Genus: Ianthasaurus REISZ & BERMAN, 1985
Etymology: Ianth refers to the Iantha River, Anderson County, Kansas, and Greek, sauros, "lizard."

Species: mirabilis (FRITSCH, 1895)
Etymology:
= Naosaurus mirabilis FRITISCH, 1895
= Edaphosaurus mirabilis (FRITSCH, 1895) ROMER & PRICE, 1940

Holotype: Prague Museum.

Locality: Kuonova, Czech Republic.

Horizon: Upper Stephanian.

Biostratigraphy:

Age: Upper Silesian, upper Kasimovian to Gzelian Epoch, Latest Carboniferous (Latest Pennsylvanian).

Material: Fragmentary vertebra.


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Species: credneri (JAEKEL, 1910)
Etymology:
= Naosaurus credneri JAEKEL, 1910
= Edaphosaurus credneri (JAEKEL, 1910) ROMER & PRICE, 1940

Holotype: Museum of the Geologische Landesanstalt, Leipzig

Locality: Nieder-Haáßálich Plauenschen Grunde near Dresden, Saschen State, Germany.

Horizon:

Biostratigraphy:

Age: Wolfcampanian stage, Middle Rotliegendes Epoch, Early Permian.

Material: Fragmentary skeleton.


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Species: hardestii REISZ & BERMAN, 1986
Etymology:

Holotype: KUVP 69035

Locality: NW 1/4, sec. 5, tp. 19E, Putnam Township, near Garnett, Anderson County, Kansas.

Horizon: Rock Lake Shale Member of the Stanton Formation, Lansing Group, Missourian Series.

Biostratigraphy:

Age: Late Pennsylvanian (Late Carboniferous).

Material: Several disarticulated skull-roof elements of the right side of the skull, posterior 2/3rds of the lower right jaw, a nearly complete series of articulated presacral vertebrae, several disarticulated dorsal ribs, and a humerus.

Referred material:

ROM 29940: 1st sacral rib, 7 caudal ribs, and a partial dorsal neural arch with a fragmented but complete neural spine.

ROM 29941: A cervical vertebra, a dorsal vertebra with associated rib, and a lumbar vertebra with an attached rib.

ROM 29942: Disarticulated and crushed elements of the skull consisting of the maxillae, left jugal, postfrontals, postorbital, and anterior coronoid, as well as elements of the postcranial skeleton consisting of neural arches and spines, 3 dorsal and a caudal cenra, an intercentrum, presacral ribs, a caudal rib, right scapula and anterior coracoid, nearly complete left pelvis, femur and manus..

MODESTO & REISZ, 1990

ROM 37751: Semi articulated skull roof, left angular, both ilia, left pubis, left ischium, 23 presacral vertebrae, several caudal vertebrae, and dorsal and caudal ribs.

MAZIERSKI & REISZ, 2006, 2010

ROM 59933: Left maxilla, left quadrate, left postorbital, left pterygoid, anterior portion of left mandibular ramus, 7 whole or partial presacral vertebrae, 4 whole or partial caudal vertebrae with 2 hemal arches, 8 ribs, and 7 phalanges.