Researchers have discovered a 380-million-year-old fossilised heart, along with other internal organs of prehistoric fish. This exciting discovery is not only helping palaeontologists to understand the internal organs of placoderms, these fossils are also providing a fresh perspective on our own evolution.

Fossilised Internal Organs in Ancient Armoured, Jawed Fish

The remarkably well-preserved fossils representing the Devonian placoderm Compagopiscis, come from the famous Gogo Formation, in the Kimberley region of Western Australia. The Gogo Lagerstätte preserves the fauna that once thrived on an ancient, shallow water reef. The fossils are thought to be around 380 million years old (Frasnian faunal stage of the Late Devonian).

Soft Tissues Including Liver and Intestines but No Evidence of Lungs

The international research team led by scientists from Curtin University and the Western Australia Museum have published their findings in the academic journal “Science”. They have identified a number of internal organs preserved in three-dimensions including the liver and intestines. Additionally, the fossils show that the lungs are absent, refuting the hypothesis that lungs are ancestral in jawed vertebrates.

Details Revealed by Computerised Tomography

In collaboration with scientists at the Australian Nuclear Science and Technology Organisation in Sydney and the European Synchrotron Radiation Facility in Grenoble, France, researchers used neutron beams and synchrotron x-rays to scan the specimens, still embedded in limestone concretions. They constructed three-dimensional, computer-generated images of the soft tissues inside them based on the different densities of minerals deposited by the bacteria and the surrounding rock matrix.

Lead researcher and John Curtin Distinguished Professor Kate Trinajstic (Curtin’s School of Molecular
and Life Sciences and the Western Australian Museum), commented that to find three-dimensionally preserved tissues in Devonian fossils was an extremely rare event.

Professor Trinajstic explained:

“As a palaeontologist who has studied fossils for more than 20 years, I was truly amazed to find a 3-D and
beautifully preserved heart in a 380-million-year-old ancestor. Evolution is often thought of as a series of small steps, but these ancient fossils suggest there was a larger leap between jawless and jawed vertebrates. These fish literally have their hearts in their mouths and under their gills – just like sharks today.”

The Complex Heart of an Arthrodiran

This is the first time a 3-D representation of the heart of a member of the Arthrodira has been found. The Arthrodira are an extinct Order of jawed, armoured fish within the Class Placodermi. They thrived in the Devonian and some arthrodirans evolved into apex predators such as the huge Dunkleosteus.

The surprising complex heart is s-shaped and consists of two chambers with the smaller chamber sitting on top. Professor Trinajstic stated that these features were advanced in such early vertebrates, offering scientists a unique perspective on how the head and neck region began to change to accommodate jaws, a critical stage in the evolution of animals with backbones.

Learning About the Anatomy of a Primitive Jawed Fish

The discovery and subsequent detailed analysis of these mineralised soft tissues, in combination with earlier studies looking at muscle structure, placoderm embryos and evidence of viviparity makes the Gogo Lagerstätte an exceptionally important fossil resource as researchers strive to improve their knowledge of early vertebrates.

Professor Trinajstic added:

“For the first time, we can see all the organs together in a primitive jawed fish, and we were especially surprised to learn that they were not so different from us. However, there was one critical difference – the liver was large and enabled the fish to remain buoyant, just like sharks today. Some of today’s bony fish such as lungfish and bichirs have lungs that evolved from swim bladders, but it was significant that we found no evidence of lungs in any of the extinct armoured fishes we examined, which suggests that they evolved independently in the bony fishes at a later date.”

The Stuff of Palaeontologists’ Dreams

Co-author of the scientific paper, Professor John Long (Flinders University, Adelaide, South Australia) commented:

“These new discoveries of soft organs in these ancient fishes are truly the stuff of palaeontologists’ dreams, for without doubt these fossils are the best preserved in the world for this age. They show the value of the Gogo fossils for understanding the big steps in our distant evolution. Gogo has given us world firsts, from the origins of sex to the oldest vertebrate heart, and is now one of the most significant fossil sites in the world. It’s time the site was seriously considered for world heritage status.”

To read an earlier blog post about a fossil from the Upper Devonian Gogo Formation that indicates live birth (viviparity) in placoderms: Evidence of Live Birth (Viviparity) in a 380-million-year-old Fish.

Exceptional Fossils Meet Exceptional Technology

Co-author of the paper Professor Per Ahlberg (Uppsala University, Sweden) explained that access to state-of-the-art, non-destructive scanning technology enabled scientists to make such exceptional discoveries.

Professor Ahlberg explained:

“What’s really exceptional about the Gogo fishes is that their soft tissues are preserved in three dimensions. Most cases of soft-tissue preservation are found in flattened fossils, where the soft anatomy is little more than a stain on the rock. We are also very fortunate in that modern scanning techniques allow us to study these fragile soft tissues without destroying them. A couple of decades ago, the project would have been impossible.”

A Collaborative Effort

The research was truly a collaborative effort not only involving the Australian Nuclear Science and Technology Organisation and the European Synchrotron Radiation Facility, but also scientists from Flinders University, the Western Australian Museum, Uppsala University, South Australia Museum and Monash University’s Australian Regenerative Medicine Institute.

Everything Dinosaur acknowledges the assistance of a media release from Curtin University in the compilation of this article.

The scientific paper: “Exceptional preservation of organs in Devonian placoderms from the Gogo lagerstätte” by Kate Trinajstic, John A. Long, Sophie Sanchez, Catherine A. Boisvert, Daniel Snitting, Paul Tafforeau, Vincent Dupret, Alice M. Clement, Peter D. Currie, Brett Roelofs, Joseph J. Bevitt, Michael S. Y. Lee and Per E. Ahlberg published in the journal Science.

A new species of dinosaur has been described from fossils found in Neuquén Province (Argentina). Named Elemgasem nubilus it is the first unambiguous abelisaurid known from the Coniacian faunal stage of the Late Cretaceous.

A field team of CONICET researchers have excavated the fragmentary remains of a new species of carnivorous dinosaur from Upper Cretaceous exposures near to the city of Plaza Huincul, in the province of Neuquén in Patagonia (Argentina). The fossils come from the Portezuelo Formation and represent an individual animal around four metres in length and standing approximately two metres tall. Bone histology revealed that this abelisaurid was around eight years old when it died. The histological analysis suggests that Elemgasem probably would not have grown much bigger, making this predator much smaller than related abelisaurids such as Carnotaurus and Ekrixinatosaurus.

Regarded as a sub-adult, the scientists who include co-author Rodolfo Coria (Universidad Nacional de Río Negro, Argentina), writing in the journal of The Palaeontological Association conclude that this dinosaur had already reached sexual maturity.

Documenting the Evolution of the Abelisauridae

The Abelisauridae are a diverse group of medium-to-large-sized predatory dinosaurs predominately associated with the landmass of Gondwana. Numerous genera have been described based on fossils found in the Southern Hemisphere and they are known from almost all parts of Gondwana in all the faunal stages associated with the Late Cretaceous, except for the Coniacian (90 to 86 mya approximately).

This period in Earth’s history is marked by a turnover in terrestrial and marine fauna due to global climate change leading to worldwide extinctions.

Explaining the significance of these fossils, co-author Rodolfo Coria stated:

“The identification of a new species is always a scientifically relevant event, especially if the species belongs to an emblematic family of carnivorous dinosaurs such as the abelisaurs. Elemgasem represents a key piece in the puzzle of the evolution of this group, which began to be put together with the first findings of José Bonaparte, the most important Argentinean vertebrate palaeontologist of the 20th century – in the 1980s”

Although the fossil material is fragmentary, a new genus has been erected based on several autapomorphies including notable rugosity on the lateral surface of the fibula and the shape of the tail bones which are different from any other abelisaurid described to date.

The First Abelisaurid from the Portezuelo Formation (New Abelisaurid)

Elemgasem is the first abelisaurid described from fossils from the Portezuelo Formation and it was part of a diverse dinosaur-dominated terrestrial fauna with several different types of theropod present including dromaeosaurids, alvarezsaurids and megaraptorids.

Phylogenetic analysis indicates the E. nubilus could be tentatively assigned to the Brachyrostra tribe within the Carnotaurinae subfamily, although the limited amount of fossilised material prevented the researchers from making a more positive taxonomic assessment.

The genus name is derived from the name of a god in the regional Tehuelche culture and the trivial name is from the Latin for “cloudy days”, a reference to the strange, foggy conditions that the dig team encountered whilst they worked in the field.

Dr Coria added:

“We already knew of abelisaurian forms in older horizons [such as the Cenomanian] or more modern ones [such as the Campanian], so it was predictable that there would be some in intermediate times. What we did not expect was to find a comparatively small abelisaur like Elemgasem, whose size is clearly smaller than the rest of the species in the group, such as Carnotaurus, Aucasaurus or Skorpiovenator.”

