Species: leedsii SEELEY, 1874
Etymology:
= Plesiosaurus leedsi (SEELEY, 1874) WHIDBORNE, 1881

Holotype: Leeds Collection, BMNH R2421

Locality: From an unspecified brick-pit near Peterbourgh, Cambridgeshire County, England, Southern United Kingdom.

Horizon: Oxford Clay.

Biostratigraphy:

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

Material: Basioccipital, exoccipitals, basisphenoid, parts of maxilla, premaxillae, portions of parietals, and frontals, portions of the mandible, 44 cervical vertebrae, 2 pectorals, 19 dorsals, and 12 sacrals and caudals, many of the vertebrae have the fused neural arches preserved, and in some of the cervicals and caudals the ribs are preserved, dorsal ribs, portions of coracoids and scapulae, fore paddles, ilium, ischia, hind paddle.

Dorsal and ventral view of front half of skull, dentary and occipit (ANDREWS, 1913).

Teeth (ANDREWS, 1913).

1) Atlas and axis; 2) Anterior cervical vertebra; 3) Middle cervical vertbra; 4) Posterior cervical vertebra; 5) Anterior dorsal vertebra; 6) Anterior caudal vertebra; 7) Left fore paddle from above; 8) Left ilium; 9) Left ischium; 10) Right hind paddle from above (ANDREWS, 1913).

Skull of Muraenosaurus modifed from Andrews, 1909. A) Dorsal; B) lateral with jaws closed; C) Lateral with jaws open and D) ventral view of skull.

Muraenosaurus leedsii skull after Evans (1999).

Skeleton from Andrews, 1910.

Referred material:

BMNH R2422: Basioccipital, basisphenoid, exoccipital, and opisthotic, a nearly complete mandible, atlas, axis, 42 cervicals, 19 dorsals, and 24 caudals, numerous ribs, imperfect shoulder-girdle, fore paddles, ilia, ischium, part of pubis and hind paddles.

BMNH R2423: Basiocciptial, basisphenoid, supraoccipital, part of squamosal, the articular portions of the mandible, atlas, axis, 40 cervical vertebrae wanting ribs and arches, 19 dorsals, and 19 caudals, crushed neural arches, fragments of scapulae and ischium, humeri, femora, epipodials, and other bones of the paddle.

BMNH R2424: 34 cervicals, 2 pectorals, 23 dorsals including 2 sacrals, 19 caudals, cervical and caudal ribs, 5 complete neural arches, 4 dorsal and 1 caudal, with portions of several others are preserved. Several cervical ribs and several more or less nearly complete dorsal ribs are present, right humerus, radius, ulna, 1 ischia, part of a pubis, both femora and some bones of the hind paddle of a juvenile.

BMNH R2426: Incomplete postcranial.

BMNH R2864: Basioccipital, basisphenoid with part of parasphenoid, portions of exoccipitals, of frontals, and of premaxillae, vomer and part of the pteryogid, quadrate, greater part of mandible, several detached teeth, 45 cervical and pectoral vertebrae, 20 dorsals (and ?sacral) vertebrae, 20 caudals with some caudal ribs and chevrons, portions of the limb girdles, the fore and hind paddles.

BMNH R3704: Shoulder-girdle of an old adult.

EVANS, 1999

LEICT G18.1996: Fragmentary skull and skeleton.

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BARDET & PENNETIER, 1991, BARDET, 1993

Locality: Sea-cliff of Benerville, Calvados Department, Normandy, France.

Horizon:

Biostratigraphy:

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

Material: The left side of a pectoral girdle and 3 cervical vertebrae.

Collection of G. & E. PENNETIER: An hemipectoral girdle and 3 associated cervical vertebrae.

 

BROWN & KEEN, 1991

Locality: Kellaways Sand of Lincolnshire, Dorset County, England, Southern United Kingdom.

Horizon: Kellaways Formation.

Biostratigraphy:

Age: Lower Callovian Stage, Upper Dogger Epoch, Middle Jurassic.

Material:

SCUNM.P2916: Mandible, small fragments of a splenial may be fused to its medial aspects, but the remaining elements have separated post-mortem and were not found, and several teeth.

 

FOFFA, YOUNG & BRUSATTE, 2018

Locality: Peterborough, Cambridgeshire County, England, Southern Unitied Kingdom.

Horizon: Corallian Group.

Biostratigraphy:

Age: Lower to Middle Oxfordian Stage, Lower Malm Epoch, Lower Late Jurassic.

Material:

NHMUK PV R 2861: Tooth.

 

PERSSON

Locality: The Oblast of Riasan, European Russia.

Horizon:

Biostratigraphy:

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

Material:

Number: Not given: Vertebrae.

 

= Muraenosaurus cf. leedsi ZVERKOV, ARKHANGELSKY, GULYAEV, IPPOLITOV & SHMAKOV, 2024

Locality: Alpatyevo, Lukhovitsy District, Moscow Region, European Russia.

Horizon:

Biostratigraphy: C. enodatum Subzone, S. calloviensie Zone.

Age: Lower Callovian Stage?, Dogger Epoch, Middle Jurassic.

Material:

SGM 1358-37: Cervical vertebra.

 

 

= Cimoliasaurus durobrivensis LYDEKKER, 1889
Etymology:
= Muraenosaurus durobrivensis (LYDEKKER, 1889) ANDREWS, 1909
= Tremamesacleis durobrivensis (LYDEKKER, 1889) WHITE, 1940

Holotype: BMNH R2628(2428?)

Locality: Peterbough, Cambridgeshire County, England, Southern United Kingdom.

Horizon: Oxford Clay.

