1903 in paleontology explained

Archosauromorphs

Newly named dinosaurs

Data courtesy of George Olshevsky's dinosaur genera list.^[1]

Name	Novelty	Status	Authors	Age	Unit	Location	Notes	Images
Brachiosaurus^[2]	gen et sp	Valid	Riggs	Late Jurassic	Morrison Formation, Colorado
Haplocanthosaurus^[3]	gen et sp	Valid; nomen conservandum	Hatcher	Late Jurassic	Morrison Formation, Colorado	(and)	New name for "Haplocanthus", mistakenly thought preoccupied
"Haplocanthus"^[4]	gen et sp	Nomen oblitum	Hatcher	Late Jurassic	Morrison Formation, Colorado		Erroneously thought preoccupied by Haplacanthus Agassiz, 1945 and renamed Haplocanthosaurus.
Ornitholestes^[5]	gen et sp	Valid	Osborn	Kimmeridgian	Morrison Formation, Wyoming		Known from a single skull and partial skeleton.
Telmatosaurus^[6]	gen	Valid	Nopcsa	Maastrichtian	Sânpetru Formation, Transylvania		new genus for Limnosaurus Nopcsa, 1899.

Sauropterygians

• Plesiosaur gastroliths documented.^[7]

Newly named plesiosaurs

Name	Novelty	Status	Authors	Age	Unit	Location	Notes	Images
Apatomerus	gen et sp	Valid	Williston	Albian	Kiowa Shale, Kansas		first described as a pterosaur; reidentified in the 1970s
Brachauchenius	gen et sp	Valid	Williston	Turonian	Greenhorn Formation,	(and)	A brachauchenine pliosaurid.
Dolichorhynchops	gen et sp	Valid	Williston	Turonian	Smoky Hill Chalk, Kansas	(and) (and)	A polycotylid.

Synapsids

Non-mammalian

Name	Novelty	Status	Authors	Age	Unit	Location	Notes	Images
Lycosuchus	gen et sp	Valid	Broom	Middle Permian	Middle Abrahamskraal Formation
Scylacosaurus	gen et sp	Valid	Broom	Late Permian	Cistecephalus Assemblage Zone
Scymnosaurus	gen et sp	Valid	Broom	Middle Permian	Middle Abrahamskraal Formation

Eutherians

Cetaceans

Pholidotes

References

1. Web site: Olshevsky . George . Dinogeorge's Dinosaur Genera List . 2008-08-07 . 2011-07-15 . https://web.archive.org/web/20110715102453/http://www.polychora.com/dinolist.html . dead .
2. Riggs, E.S. 1903. Brachiosaurus altithorax, the largest known dinosaurs. Amer. J. Science 15 (4):pp. 299-306.
3. Hatcher, J.B. 1903. Osteology of Haptocanthosaurus. with description of a new species, and remarks on the probable habits of the Sauropoda and the age and origin of the Atlantosaurus beds. Mem. Carnegie Mus. 2: pp. 1-72.
4. Hatcher, J.B. 1903. A new name for the Dinosaur Haplocanthus Hatcher. Proceedings of the Biological Society of Washington 16: p.100.
5. Osborn, H. F. 1903. Ornitholestes hermanni, a new compsognathoid dinosaur from the Upper Jurassic. Bull. Amer. Mus. Nat. Hist. 19: pp. 459-464.
6. Nopcsa, F. 1903. Telmatosaurus, new name for the dinosaur Limnosaurus. Geol. Mag. (ser. 4) 10:pp. 94-95.
7. Williston (1903). Sanders, Manley, and Carpenter (2001), "Table 12.1" page 167.

• Sanders F, Manley K, Carpenter K. Gastroliths from the Lower Cretaceous sauropod Cedarosaurus weiskopfae. In: Tanke D.H, Carpenter K, editors. Mesozoic vertebrate life: new research inspired by the paleontology of Philip J. Currie. Indiana University Press; Bloomington, IN: 2001. pp. 166–180.
• Williston, Samuel Wendel; 1903. North American Plesiosaurs; Field Columbian Museum Publication 73, Geological Series; II(I); Field Columbian Museum, Chicago.