

Age: Rhaetian Stage, Uppermost Late Triassic Epoch, Latest Triassic or Hettangian Stage, Lowermost Lias Epoch, Earliest Jurassic.

Material: Skull and cervical vertebrae.

Referred material:

OWEN, 1854

ROYAL COLLEGE OF SURGEONS 222: Cast of type.

STORRS & TAYLOR, 1996

Uncat: ANSP 15767, 51235, BMNH 2020 (14551), 2021, 2022 (14549), 2039, 14550, R.1331, ?R.45, CAMSM J.46986, J.35181, ?J.35180, MM L.97677, RM 4110 (excluding “head” and tail which are from separate individuals [McGowan, 1990, (GWS), 1993]), SWM uncat, TTNCM 8345, 8348/9291, UCD uncat.
Note: Note: Found with a gastrolith in OUM J.10337.

 

BUCKLAND

Locality: Lyme Regis coast, Pinhay Bay- Charmouth, (SY 3291-SY 3794), Dorset County, England, Southern United Kingdom.

Horizon:

Biostratigraphy: Caenisites obtusum zone.

Age: Hettangian-Pliensbachian Stage, Lower Lias Epoch, Early Early Jurassic.

Material:

Number: Not given: Skull and skeleton.

 

= Plesiosaurus etheridgii HAWKINS, 1834
Etymology:

Holotype: BGS GSM 51235

Locality: Street, Dorset County, England, Southern United Kingdom.

Horizon:

Biostratigraphy:

Age: Lower Lias Epoch, Early Early Jurassic.

Material: Skull and skeleton.

 

Paralectotype:

= Plesiosaurus? pentatarsostinus HAWKINS, 1834
Etymology:

Holotype: NHMUK 2020 [14551]

Locality:

Horizon:

Biostratigraphy:

Age:

Material:

 

Paralectotype:

= Plesiosaurus hexatarsostinus HAWKINS, 1834
Etymology:
= Hezatarostinus HAWKINS, 1840 (sic)

Holotype: NHMUK 2022 [14549]

Locality: Dorset County, England, Southern United Kingdom.

Horizon:

Biostratigraphy:

Age:

Material:

 

= Plesiosaurus cliduchus SEELEY, 1865
Etymology:

Holotype: Woodwardian Museum, CAMSM J.35180

Locality: Street, Somerset County, England, Southern United Kingdom.

Horizon:

Biostratigraphy:

Age: Lias Epoch, Early Jurassic.

Material: Fragmentary skeleton.

 

= Plesiosaurus eleutheraxon SEELEY, 1865 (nomen dubium)
Etymology:

Holotype: CAMSM J.35181

Locality: Street, Somersetshire County, England, Southern United Kingdom.

Horizon:

Biostratigraphy:

Age: Lower Lias Epoch, Early Early Jurassic.

Material: Vertebrae and limb bones.

Referred material:

Locality: Lyme Regis coast, Pinhay Bay- Charmouth, (SY 3291-SY 3794), Dorset County, England, Southern United Kingdom.

Horizon:

Biostratigraphy: Caenisites obtusum zone.

Age: Hettangian-Pliensbachian Stage, Lower Lias Epoch, Early Early Jurassic.

Material:

BMNH 39851:

BMNH 41102:

BMNH R227: