Dr Espen Knutsen is a Senior Curator Palaeontology at the Queensland Museum Network. As a key collaborator on the new exhibition, Sea Monsters: Prehistoric Ocean Predators, we chatted to Espen to uncover more about his fascinating career and discoveries.

What is your favourite species in the collection and why?

I have many favourite specimens in the Queensland Museum collections, one of which is the skull of Eromangasaurus, a long-necked plesiosaur (marine reptile) from the Early Cretaceous inland sea of Australia. This is a very unique specimen, as it is the only head we have of any such animal in Australia. Having a very long neck (often 2/3^rds of the total bodylength) is a likely reason why the heads of these animals are rarely found as fossils, as the “thin” neck would be one of the first parts of the animal to break apart during decomposition. Unfortunately, we don’t know what the body that goes with the body looks like, as only the head of this individual was discovered. What we need now is a head and body together to figure out if any of the plesiosaur bodies we have at QM goes with the head of Eromangasaurus.

Do you have any interesting facts?

Queensland preserve a vast array of fossils spanning the last 1.65 billion years. This includes the animals and plants that lived directly before and after the most extensive mass extinction in Earth’s history, at the end of the Permian period, 252 mya. Fossil of tiny (<10cm long) to medium sized reptiles and amphibians found in central Queensland show how ecosystems recovered following this disaster. Representing one of only a few such sites in the southern hemisphere, these fossils are of global importance.

The Early Cretaceous (~100mya) inland sea in Queensland was home to one of the largest predatory marine reptiles to ever exist, Kronosaurus. At around 10-12m long, with a 2m head sporting cucumber sized teeth, this four-flippered reptile likely ate anything is came across in this ancient sea.

Platypterygius, another marine reptile from the Early Cretaceous of Queensland belonging to the group ichthyosaurs, was one of the last of its kind before the group went extinct around 95 million years ago.

A group of short-necked plesiosaurs called polycotylids adapted to fill in many of the niches occupied by ichthyosaurs before they went extinct around 95 mya. One of the world’s most primitive members of these short-necked and long-snouted plesiosaurs have been found in Queensland, and is also the most complete skeleton of any plesiosaur in Australia. This specimen is currently un-named and on loan to the Kronosaurus Korner museum in Richmond, northern Queensland.

I estimate that there are this many species waiting to be formally described…

Estimating the number of extinct species awaiting description is riddled with assumptions. Some estimates of the total number of vertebrate species currently present on Earth are around 66 000, and that the average longevity of a species is around 1 million years. Just over the time span covered by the Mesozoic Era (252-66 mya) this could mean as much as 12.3 million vertebrate species. It has been suggested that of all organisms that have ever existed only about 1% have actually been fossilised. If this is the case, there should be at least 123 000 Mesozoic vertebrate species out there. Approximately 7000 fossil Mesozoic species are known this far, leaving about 116 000 species to be discovered. However, not all fossils are available to be found. Some are still covered by hundreds of meters of rock and sediment.

Tell us a little bit about your area and why do you love working in this specific research area?

Palaeontology is the only window we have into ancient life on Earth, and thus to our own past. As such, it is not only a very interesting field to work in as you get to dig up large reptiles, such as dinosaurs and plesiosaurs, but these finds are also essential to learning from the past to better the future of our planet and all life on it, including us.

What is your favourite thing about your role at the museum? Why?

What I really enjoy about my job is that I get to work on projects that I find really interesting and rewarding. There is always something new to discover and new ways to interpret fossil and the rocks they are found in. I also get to be the first individual, human or other, to lay eyes on the remains of animals and plants that lived and died millions of years ago.

What is one of the most interesting facts you have discovered through working at the museum?

One of the more interesting facts I have discovered while working at the Queensland Museum is that a long-held belief that animals called dicynodonts (a group of stem-mammals that went extinct at the end of the Triassic period 202 mya) persisted in Queensland more than 100 million years after they went extinct everywhere else, was based on a misinterpretation of a fragmentary fossil discovered in northern Queensland a hundred years ago. By scouring old museum archives and using cutting-edge technologies such as CT scanning and fossil bone geochemistry, I learned that the fossil was actually that of a much more recent marsupial, not a dicynodont.

What is your favourite exhibition at the museum (current or past) and why?

My favourite exhibition at Museum of Tropical Queensland so far has been the Dinosaur revolution exhibit, because it featured a lot of dinosaurs of course!

What’s your favourite sea monster featured in Sea Monsters: Prehistoric Ocean Predators and why?

I think the plesiosaurs are amazing creatures. They don’t look like anything around today, and their way of swimming using four flippers is also unheard of in recent animals.

Sea Monsters: Prehistoric Ocean Predators is on at Queensland Museum until 3 May 2021. Visit today.