Genus: Baptanodon MARSH, 1880
Etymology: Greek, bapto, “dive” and Greek, anodon, “toothless”: Toothless diver.
= Apatodonosaurus MEHL, 1928
Etymology: Greek, apatao, “deceive”, Greek, odont- (odous), “tooth”, and Greek, sauros, “lizard”: Deceptive toothed lizard.
= Microdontosaurus GILMORE, 1902
Etymology: Greek, mikros, “small”, Greek, odont- (odon), “tooth”, and Greek, sauros, “lizard”: Small toothed lizard.
= Sauranodon MARSH, 1879 non JOURDAN, 1862 (Sauranodon incisivus Sphenodontia, Saphenosauridae)
Etymology: Greek, sauros, “lizard”, Greek, an “no, without” and Greek, odon, “tooth”: Toothless lizard.

Species: natans (MARSH, 1879) LYDEKKER, 1889
Etymology:
= Sauranodon natans MARSH, 1879
= Ophthalmosaurus natans (MARSH, 1879) HUENE, 1922

Holotype: No. 1952

Locality: Vicinity of Como Bluff, Albany County, Wyoming.

Horizon: Sundance Formation.

Biostratigraphy:

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

Material: Fragmentary skull and fragmentary skeleton.

Referred material:

GILMORE, 1905

Locality: Freeze Out Mountains, in Carbon County, Wyoming.

Horizon: Sundance Formation (Sauranodon beds, Baptanodon Beds.)

Biostratigraphy:

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

Material:

No. 1441: Skull and fragmentary skeleton.

Note: Has skull damage that indicates nosediving into soft sediment, WAHL, 2009

 

MASSARE, BUCHHOLTZ, KENNEY & CHOMAT, 2006

Locality: UW locality VP- 2005-007 Alcova Reservoir area, Natrona County, Wyoming.

Horizon: Sundance Formation.

Biostratigraphy:

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

Material:

UW 34786: 44 articulated vertebrae from the posterior dorsal region to just posterior to the tail bend, a few isolated fluke vertebrae were also collected.

 

MASSARE & WAHL, 2008

Locality: Natron County, Wyoming.

Horizon: Upper Redwater Shale, Sundance Formation.

Biostratigraphy:

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

Material:

UW 24216: Skull.

MASSARE, & YOUNG, 2005
= Baptanodon MASSARE & YOUNG, 2003

Locality: Redwall area, University of Wyoming location VP 2002-02, Northwestern Natrona County, Wyoming.

Horizon: Lower Redwater Shale, Sundance Formation.

Biostratigraphy: Camptonectes zone.

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

Material: A string of 10 articulated vertebrae and at least as many disarticulated ones, along with many disarticulated ribs, parts of two limbs, one partially articulated, and as yet unidentified bone.
Note: Stomach contacts with badly fragmented coleoid cephalopod hooklets.

 

WAHL, 2009

Locality: Natrona County, Wyoming.

Horizon: Sundance Formation.

Biostratigraphy: Camptonectes zone.

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

Material:

UW 24816: Skull and fragmentary skeleton.

Note: Specimen shows pathology due to sever nose dive into soft sediment. The tip of the snout is bent and has other taphonomy that shows this is what happened.

  Note: Ichnotaxon penetrative borings unattriubted epibionts JAMISON-TODD, UPCHURCH & MANNION, 2023.

= Sauranodon discus MARSH, 1880
= Baptanodon discus (MARSH, 1880) MARSH, 1880
= Ophthalmosaurus discus (MARSH, 1880) KUHN, 1934
Etymology:

Holotype: No. 1955

Locality: Wyoming.

Horizon: Sundance Formation (Sauranodon beds, Baptanodon Beds.)

Biostratigraphy:

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

Material: Skull and fragmentary skeleton.

Referred material:

No. 878: Skull and fragmentary skeleton.

Note: Has skull damage that indicates nosediving into soft sediment, WAHL, 2009

No. 603: Skull.

Note: Has skull damage that indicates nosediving into soft sediment, WAHL, 2009

 

= Microdontosaurus petersonsii GILMORE, 1902
Etymology:

Holotype:

Locality:

Horizon: Sundance Formation (Sauranodon beds, Baptanodon Beds.)

Biostratigraphy:

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

Material:

= Baptanodon marshi KNIGHT, 1903
= Ophthalmosaurus marshi (KNIGHT, 1903) KUHN, 1934
Etymology: In honor of O. C. Marsh.

Holotype: "S"

Locality: Northern part of Albany County, Wyoming.

Horizon: Sundance Formation (Sauranodon beds, Baptanodon Beds.)

Biostratigraphy:

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

Material: Fragmentary skeleton.

 

= Baptanodon robustus GILMORE, 1906
Etymology: Latin, robustus, "robust, strong."
= Ophthalmosaurus robustus (GILMORE, 1906) KUHN, 1934

Holotype: No. 919

Locality: Red Fork of Powder River, Big Horn County, Wyoming.

Horizon: Sundance Formation (Sauranodon beds, Baptanodon Beds.)

Biostratigraphy:

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

Material: Well-preserved pectoral girdle, 10 cervical vertebrae.

= Baptanodon reedi GILMORE, 1907
Etymology:
= Ophthalmosaurus reedi (GILMORE, 1907) KUHN, 1934

Holotype:

Locality: Dawson Creek Basin, Fremont County, Wyoming.

Horizon: Sundance Formation (Sauranodon beds, Baptanodon Beds.)

Biostratigraphy:

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

Material: 1 half of the skull divided longitudinally, 153 vertebrae, ribs, proximal part of the left scapula, both humeri, and the proximal portion of the left pectoral extremity.

 

= Apatodonosaurus grayi MEHL, 1928
Etymology:

Holotype: University of Missouri Vertebrate Paleontology No. 503

Locality: Sundance, Fremont County, Wyoming.

Horizon: Sundance Formation.

Biostratigraphy:

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

Material: Fragmentary skull and fragmentary skeleton

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