Extinct fanged kangaroos, new research


This video says about itself:

The Fossil Record and Evolution of Kangaroos

28 February 2016

I would first like to give visual credit to BBC Earth, which they have some epic shots on kangaroos.

From the University of Queensland in Australia:

Fanged kangaroo research could shed light on extinction

October 16, 2017

Fanged kangaroos — an extinct family of small fanged Australian kangaroos — might have survived at least five million years longer than previously thought.

A University of Queensland-led study has found the species might have competed for resources with ancestors of modern kangaroos.

Research into species diversity, body size and the timing of extinction found that fanged kangaroos, previously thought to have become extinct about 15 million years ago, persisted to at least 10 million years ago.

The fanged kangaroos, including the species Balbaroo fangaroo, were about the size of a small wallaby.

UQ School of Earth and Environmental Sciences PhD student Kaylene Butler said the research involved Queensland Museum holdings of ancient fossil deposits from the Riversleigh World Heritage Area, where kangaroo fossil evidence goes back as far as 25 million years.

“Fanged kangaroos and the potential ancestors of modern kangaroos are both browsers — meaning they ate leaves — and they scurried, but did not hop,” Ms Butler said.

“Northern Queensland was predominantly covered in rainforest when these fanged kangaroos first appear in the fossil record.

“There is a lot of research to be done before we can be sure what their canine teeth were used for but some have suggested they were used to attract potential mates. We do know that despite their large canines they were herbivorous (plant eaters).

“We found that fanged kangaroos increased in body size right up until their extinction.”

Ms Butler said the research aimed to fill significant gaps in the understanding of kangaroo evolution, and new fossil finds were helping to bring ancient lineages into focus.

“Currently 21 macropod species are listed as vulnerable or endangered on the International Union for the Conservation of Nature Red List of Threatened Species,” she said.

She said understanding when and why kangaroos went extinct in the past could help with understanding what drove extinction of such animals.

“Currently, we can only hypothesise as to why balbarids became extinct — the original hypothesis related to events during a change in climate 15 million years ago but the balbarids persisted past that,” she said.

“This new finding of their persistence until 10 million years ago means something else must have been at play, such as being outcompeted by other species.”

Ms Butler last year discovered two new ancient species of kangaroo, Cookeroo bulwidarri and Cookeroo hortusensis.

She has worked on fossil material as part of her PhD research supervised by former UQ Robert Day Fellow Dr Kenny Travouillon, now of the Western Australian Museum, and UQ’s Dr Gilbert Price.

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Tasmanian devil-like fossil marsupial discovery in Turkey


An artist’s reconstruction of Anatoliadelphys maasae. Image credit: Peter Schouten

From the University of Salford in England:

‘Euro Devil’: Fossil of carnivorous marsupial relative discovered in E Europe

August 17, 2017

Scientists have discovered fossil remains of a new carnivorous mammal in Turkey, one of the biggest marsupial relatives ever discovered in the northern hemisphere.

The findings, by Dr Robin Beck from the University of Salford in the UK and Dr Murat Maga, of the University of Washington who discovered the fossil, are published today in the journal PLoS ONE.

The new fossil is a 43 million year old cat-sized mammal that had powerful teeth and jaws for crushing hard food, like the modern Tasmanian Devil. It is related to the pouched mammals, or marsupials, of Australia and South America, and it shows that marsupial relatives, or metatherians, were far more diverse in the northern hemisphere than previously believed.

Dr Maga found the fossil at a site near the town of Kazan, northwest of the Turkish capital, Ankara. It has been named Anatoliadelphys maasae, after the ancient name for Turkey, and Dr Mary Maas, a Turkish-American palaeontologist. The fossil is remarkably well preserved, and includes parts of the skull and most of the skeleton.

It shows that Anatoliadelphys weighed 3-4 kilograms, about the size of a domestic cat, and that it was capable of climbing. It had powerful teeth and jaws, for eating animals and possibly crushing bones. Features of the teeth and bones of Anatoliadelphys show that is closely related to marsupials, but it is not known whether it had a pouch or not.

