Dinosaur VaultEvery known dinosaur
Ptychotherates, Late TriassicChinle Formation, New Mexico · named 2026
See more pictures

Ptychotherates

"fold hunter"

Type species Ptychotherates bucculentus

Lived
206 to 201 million years ago, Late Triassic
Group
Early dinosaurs
Found in
United States
Named by
Srivastava and Nesbitt 2026

Where its fossils were found

The evidence

Today

1 find

200 million years ago

Map: C. R. Scotese, PALEOMAP

Habitat

It lived on a river plain in what is now New Mexico. Coelophysis and Daemonosaurus occur in the same fossil quarry.

Field notes

About Ptychotherates

What it was like

Ptychotherates was a small, early saurischian dinosaur known from part of a skull. The bone under its eye was unusually deep, which gave its face a tall cheek.

Its world

It lived near the end of the Triassic, in what is now New Mexico. It comes from the Chinle Formation, where it lived beside the early theropod Coelophysis and the buck-toothed Daemonosaurus.

How it was found

Srivastava and Nesbitt named Ptychotherates in 2026. The type species is Ptychotherates bucculentus.

Field gallery

More views of Ptychotherates

Scenes reconstructed from the available fossil evidence.

Ptychotherates in its habitat, photo 1

1 of 2

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 Ptychotherates.

The evidence

The science behind Ptychotherates

Which parts of the picture come from its own bones, and which come from its relatives.

From its own fossils

  • A single partial skull, distorted after burial, preserves much of the braincase, skull roof and jaws. No body bones have been linked to it.
  • The cheekbone below the eye is exceptionally tall and flat from side to side. The upper surfaces of its nose and forehead bones are flat, and a ledge of bone overhangs the eye socket.
  • Its teeth curve backward and have finely serrated edges.

Borrowed from relatives

  • The missing tip of the snout, neck and body can be modeled on Tawa, a close relative with a much more complete skeleton.

Still unknown

  • The front of its snout. The tip of the upper jaw and the front of the nose and forehead bones are missing, so the length of its head is not known.
  • Its body size and limb proportions.
  • Exactly where its branch fits among the earliest dinosaur groups.

Discovery timeline

  1. 2009Close relativeNesbitt et al.
  2. 2019Close relativeMarsh et al.
  3. 2020Same rocksNesbitt & Sues
  4. 2026Named itSrivastava & Nesbitt

Key papers

The research behind what we know of Ptychotherates

Sources: Wikidata