Krzyzanowskisaurus
- Lived
- 237 to 206 million years ago, Late Triassic
- Diet
- Herbivore
- Group
- Early ornithischians
- Found in
- United States
- Named by
- Heckert 2005
Where its fossils were found
The evidence
Today
220 million years ago
Habitat
The Chinle rocks record rivers and floodplains in Late Triassic North America. Dinosaurs reported from these rocks include Coelophysis and Chindesaurus.
Field notes
About Krzyzanowskisaurus
What it was like
Krzyzanowskisaurus is known only from teeth. They were once thought to come from an early bird-hipped dinosaur, but similar teeth have turned out to belong to other reptiles, so it may not be a dinosaur.
Its world
It lived in the Late Triassic in what is now Arizona and New Mexico. Its teeth come from the Chinle Formation.
How it was found
Heckert named it in 2005. It honors a fossil collector.
Field gallery
More views of Krzyzanowskisaurus
Scenes reconstructed from the available fossil evidence.
Lived alongside
Found in the same rock formations
A rock formation can hold fossils laid down millions of years apart, so not every animal here met Krzyzanowskisaurus.
The evidence
The science behind Krzyzanowskisaurus
Which parts of the picture come from its own bones, and which come from its relatives.
From its own fossils
- Isolated teeth with serrated edges and a raised ridge around the base of the crown.
- Microscopic sections show thick enamel with lines marking its growth.
Borrowed from relatives
- Revueltosaurus offers a possible model for the missing body, with bony armor and a four-legged stance.
Still unknown
- Whether it was a dinosaur or a relative of crocodiles.
- The shape and size of its body.
- Which plants it ate.
Discovery timeline
- 2005Named itHeckert
- 2013How it fedHeckert & Miller-Camp
- 2021Family treeParker et al.
Key papers
The research behind what we know of Krzyzanowskisaurus
Named it
Separated the teeth into a new genus because of the raised ridge around the base of their crowns.
Krzyzanowskisaurus, a new name for a probable ornithischian dinosaur from the Upper Triassic Chinle Group, Arizona and New Mexico, USA. In A. B. Heckert & S. G. Lucas (eds.), Vertebrate Paleontology in Arizona. New Mexico Museum of Natural History and Science Bulletin 29: 77-83
No link available
How it fed
Found thick enamel and similar microscopic tooth structures in Krzyzanowskisaurus and Revueltosaurus, supporting a possible close relationship.
Tooth enamel microstructure of Revueltosaurus and Krzyzanowskisaurus (Reptilia:Archosauria) from the Upper Triassic Chinle Group, USA: Implications for function, growth, and phylogeny. Palaeontologia Electronica
Read the paper : Tooth enamel microstructure of Revueltosaurus and Krzyzanowskisaurus (Reptilia:Archosauria) from the Upper Triassic Chinle Group, USA: Implications for function, growth, and phylogeny (opens in a new tab)Family tree
Described the armored skeleton of Revueltosaurus and reviewed whether Krzyzanowskisaurus belongs in the same genus.
Osteology and relationships of Revueltosaurus callenderi (Archosauria: Suchia) from the Upper Triassic (Norian) Chinle Formation of Petrified Forest National Park, Arizona, United States. The Anatomical Record 305: 2353-2414
Read the paper : Osteology and relationships of Revueltosaurus callenderi (Archosauria: Suchia) from the Upper Triassic (Norian) Chinle Formation of Petrified Forest National Park, Arizona, United States (opens in a new tab)
Close relatives
Other members of Ornithischia
Sources: Wikidata