Dr Beck, who is a world expert in the evolution of marsupials and their fossil relatives, said: “This was definitely an odd little beast — imagine something a bit like a mini-Tasmanian devil that could climb trees.

“It could probably have eaten pretty much anything it could catch — beetles, snails, frogs, lizards, small mammals, bones, and probably some plant material as well. This find changes what we thought we knew about the evolution of marsupial relatives in the northern hemisphere — they were clearly a far more diverse bunch than we ever suspected.”

Most fossil metatherians from the northern hemisphere were insect-eating creatures no bigger than mice or rats, whereas Anatoliadelphys was ten times larger and could have eaten vertebrate prey.

“It might seem odd to find a fossil of a marsupial relative in Turkey, but the ancestors of marsupials actually originated in the northern hemisphere, and they survived there until about 12 million years ago,” said Dr Beck.

The region of Turkey where Anatoliadelphys was found was probably an island 43 million years ago, which may have enabled Anatoliadelphys to survive without competition from carnivorous placental mammals, such as fossil relatives of cats, dogs and weasels.

Today, many marsupials in Australia have been driven to extinction due to the introduction of the dingo, cats and foxes, suggesting that marsupials may be competitively inferior to placentals.

See also here.

How kangaroos stay cool


This video says about itself:

Amazing Kangaroo Technique To Stay Cool – Planet Earth – BBC Earth

2 April 2017

Australia is the world’s most arid continent, and its blistering daytime heat can be a potential killer. Using thermal imaging, we are given a fascinating glimpse into how the Red Kangaroos cool their body temperatures and avoid the deadly effects of the mid day sun.

Fossil marsupials discovery in Bolivia


This video says about itself:

24 April 2015

The Evolution Of Mammals

Description: The word “mammal” is modern, from the scientific name Mammalia coined by Carl Linnaeus in 1758, derived from the Latin mamma (“teat, pap”). All female mammals nurse their young with milk, which is secreted from special glands, the mammary glands.

According to Mammal Species of the World, 5,416 species were known in 2006. These were grouped in 1,229 genera, 153 families and 29 orders.[1] In 2008 the IUCN completed a five-year, 1,700-scientist Global Mammal Assessment for its IUCN Red List, which counted 5,488 accepted species at the end of that period.[2] In some classifications, the mammals are divided into two subclasses (not counting fossils): the Prototheria (order of Monotremata) and the Theria, the latter composed of the infraclasses Metatheria and Eutheria. The marsupials constitute the crown group of the Metatheria and therefore include all living metatherians as well as many extinct ones; the placentals likewise constitute the crown group of the Eutheria.

From Case Western Reserve University in the USA:

Three new species of extinct South American marsupials discovered

Findings show the family, Palaeothentidae, was once widespread across the continent but add to extinction doubts

April 11, 2017

The discovery of three extinct species and new insights to a fourth indicates a little-known family of marsupials, the Palaeothentidae, was diverse and existed over a wide range of South America as recent as 13 million years ago. Fossils of the new species were found at Quebrada Honda, a high elevation fossil site in southern Bolivia, and are among the youngest known palaeothentid fossils.

The discovery of three extinct species and new insights to a fourth indicates a little-known family of marsupials, the Palaeothentidae, was diverse and existed over a wide range of South America as recent as 13 million years ago.

The finding, however, complicates the question: why did these animals go extinct?

“It was previously assumed this group slowly went extinct over a long time period, but that’s probably not the case,” said Russell Engelman, a biology MS student at Case Western Reserve and lead author of a new study on the group. “They were doing very well at the time they were supposedly on death’s door.”

Discovering new fossil sites may be the only way to learn the answer, researchers say.

