The mysterious origins of Australia's bizarre and secretive marsupial moles have been cast in a whole new and unexpected light with the first discovery in the fossil record of one of their ancestors.
The find reveals a remarkable journey through time, place and lifestyle: living marsupial moles are blind, earless and live underground in the deserts of the Northern Territory, Western Australia and South Australia, yet their ancestors lived in lush rainforest far away in north Queensland.
In the journal Proceedings of the Royal Society B, a team led by Professor Mike Archer, of the University of New South Wales (UNSW), reports the discovery of the remarkable 20 million-year-old fossil at the Riversleigh World Heritage fossil site.
Although related to kangaroos, koalas and other marsupials, living marsupial moles far more closely resemble Cape golden moles, which burrow through the desert sands of Africa. The two golden-furred animals not only look indistinguishable when seen side by side but share many other similarities in their teeth and skeletons that reflect their subterranean lifestyles.
Yet the Cape golden mole is a placental mammal - the group that includes rats, bats, elephants and humans – and these two very different branches of the mammal family evolved from a common ancestor at least 125 million years ago, says Professor Archer. Having diverged in ancestry, however, their similar lifestyles have meant that they have converged in anatomy.
"This fossil discovery came as a real shock," he says. "Until now, we had always assumed that marsupial moles must have evolved in an unknown ancient Australian desert because, like Cape golden moles, the living marsupial moles survive only in deserts.
"Yet this ancestral Australian mole, which is not as specialised as the living form, has been discovered in ancient rainforest deposits—not deserts. The fossils suggest that they became mole-like while burrowing through the mossy floors of those ancient forests."
This missing link has solved a second mystery about how the highly specialised V-shaped teeth of the living marsupial mole evolved. Although they are almost identical to the teeth of their African counterparts, it is now clear that they went down a completely different evolutionary pathway to get there, says co-author Dr Robin Beck of the American Museum of Natural History.
"This ancient link makes it clear that marsupials followed a completely different path from placentals but ended up with almost identical-looking teeth."
Co-author UNSW Associate Professor Suzanne Hand said: "It goes to the heart of global debates about relationship versus convergence - whether animals are similar because they are closely related or similar because they have had to adapt to related challenges. It's also exciting because it so beautifully demonstrates just how adaptive Australian marsupials can be when given the right evolutionary challenges and enough time to meet them."
Riversleigh research is supported by the Xstrata Community Partnership Program North Queensland and the Australian Research Council. The fossil has been named Naraboryctes philcreaseri , with the species name honouring Phil Creaser, a strong supporter of the CREATE Foundation. http://www.create.unsw.edu.au
Diving robots find Antarctic seas exhale surprising amounts of carbon dioxide in winter
16.08.2018 | National Science Foundation
Diving robots find Antarctic winter seas exhale surprising amounts of carbon dioxide
15.08.2018 | University of Washington
Scientists at the University of California, Los Angeles present new research on a curious cosmic phenomenon known as "whistlers" -- very low frequency packets...
Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.
When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...
Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.
Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....
Proteins must be folded correctly to fulfill their molecular functions in cells. Molecular assistants called chaperones help proteins exploit their inbuilt folding potential and reach the correct three-dimensional structure. Researchers at the Max Planck Institute of Biochemistry (MPIB) have demonstrated that actin, the most abundant protein in higher developed cells, does not have the inbuilt potential to fold and instead requires special assistance to fold into its active state. The chaperone TRiC uses a previously undescribed mechanism to perform actin folding. The study was recently published in the journal Cell.
Actin is the most abundant protein in highly developed cells and has diverse functions in processes like cell stabilization, cell division and muscle...
Scientists have discovered that the electrical resistance of a copper-oxide compound depends on the magnetic field in a very unusual way -- a finding that could help direct the search for materials that can perfectly conduct electricity at room temperatur
What happens when really powerful magnets--capable of producing magnetic fields nearly two million times stronger than Earth's--are applied to materials that...
08.08.2018 | Event News
27.07.2018 | Event News
25.07.2018 | Event News
16.08.2018 | Life Sciences
16.08.2018 | Earth Sciences
16.08.2018 | Life Sciences