It is the first abelisaurid from the Turonian–Coniacian interval and it increases the diversity of this theropod family at a time of marked turnover in the tetrapod fauna of South America.

Rebor has introduced several scale replicas of abelisaurid dinosaurs. To view the extensive range of Rebor models and figures available from Everything Dinosaur: Rebor Figures and Models.

Everything Dinosaur acknowledges the assistance of a media release from CONICET in the compilation of this article.

The scientific paper: “Elemgasem nubilus: a new brachyrostran abelisaurid (Theropoda, Ceratosauria) from the Portezuelo Formation (Upper Cretaceous) of Patagonia, Argentina” by Mattia A. Baiano, Diego Pol, Flavio Bellardini, Guillermo J. Windholz, Ignacio A. Cerda, Alberto C. Garrido and Rodolfo A. Coria published in Papers in Palaeontology.

Back in June (2022), Everything Dinosaur team members wrote about the “White Rock spinosaurid” *, what could turn out to be the biggest predatory dinosaur found to date in Europe. At the time, many media outlets mistakenly reported that these fossils, found on the Isle of Wight, represented “Europe’s biggest dinosaur”. Not true, the remains of what could be the largest dinosaur ever discovered in Europe are being excavated in a Portuguese back garden.

Giant Sauropod

The first fossils were uncovered in 2017 when the property owner in the city of Pombal, in the Leiria District, central Portugal, began construction work in the garden. The strata in this area of Portugal were laid down approximately 150 million years ago (Upper Jurassic) and the fossils are from a sauropod, a long-necked, long-tailed herbivore that could have measured more than 25 metres long.

A joint Spanish/Portuguese field team have been working to expose, stabilise and remove the fossilised bones. In the picture above, two ribs have been coated in plaster and burlap in preparation for their removal from the site.

A European Brachiosaurid

Tentatively described as a member of the Brachiosauridae family, parts of the backbone and ribs have been excavated so far. The bones were found in virtually their original articulated and anatomical position.

Elisabete Malafaia, post-doctoral researcher at the Faculty of Sciences of the University of Lisbon and member of the field team excavating the giant bones stated that it was extremely unusual to find all the ribs of a sauropod, almost entirely intact. The skeleton was found in the position that the dinosaur probably died in, no post-mortem transport of the corpse took place.

The field team are optimistic that more bones remain buried, including the skull. To find an almost complete skeleton of this type of dinosaur would be a truly remarkable discovery with the potential to provide scientists with an enormous amount of data on Late Jurassic sauropods.

A Member of the Macronaria

The Neosauropoda clade, a sub-group within the Sauropoda is divided into two sub-clades. The Diplodocoidea and the Macronaria. The Macronaria are distinguished by having a large nasal (external naris), the diameter of the nasal opening exceeding the diameter of the eye socket (orbit). Brachiosaurids and the titanosaurs, which thrived during the Cretaceous, represent some of the biggest land animals to have ever existed.

It has been speculated that the head height of the Portuguese sauropod could be as much as 12 metres, that would make this dinosaur tall enough to look over a three-storey house!

Years of Laboratory Work Ahead

Dinosaur fans will have to be patient and wait for a formal scientific description. It is likely to take several years to fully prepare and study the huge, fossilised bones, of what is probably a new dinosaur species. A spokesperson from Everything Dinosaur commented that this was an amazing fossil find and that this Portuguese discovery could rival some of the sauropod fossils found in the roughly contemporaneous Morrison Formation of the western United States.

Everything Dinosaur contacted the Faculty of Sciences of the University of Lisbon media team to request images for this blog post, we acknowledge their assistance in the compilation of this article. The University’s press team kindly responded, supplied images and wrote:

“Obrigada pelo interesse neste trabalho. Partilho aqui algumas imagens com boa resolução.”

This translates as “thank you for your interest in this work, here are some high-resolution images for you.”

We look forward to hearing more about this remarkable discovery and the eventual naming and scientific description of a huge sauropod from a Portuguese garden.

“White Rock spinosaurid” * – to read Everything Dinosaur’s article from June, 2022 on the discovery of potentially Europe’s largest carnivorous dinosaur known to date: Super-sized Carnivorous Dinosaur from the Isle of Wight.