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: