Organism · Reptiles including birds
Glyptops ornatus
Source time context (not species duration) · ≈ 201–143 Ma
Inferred life reconstruction
Glyptops ornatus
Overview
Glyptops ornatus was a Jurassic turtle whose skull, carapace, and parts of the postcranial skeleton can be compared together. Fine details of the lower jaw became the subject of new research. CT offered a view into the story of the head within the shell.[1]
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Key facts
A 2024 study used high-resolution CT to examine the lower jaw bones of an old fossil individually. Their articulation with the skull had previously made detailed description difficult. Seeing existing fossils through new methods matters as much as finding new ones.[1]
Time and place
AMNH 336 came from the Morrison Formation at Bone Cabin Quarry in present-day Wyoming, United States. It is described as Tithonian material of the Late Jurassic. The Jurassic as a whole spans approximately 200–140 million years ago.[1][3]
The time range describes source context, not the complete duration of this species.
Size, form and skeleton
AMNH 336 associates a skull, lower jaw, carapace, and partial skeleton. The lower jaw is described as slender and low, with a very narrow food-processing surface. Observation can move from the large carapace outline to smaller jaw structures.[1]
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Habitat and reproduction
In 2024, researchers proposed the possibility of active predation based on lower jaw structure. The study treats it as a Jurassic aquatic turtle. Jaws directly used in feeding convey clues to life different from those of the shell.[1]
Fossil discovery
This specimen was studied in detail as Glyptops plicatulus in 1979. A 2024 study treated it as ornatus following later taxonomic revision. Both the name and methods used to study the same fossil changed.[1]
References
- Evers (2024) — The mandible and feeding of Glyptops
- Lucas, Rinehart & Heckert (2006), Glyptops (Testudines, Pleurosternidae) from the Upper Jurassic Morrison Formation, New Mexico
- International Commission on Stratigraphy (2024) — Geological time chart
- Evers (2024) — The mandible and feeding of Glyptops
- International Commission on Stratigraphy (2024) — Geological time chart
- Study of Camarasaurus distribution in the Morrison Formation and geological age
- International Commission on Stratigraphy (2024) — Geological time chart
Research questions
Why are specimens preserving a turtle’s skull and carapace together useful? Some fossils preserve only a head, others only a shell, making comparison difficult. Material connecting both provides clues linking form and relationships.[1]
Observation
Move your gaze from the broad carapace outline to the head and lower jaw. The conspicuous shell and small food-processing jaws tell different stories of the same turtle.[1][2]
Related organisms
Camarasaurus grandisDinosaursSource time context (not species duration) · ≈ 201–143 MaA turtle and sauropod of the Morrison Formation
Read Glyptops alongside Camarasaurus from the Late Jurassic Morrison Formation. Glyptops specimen AMNH 336 came from Bone Cabin Quarry in present-day Wyoming, United States. Turtle research and sauropod neck and trunk bones can be compared as different sources of evidence.