Pronunciation: plan-i-KOHK-suh
Meaning: Flat hip
Author/s: DiCroce and Carpenter (2001)
Synonyms: None known
First Discovery: Utah, USA
Discovery Chart Position: #485
Planicoxa venenica
Planicoxa venenica is a wide-load iguanodont known from an odd "flat" hip bone (dorso-ventrally depressed ilium, to boffins) and other bits and bobs that were found in Utah's Cedar Mountain Formation: an area rich in remnants of ornithopods, theropods and sauropods, some of which were discovered alongside mammals, turtles and fish.
The area has its fair share of other iguanodonts too, including Cedarosaurus crichtoni which was described in 2007 and almost immediately pegged as a potential synonym of Planicoxa venenica by suspicious palaeontologists. Both are known from sparse, fragmentary fossils and the most significant difference seems to be their size. Although lacking in compareable parts, they were found at different depths that were separated by at least seven million years so the chances of their size difference being growth related, that is: they represent an adult and juvenile of the same species, are rather slim.
The area has its fair share of other iguanodonts too, including Cedarosaurus crichtoni which was described in 2007 and almost immediately pegged as a potential synonym of Planicoxa venenica by suspicious palaeontologists. Both are known from sparse, fragmentary fossils and the most significant difference seems to be their size. Although lacking in compareable parts, they were found at different depths that were separated by at least seven million years so the chances of their size difference being growth related, that is: they represent an adult and juvenile of the same species, are rather slim.
(Flat hip from the Poison Strip)Etymology
Planicoxa is derived from the Latin "planus" (flat, level) and "coxa" (hip), named for the flat appearance of its ilium (a hip bone).The species epithet, venenica, is Latin for "poison", and refers to the Poison Strip Sandstone Member of the Cedar Mountain Formation where it was discovered.
Discovery
The remains of Planicoxa venenica were discovered at "Tony's Bone Bed" in the Poison Strip Member of the Cedar Mountain Formation, Grand County, Utah.
The holotype (DMNH 42504, housed at the Denver Museum of Natural History) is a well-preserved hip bone, some limb material and vertebrae.
