Protitanotherium

Protitanotherium Temporal range: Middle Eocene PreꞒ Ꞓ O S D C P T J K Pg N
Protitanotherium emarginatum
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	Perissodactyla
Family:	†Brontotheriidae
Genus:	†Protitanotherium Hatcher, 1895
Species:	†P. emarginatum
Binomial name
†Protitanotherium emarginatum Hatcher, 1895
Synonyms[1]
Diplacodon emarginatum Hatcher, 1895 Protitanotherium superbum Osborn, 1908 Sthenodectes australis Wilson, 1977

Protitanotherium is a genus of brontotheres native to North America during the middle Eocene. It contains one species, P. emarginatum, described in 1895 by the American paleontologist John Bell Hatcher.[1]

Discovery and naming

In 1895, John Bell Hatcher described a partial cranial material from the Uinta Formation of Utah, YPM-PU 11242, as the holotype of a new species of brontothere. He tentatively included the taxon as a species of Diplacodon (D. emarginatum), but he noted that "should future discoveries show that there are hornless forms with same dental characters as Diplacodon", it would require a new genus name Protitanotherium.[2]

In a strict sense, Protitanotherium emarginatum is restricted to the type specimen,[3] though other authors have referred other specimens to this species.[1] The genus name is a portmanteau of the Latin word meaning "before" (pro) and Ancient Greek words meaning "giant" (titan) and "beast" (therion).[4] It was later accepted for use by other authors including Osborn (1908) who named a putative second species P. superbum (AMNH 2501) from the same locality, but this species was later suggested to be synonymous with P. emarginatum.[1]

It was once claimed that Sthenodectes australis (TMM 41723-3) described by Wilson (1977) from the Pruett Formation of Texas and some skull specimens from other formations (Uinta Formation, Wiggins Formation and Devil's Graveyard Formation) might represent a single taxon similar to P. emarginatum,[3] but Mihlbachler suggested that Sthenodectes australis is synonymous with P. emarginatum and redescribed the Wiggins Formation specimen (AMNH 117163), previously referred to as cf. Protitanotherium, as the holotype of Diplacodon gigan.[1][5] Fragmentary brontothere specimens from the middle to late Eocene strata of North Korea were named as P. koreanicum by Takai (1939), but this species is now considered as a nomen dubium.[1]

References

1. Mihlbachler, Matthew C. (June 2008). "Species Taxonomy, Phylogeny, and Biogeography of the Brontotheriidae (Mammalia: Perissodactyla)". Bulletin of the American Museum of Natural History. 2008 (311): 1–475. doi:10.1206/0003-0090(2008)501[1:STPABO]2.0.CO;2. ISSN 0003-0090.
2. Hatcher, J.B. (1895). "On a new species of Diplacodon, with a discussion of the relations of that genus to Telmatotherium". American Naturalist. 29: 1084–1090.
3. Mader, B.J. (2008). "A species level revision of Bridgerian and Uintan brontotheres (Mammalia, Perissodactyla) exclusive of Palaeosyops". Zootaxa. 1837 (30): 1–85. doi:10.11646/zootaxa.1837.1.1.
4. "Glossary. American Museum of Natural History". Archived from the original on 20 November 2021.
5. Mihlbachler, Matthew C. (2011). "A new uintan horned brontothere from Wyoming and the evolution of canine size and sexual dimorphism in the Brontotheriidae (Perissodactyla: Mammalia)". Journal of Vertebrate Paleontology. 31 (1): 202–214. Bibcode:2011JVPal..31..202M. doi:10.1080/02724634.2011.539653. S2CID 84879982.