Pronunciation: proh-tog-NAY-tho-SOR-us
Meaning: First jaw lizard
Author/s: Olshevsky (1991)
Synonyms: Protognathus oxyodon
First Discovery: Sichuan, China
Discovery Chart Position: #365
Protognathosaurus oxyodon
Protognathosaurus is a sauropodomorph of uncertain affinity from the Middle Jurassic of Sichuan, that Yihong Zhang formerly named Protognathus when he described its embarrassingly meagre fossils in 1988.
Unfortunately, Basilewsky chose that name too—for a genus of beetle—and he chose it 38 years earlier. So, by the ironclad laws of priority, the beetle wins, despite being orders of magnitude smaller. Such is science.
Spotting the homonymy (sameness of name), George Olshevsky proposed Protognathosaurus as a replacement in 1991. Yet some experts suspect that its remains—an entire piece of tooth-bearing lower jaw—may belong to a previously named sauropod, or perhaps a "prosauropod", and quietly wonder if it was worth the bother.
By the by, Protognathosaurus and Protognathus have nothing to do with Protomognathus, a type of ant, or Protognathinus spielbergi, a scarab beetle that was named in honour of Steven Spielberg by Halumeau and Brochier in 2001. Nor does the Protognathosaurus jaw—with its downward curve, pointed teeth, and unusually high tooth count—have much in common with any currently known sauropod dinosaur.
Spotting the homonymy (sameness of name), George Olshevsky proposed Protognathosaurus as a replacement in 1991. Yet some experts suspect that its remains—an entire piece of tooth-bearing lower jaw—may belong to a previously named sauropod, or perhaps a "prosauropod", and quietly wonder if it was worth the bother.
By the by, Protognathosaurus and Protognathus have nothing to do with Protomognathus, a type of ant, or Protognathinus spielbergi, a scarab beetle that was named in honour of Steven Spielberg by Halumeau and Brochier in 2001. Nor does the Protognathosaurus jaw—with its downward curve, pointed teeth, and unusually high tooth count—have much in common with any currently known sauropod dinosaur.
(Sharp-Toothed First-Jaw lizard)Etymology
Protognathosaurus is derived from Greek "protos" (first), "gnathos" (jaw) and "sauros" (lizard). (The first jaw lizard's first name was Protognathus). The species epithet, oxyodon, combines the Greek "oxy" (sharp) and the Greek "odon" (tooth), referring to a few sharp teeth that were present in the only known fossil.
Discovery
The remains of Protognathosaurus were discovered in the Lower Shaximiao (Xiashaximiao) Formation at Dashanpu Dinosaur Quarry, near Zigong, Hechuan County, Sichuan Province, China. The holotype (CHG CV 00732) is a partial, tooth-bearing bone of the lower jaw, sporting eighteen sockets, some containing sharp replacement teeth.
