Pronunciation: kroh-MO-gee-SOR-us
Meaning: Painted Valley Lizard
Author/s: Ezcurra (2010)
Synonyms: None known
First Discovery: San Juan, Argentina
Discovery Chart Position: #734
Chromogisaurus novasi
Chromogisaurus and Panphagia were both discovered in the Ischigualasto Formation of San Juan and were described by two different authors nearly simultaneously. Some paleontologists wondered if the relevant notes had been compared or if two specimens of the same critter were being scrutinised, and the fact that the former was still mostly stuck in bone-obscuring matrix when it was heralded as an all new species did little to sooth their understandable scepticism.
With Chromogisaurus fully prepared for a more thorough description three years later, Ricardo N. MartÃnez realised that what had initially been identified as an ulna was actually a lower jawbone (possibly of the rhynchosaur, Scaphonyx), a metatarsal was in fact a chevron, and an ischium probably wasn't. But as much by luck as by judgement, Chromogisaurus proved to be a valid, stand-alone genus that brought the total number of Ischigualasto Formation dinosaurs to five, and three of those are basal sauropodomorphs.
Behind Pamphagia and Eoraptor (which was described a decade earlier as a theropod, and may yet turn out to be one), Chromogisaurus was the area's third named sauropodomorph, but its more immediate family — Guabasauridae — seems to be on the verge of collapse. Like Eoraptor, the group anchor Guaibasaurus was initially identified as a theropod and probably is, and the other guaibasaurids, including Chromogisaurus, may just be a ragtag bunch of troublesome omnivores that aren't closely related at all.
With Chromogisaurus fully prepared for a more thorough description three years later, Ricardo N. MartÃnez realised that what had initially been identified as an ulna was actually a lower jawbone (possibly of the rhynchosaur, Scaphonyx), a metatarsal was in fact a chevron, and an ischium probably wasn't. But as much by luck as by judgement, Chromogisaurus proved to be a valid, stand-alone genus that brought the total number of Ischigualasto Formation dinosaurs to five, and three of those are basal sauropodomorphs.
Behind Pamphagia and Eoraptor (which was described a decade earlier as a theropod, and may yet turn out to be one), Chromogisaurus was the area's third named sauropodomorph, but its more immediate family — Guabasauridae — seems to be on the verge of collapse. Like Eoraptor, the group anchor Guaibasaurus was initially identified as a theropod and probably is, and the other guaibasaurids, including Chromogisaurus, may just be a ragtag bunch of troublesome omnivores that aren't closely related at all.
(Novas's Painted Valley Lizard)Etymology
Chromogisaurus is derived from the Greek "chroma" (color) and "gi" (ground or land) in reference to the Painted Valley (Valle Pintado) where the specimen was collected, and "sauros" (lizard). The species epithet, novasi, honors Argentine paleontologist Fernando Emilio Novas.
Discovery
The remains of Chromogisaurus were discovered at "Valle Pintado" in the Cancha de Bochas Member of the Ischigualasto Formation (Agua de la Peña Group, Ischigualasto-Villa Unión Basin), Ischigualasto Provincial Park, San Juan Province, Argentina, in the autumn of 1988 during a joint field trip carried out by the Museo Argentino
de Ciencias Naturales ‘Bernardino Rivadavia’, the Univer-
sidad Nacional y Museo de San Juan and the University
of Chicago.
The holotype (PVSJ 846) consists of bits of the front and hind limbs, the pelvis and two caudal (tail) vertebrae.
