Fossilised 'Giant' discovered on Kangaroo Island
Fossils of a giant new species from the long-extinct group of sea creatures called trilobites have been found on Kangaroo Island, South Ӱֱ.
The finding is adding important insights to our knowledge of the Cambrian ‘explosion’, the greatest diversification event in the history of life on Earth, when almost all animal groups suddenly appeared over half-a-billion years ago.
Trilobites, which had hard, calcified, armour-like skeletons over their bodies, are related to modern crustaceans and insects. They are one of the most successful fossil animal groups, surviving for about 270 million years (521 to 252 million years ago). Because of their abundance in the fossil record, they are considered a model group for understanding this evolutionary period.
“We decided to name this new species of trilobiteRedlichia rex(similar toTyrannosaurus rex) because of its giant size, as well as its formidable legs with spines used for crushing and shredding food – which may have been other trilobites,” saysJames Holmes, PhD student with the Ӱֱ of Adelaide’s School of Biological Sciences, who led the research.
The preservation of trilobite ‘soft parts’ such as the antennae and legs is extremely rare. The new species was discovered at the Emu Bay Shale on Kangaroo Island, a world-renowned deposit famous for this type of preservation. The findings have been published in theby a team of scientists from the Ӱֱ of Adelaide, South Ӱֱn Museum and the Ӱֱ of New England.
The new species is about 500 million years old, and is the largest Cambrian trilobite discovered in Ӱֱ. It grew to around 30 cm in length, which is almost twice the size of other Ӱֱn trilobites of similar age.
“Interestingly, trilobite specimens from the Emu Bay Shale – includingRedlichia rex– exhibit injuries that were caused by shell-crushing predators,” says senior study author, from the Ӱֱ of Adelaide and the South Ӱֱn Museum.
“There are also large specimens of fossilised poo (or coprolites) containing trilobite fragments in this fossil deposit. The large size of injuredRedlichia rexspecimens and the associated coprolites suggests that either much bigger predators were targetingRedlichia rex, such asAnomalocaris– an even larger shrimp-like creature – or that the new species had cannibalistic tendencies.”
One of the major drivers of the Cambrian explosion was likely an evolutionary “arms race” between predators and prey, with each developing more effective measures of defence (such as the evolution of shells) and attack.
“The overall size and crushing legs ofRedlichia rexare a likely consequence of the arms race that occurred at this time” says James Holmes. “This giant trilobite was likely the terror of smaller creatures on the Cambrian seafloor.”
Specimens ofRedlichia rexand other Emu Bay Shale fossils are currently on display in the South Ӱֱn Museum.
Article from the News Archives.
The finding is adding important insights to our knowledge of the Cambrian ‘explosion’, the greatest diversification event in the history of life on Earth, when almost all animal groups suddenly appeared over half-a-billion years ago.
Trilobites, which had hard, calcified, armour-like skeletons over their bodies, are related to modern crustaceans and insects. They are one of the most successful fossil animal groups, surviving for about 270 million years (521 to 252 million years ago). Because of their abundance in the fossil record, they are considered a model group for understanding this evolutionary period.
“We decided to name this new species of trilobiteRedlichia rex(similar toTyrannosaurus rex) because of its giant size, as well as its formidable legs with spines used for crushing and shredding food – which may have been other trilobites,” saysJames Holmes, PhD student with the Ӱֱ of Adelaide’s School of Biological Sciences, who led the research.
The preservation of trilobite ‘soft parts’ such as the antennae and legs is extremely rare. The new species was discovered at the Emu Bay Shale on Kangaroo Island, a world-renowned deposit famous for this type of preservation. The findings have been published in theby a team of scientists from the Ӱֱ of Adelaide, South Ӱֱn Museum and the Ӱֱ of New England.
The new species is about 500 million years old, and is the largest Cambrian trilobite discovered in Ӱֱ. It grew to around 30 cm in length, which is almost twice the size of other Ӱֱn trilobites of similar age.
“Interestingly, trilobite specimens from the Emu Bay Shale – includingRedlichia rex– exhibit injuries that were caused by shell-crushing predators,” says senior study author, from the Ӱֱ of Adelaide and the South Ӱֱn Museum.
“There are also large specimens of fossilised poo (or coprolites) containing trilobite fragments in this fossil deposit. The large size of injuredRedlichia rexspecimens and the associated coprolites suggests that either much bigger predators were targetingRedlichia rex, such asAnomalocaris– an even larger shrimp-like creature – or that the new species had cannibalistic tendencies.”
One of the major drivers of the Cambrian explosion was likely an evolutionary “arms race” between predators and prey, with each developing more effective measures of defence (such as the evolution of shells) and attack.
“The overall size and crushing legs ofRedlichia rexare a likely consequence of the arms race that occurred at this time” says James Holmes. “This giant trilobite was likely the terror of smaller creatures on the Cambrian seafloor.”
Specimens ofRedlichia rexand other Emu Bay Shale fossils are currently on display in the South Ӱֱn Museum.
Article from the News Archives.
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