Caelestiventus: a pterosaur from the Triassic desert

Caelestiventus hanseni was a pterosaur from a Late Triassic desert in what is now Utah. Its skull is preserved in three dimensions in sandstone, unlike the flattened bones that make up many early pterosaur fossils. It shows that pterosaurs had reached dry inland environments by the Triassic.

Evidence note

The type specimen records a partial skull and one wing-finger bone. Its wingspan is an estimate, and no stomach contents establish its diet.

Quick facts

Discovery and name

The fossil was found at Saints & Sinners Quarry in north-eastern Utah. Brooks Britt and colleagues described it in 2018. The genus name means “heavenly wind,” and the species name honours geologist Robin Hansen. The holotype, BYU 20707, includes portions of the skull and lower jaws together with a terminal phalanx from the wing finger.

The bones are embedded in hard sandstone and could not all be exposed mechanically. Computed tomography allowed researchers to reconstruct hidden surfaces and internal cavities as three-dimensional models. This method revealed anatomy that would otherwise remain buried inside the rock.

Head, teeth and size

The skull was large and high. Long, canine-like teeth occupied the front of the jaws, while smaller teeth with several cusps occurred farther back. This arrangement resembles that of Dimorphodon, but the skull features support a distinct genus.

Using skull proportions, the describing authors estimated a wingspan greater than 1.5 metres. The estimate is notable for a Triassic pterosaur, but the full wing is missing. It should not be treated as a directly measured adult wingspan.

Life in an inland desert

The Nugget Sandstone records an immense dune system. The pterosaur was buried in a small damp hollow between dunes where water and organic remains could collect. The fossil therefore extends the known settings used by early pterosaurs beyond lake and marine deposits.

Its teeth could have held small vertebrates, while the rear teeth may have processed harder food. Those are mechanical possibilities, not a demonstrated menu. No stomach contents have been found. The closest phylogenetic analysis grouped Caelestiventus with Dimorphodon in Dimorphodontidae. Other early pterosaurs show different combinations of primitive and specialised traits.

The pterosaur catalogue includes Caelestiventus as an important inland Triassic form. The sandstone establishes a desert-region setting, while the animal's precise activity, colour, and use of any oasis remain reconstructed.