Fossils continue to reveal more about the amazing bountiful variety of species which once inhabited the Earth millions of years before humans emerged. In this article we share two of the most recent pieces of fossil research taking us from Scotland to Australia.
Ceoptera evansae, Skye, Scotland
In Skye, Scotland a new species of pterosaur has been discovered by scientists from the Natural History Museum, University of Bristol, University of Leicester, and University of Liverpool.
The remains consist of a partial skeleton of a single individual, including parts of the shoulders, wings, legs and backbone. Many of the bones remain completely embedded in rock and can only be studied using CT-scanning.
Professor Paul Barrett, Merit Researcher at the Natural History Museum explained:
“Ceoptera helps to narrow down the timing of several major events in the evolution of flying reptiles. Its appearance in the Middle Jurassic of the UK was a complete surprise, as most of its close relatives are from China. It shows that the advanced group of flying reptiles to which it belongs appeared earlier than we thought and quickly gained an almost worldwide distribution.”
Prof. Barrett and his colleagues described the new species, naming it Ceoptera evansae: Ceoptera from the Scottish gaelic word Cheò, meaning mist (a reference to the common gaelic name for the Isle of Skye Eilean a’ Cheò, or Isle of Mist), and the Latin -ptera, meaning wing. Evansae honours Professor Susan E. Evans, for her years of anatomical and palaeontological research, in particular on the Isle of Skye.
Lead author Dr Liz Martin-Silverstone, a palaeobiologist from the University of Bristol, said:
“The time period that Ceoptera is from is one of the most important periods of pterosaur evolution, and is also one in which we have some of the fewest specimens, indicating its significance. To find that there were more bones embedded within the rock, some of which were integral in identifying what kind of pterosaur Ceoptera is, made this an even better find than initially thought. It brings us one step closer to understanding where and when the more advanced pterosaurs evolved.”
Click on this link to access A new pterosaur from the Middle Jurassic of Skye, Scotland and the early diversification of flying reptiles is published in the Journal of Vertebrate Paleontology.
Harajicadectes zhumini, Alice Springs, Australia
In Australia A newly described fossil fish discovered in remote fossil fields west of Alice Springs has been named Harajicadectes zhumini by an international team of researchers led by Flinders University palaeontologist Dr Brian Choo.
The fossil was named for the Harajica Sandstone Member where the fossils were found in Australia’s ‘Red Centre’ and the ancient Greek dēktēs (“biter”). It also pays homage to Professor Min Zhu, currently at the Chinese Academy of Sciences, Beijing, who has made some major contributions to the research of early vertebrates.
One of the ancient Tetrapodomorph lineage, some of which became ancestors of limbed tetrapods – and later humans – Harajicadectes is particularly distinctive for its large openings on the top of their skull.
“These spiracular structures are thought to facilitate surface air-breathing, with modern-day African bichir fish having similar structures for taking in air at the water’s surface,” explained Flinders Palaeontology Lab researcher Dr Brian Choo, who studied the most complete specimen of the newly described Harajicadectes which grew to about 40cm.
“This feature appears in multiple Tetrapomodorph lineages at about the same time during the Middle-Late Devonian.
“In addition to Harajicadectes from central Australia, large spiracles also appeared in Gogonasus from Western Australia and elpistostegalians like Tiktaalik (the closest relatives to limbed tetrapods). Plus it also appears in the unrelated Pickeringius a ray-finned fish from Western Australia, first described in 2018.”
Flinders Professor John Long, a leading Australian expert of fossil fish said that the synchronised appearance of this air-breathing adaptation may have coincided with a time of decreased atmospheric oxygen during the mid-Devonian.
“The ability to supplement gill respiration with aerial oxygen likely afforded an adaptive advantage,” says Professor Long.
“We found this new form of lobe-finned fish in one of the most remote fossil sites in all of Australia, the Harajica Sandstone Member in the Northern Territory, almost 200km west of Alice Springs, dating from the Middle-Late Devonian roughly 380 million years old.
“It is difficult to pinpoint where Harajicadectes sits in this group of fish as it appears to have convergently acquired a mosaic of specialised features characteristic of widely separate branches of the tetrapodomorph radiation.”
The publication is the culmination of 50 years of exploration and research.
ANU Professor Gavin Young first discovered fragmentary specimens in 1973 and many more fossils recovered in 1991 have been studied by the Melbourne Museum and Geosciences Australia in Canberra.
Attempts to study these fossils proved troublesome until the Flinders University’s 2016 expedition found an almost complete specimen.
“This fossil demonstrated that all the isolated bits and pieces collected over the years belonged to a single new type of ancient fish,” says Dr Choo, from the College of Science and Engineering at Flinders.
The 2016 specimen has been transferred to the Museum and Art Galleries of the Northern Territory in Darwin.
Coauthors and collaborators on the paper include Professor Gavin Young (ANU and Australian Museum), Flinders fossil fish expert Dr Alice Clement, Dr Tom Challands from the University of Edinburgh, Dr Timothy Holland from the Geological Society of Australia and Dr Benedict King from the Max Planck Institute for Evolutionary Anthropology in Germany.
The article, A new stem-tetrapod fish from the Middle-Late Devonian of central Australia (2024) by B Choo, T Holland, AM Clement, B King, T Challands, JA Long and G Young has been published in the Journal of Vertebrate Palaeontology DOI: 10.1080/02724634.2023.2285000
Acknowledgements: This work was supported by the Australian Research Council via DECRA project DE1610024, and Discovery Grants DP0558499, DP0772138, DP160102460, and DP22100825.