Triassic tuatara ancestor reptiles, new research

This 5 February 2018 video from England says about itself:

New small reptile species that lived 205 million years ago discovered in a quarry in South Wales

Fossils discovered in a quarry in South Wales have been identified as a new small species of reptile that lived 205 million years ago. The species has been called Clevosaurus cambrica, the second part is Latin and refers to the fact that it comes from Wales.

They belong to a new species of Clevosaurus (Gloucester lizard), named in 1939 after Clevum, the Latin name of Gloucester.

The new species, Clevosaurus cambrica lived side by side with a small dinosaur, Pantydraco, and a crocodile-like animal, Terrestrisuchus.

We compared it with other examples of Clevosaurus from places around Bristol and South Gloucestershire, but our new beast is quite different in the arrangement of its teeth. In the Late Triassic period, the foothills of south Wales and southwest England formed an archipelago that was inhabited by small dinosaurs and relatives of the tuatara, a reptilian ‘living fossil’ from New Zealand. The limestone quarries of the region have many caves or fissures that contain sediments filled with bones of small species of reptiles that collapsed at the feet of dinosaurs.

From the University of Bristol in England:

Skulls of 2 species of ancient reptile reconstructed

February 25, 2019

Using two partially fragmented fossil skulls, a student at the University of Bristol has digitally reconstructed, in three-dimensions, the skulls of two species of ancient reptile that lived in the Late Triassic, one of which had been previously known only from its jaws.

The research was completed by Sofia Chambi-Trowell, an undergraduate in Bristol’s School of Earth Sciences, as part of her final-year project for her degree in Palaeobiology.

Clevosaurus was a lizard-like reptile that was first named back in 1939 from specimens found at Cromhall Quarry, near Bristol.

Since then, similar beasts have been found elsewhere around Bristol and in South Wales, as well as in China and North America. Clevosaurus was an early representative of an ancient group of reptiles called Rhynchocephalia, which today is represent only by the tuatara of New Zealand.

In her project, Sofia worked on new fossils of Clevosaurus hudsoni, the first species to be named, and Clevosaurus cambrica, which was named from a quarry site in South Wales in 2018.

She used CT scans of both skulls to reconstruct their original appearance, and she found evidence that the two species, which lived at the same time in the Late Triassic, some 205 million years ago, showed significant differences.

Sofia said: “I found that Clevosaurus cambrica was smaller overall and had a narrower snout than Clevosaurus hudsoni.

“Other differences include the number, shape and size of the teeth in the jaws, suggesting the two species fed on different food.”

Clevosaurus probably ate insects. Clevosaurus cambrica has corkscrew-shaped teeth which suggests it was able to shred the insect carcass by the natural twist as it drove its teeth through the hard carapace.

Clevosaurus hudsoni had teeth more adapted for simply slicing the prey. This might suggest that Clevosaurus cambrica ate larger or harder-shelled insects like beetles or cockroaches, while Clevosaurus hudsoni ate worms or millipedes which were less tough.

Professor Mike Benton, one of Sofia’s project supervisors, added: “Sofia’s work is a great example of how modern technology like CT scanning can open up information we would not know about.

“It took a lot of work, but Sofia has uncovered a good explanation of how many species of Clevosaurus could live side by side without competing over food.”

Her other supervisor, Dr David Whiteside, said: “Two hundred million years ago, Bristol lay much further south than it does today — about the same latitude as Morocco.

“Also, sea level was higher, so the peaks of limestone hills south of Bristol and in South Wales were islands, like Florida today [?].

“They were full of dinosaurs, early mammals, and rhynchocephalians feeding on the rich, tropical plants and insects. Sofia’s work helps us understand so much about this extraordinary time when dinosaurs were just taking over the world.”

This November 2017 video from England says about itself:

Computed tomography derived surface models of a left hind limb of Clevosaurus hudsoni

Sample: partially complete, left hind limb of Clevosaurus hudsoni (NMHUK PV R36846)

Sample composition: Fossilised bone

Facility: µ-VIS X-Ray Imaging Centre, Southampton

Researchers: Aileen O’Brien (University of Southampton), David I. Whiteside (University of Bristol),John E. A. Marshall (University of Southampton)

µ-CT images of a partially complete, left hind limb of Clevosaurus hudsoni (NMHUK PV R36846) were obtained at µ-VIS X-Ray Imaging Centre, Southampton and the data processed using Avizo 3D visualisation software, in the µ-VIS visualisation suite. The surface models created from the µ-CT scans provide a more complete picture of the morphology of the hind limb, including non-visible parts of the bones concealed within the matrix. Features of the bones such as compression in a particular plane, grooves, processes, facets and projections are often disguised by matrix, or are hidden by adjacent bones. Surface modelling of µ-CT data has highlighted these characters and yielded insights into the ontogeny and age of the animal from which the specimen came.

The authors would like to thank Sandra Chapman (NHMUK) for arranging the loan of Clevosaurus hudsoni.