Biostratigraphy:

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

Material: 29 cervicals, 2 pectorals, 14 dorsals and some caudals, coracoids and scapulae, imperfect fore paddles, ilia, ischia, and 1 pubis, incomplete hind paddles.

1) Centrum of anterior cervical vertebra; 2) Centrum of middle cervical vertebra; 3) Centrum of posterior cervical vertebra; 4) Pectoral vetrtebra; 5) Centrum of dorsal vertebra; 6) Centrum of anterior caudal vertebra; 7) Centrum of postrior caudal vertebra; 8) Right ilium; 8) Right ischium; 10) Ventral face of interclavicle; 11) Right humerus; 12) Right femur (ANDREWS, 1913).

Referred material:

BMNH R2863: Fragments of skull and mandible, 42 cervical vertebrae, 2 pectorals, 21 dorsals and 8 sacrals, and caudal vertebrae, numerous ribs, ventral ribs, coracoids, scapulae and interclavicle, humerus and some other bones of fore paddle, ilia, ischia, pubes, femora and some other bones of the hind paddles.

BMNH R2427: Basioccipital and basisphenoid, exoccipitals, premaxilla, parts of mandible including the symphysial regions the atlas and axis, and 36 cervical vertebrae, the fused neural arches and cervical ribs, broken away in nearly all cases, 11 dorsal and 13 caudal vertebrae some with arches and ribs, numerous ribs, dorsal and ventral, chevrons, imperfect shoulder-girdle, ischium, ? femur, tibia, and fibula.
Note: Paleopathology, 2 humeri shows avascular necrosis (ROTHSCHILDS & STORRS, 2003)

BMNH R2681: Basioccipital, exoccipital, opisthotic, and supraoccipital, a nearly complete mandible, atlas, axis, 27 cervicals, mostly with fused arches and ribs broken away, 9 dorsal and 2 caudal vertebrae, about 20 dorsal and cervical ribs, some portions of ventral ribs, portions of the acetabular region, of the pelvis with the constituent bones united, left femur, both tibiae and fibulae, tarsals, and 63 metapodial bones and phalanges.

 

= Muraenosaurus platyclis SEELEY, 1892
Etymology:
= Tremamesacleis platyclis (SEELEY, 1892) WHITE, 1940

Holotype: BMNH R2678

Locality: Peterborough, Cambridgeshire County, England, Southern United Kingdom.

Horizon: Oxford Clay.

Biostratigraphy:

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

Material: Skull, mandible, 38 cervical vertebrae, 21 dorsals, 14 caudals, numerous dorsal and caudal ribs, ?chevrons, shoulder girdle, humeri, radius, ulna and other bones of the paddle, pelvic girdle and femora.

Dorsal view of skull and dentary (ANDREWS, 1913).

Anterior portion of shoulder-girdle from above, posterior cervical vertebra and anterior cervical vertebra.

Referred material:

BMNH R2425: Posterior part of the right ramus of the mandible, a tooth, 9 cervical vertebrae, 2 dorsals, 5 caudals, numerous dorsal and ventral ribs, ?chevrons, humeri, right ilium, femora, tibia and fibula and numerous bones of the paddle.

BMNH R2426: 10 cervical vertebrae, 11 dorsals, and 14 caudals, mostly wanting the neural arches and much crushed and distorted, portions of the coracoids, and scapulae, an imperfect interclavicle with traces of the thin adherent clavicle, on one side, humeri, radii, ulnae, and other bones of the fore paddle, ilium, left femur, tibia, and fibula and other bones of the hind paddle.

 

= Cryptocleidus? vignalensis De La TORRE & CUERVO, 1949 (on a label)

Holotype:

Locality:

Horizon:

Biostratigraphy:

Age:

Material:

_____________________________________________________________________________________

Species: belcolis SEELEY, 1892
Etymology:
= Pirocleidus beloclis (SEELEY, 1892) ANDREWS, 1909

Holotype: BMNH R 1965

Locality: From an unspecified brick-pit near Peteroborourgh, Cambridgeshire County, England, Southern United Kingdom.

Horizon: Oxford Clay.

Biostratigraphy:

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

Material: Fragmentary dentrary, 6 cervical, 2 dorsal vertebrae, 10 ribs, scapulae, coracoids, interclavicle, humeri, 1 radius and ulnae.

1) Posterior portion of right mandible; 2) shoulder-girdle and proximal portion of left fore paddle; 3) Posterior cervical vertebra from right side; 4) Posterior cervical vertebra from front; 5) Cervical vertebrae; 6) Caudal vertebrae (ANDREWS, 1913).

Referred material:

BMNH R3698: Basioccipital, quadrate with part of squamosal, a much crushed exoccipital, portions of mandibular rami, atlas, axis, 30 cervical vertebrae, many with ribs and neural arches, 16 caudal vertebrae, numerous separate cervical and caudal ribs, ?chevrons, radius and ulna, femora, tibia and fibula.

 

= Picrocleidus sp ANDREWS 1910

Locality: Peterborough, Cambridgeshire County, England, Southern United Kingdom.

Horizon: Oxford Clay.

Biostratigraphy:

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

Material:

BMNH R2739: Basisphenoid, and parasphenoid, 26 cervical vertebrae mostly with the arches and ribs, 2 sacrals with the sacral ribs, 1 anterior caudal, some ventral ribs, both radii, odd paddle-bones, portions of ilia, ischia, and pubes.

BMNH R2429: 6 posterior cervical vertebrae, 2 pectorals, and the first dorsal, some dorsal ribs, the shoulder-girdle, wanting the interclavicle and posterior part of the coracoids, the left humerus.