Engelman; along with Federico Anaya, professor of geological engineering at Universidad Autónoma Tomás Frías, in Potosí, Bolivia; and Darin Croft, anatomy professor at Case Western Reserve School of Medicine, describe the animals, where they fit in the family, and their paleoecology and paleobiology in the Journal of Systematic Palaeontology.

Fossils of the new species were found at Quebrada Honda, a high elevation fossil site in southern Bolivia. They are about 13 million years old (from the middle Miocene epoch), placing them among the youngest known palaeothentid fossils.

Fossil remains of other members of the family, and other relatives within the order Paucituberculata, have been found at sites of similar age in southwestern Colombia and possibly southern Argentina, geographically spanning almost the entire continent.

“The only close relatives of palaeothentids alive today are shrew opossums, small, poorly-known, ground-living marsupials that live in and near the Andes,” Croft said. “Palaeothentid marsupials once included a diversity of species that filled a variety of roles in ancient ecosystems. During their heyday in the Miocene, they were abundant.”

The new species, Palaeothentes serratus, Palaeothentes relictus, and Chimeralestes ambiguus, all had long snouts but differed in diet and body size and other features.

The researchers suggest P. serratus — serratus means saw-like — was an insectivore, with well-developed slicing premolars. The researchers estimate the mouse-size marsupial weighed about 3.5 ounces.

P. relictus had large, well-developed grinding molars. The animal probably ate fruits, seeds and insects, and weighed about five ounces.

C. ambiguus, as the name indicates, has attributes of a number of family members, making its evolutionary relationships with the group uncertain. The animal was about the same size as P. serratus and its limited dental remains indicate its diet was likely similar to that of P. relictus.

The most common member of the family found at Quebrada Honda is Acdestis maddeni. The species was named 14 years ago, but the researchers are the first to find and analyze its lower jaw.

These lower jaw fossils, combined with reexamination of other specimens, show that the skull of Acdestis was different from other palaeothentids. A. maddeni’s snout is short and its canines are relatively large, followed by large, shearing middle teeth and molars well developed for grinding.

“All this indicates it was a generalist,” Engelman said. “Although it could eat fruits and insects like its relatives it could also catch small vertebrates and dismember them… It probably ate anything, like a hedgehog or Norway rat does.”

The animal was rat-size and weighed about a pound, the researchers estimate.

The fossil record indicates the Palaeothentidae and much of the order Paucituberculata abruptly went extinct about 12 million years ago, leaving only the lineage leading to modern shrew-opossums.

“Most species threatened with extinction are like giant pandas: highly specialized, live only in a certain area and eat only certain things,” Engelman said. Due to their diversity and wide range, “the Palaeothentidae didn’t fit the pattern of extinction.”

Previous hypotheses that palaeothentids were done in by climate change or competition lack support, the researchers say.

For example, fossils found at high latitudes in Argentina and Bolivia after the Middle Miocene Climatic Optimum indicate they withstood the dramatic cooling of the period. The family and opossums, which may have been competitors, appear to have overlapped for nearly 10 million years. Yet opossums didn’t become abundant until 3 million to 4 million years after the family went extinct.

But, the hypothesis cannot be completely ruled out, the researchers said. And, there is a possibility the decline of the family was slow.

The reason for the quandary is that fossils have been well collected in the southern end of South America but the middle and northern parts of the continent remain largely unexplored.

“It’s as if all the fossils in the U.S. came from Florida — you don’t get the full picture,” Engelman said.

If new fossil sites are found in the northern two-thirds of the continent, “it will be interesting to see whether we find younger members of the group,” Croft said. “That will help us understand their extinction.”

Wallaby joey’s first time outside the pouch, video


This 4 April 2017 is about a young (joey) Bennett’s wallaby. After being inside its mother’s pouch for six months, this is the first time that this baby marsupial comes to the outside world.

This recording of these originally Australian animals is from Artis zoo in Amsterdam in the Netherlands.

New marsupial species discovery in Brazil


THis video from the USA says about itself:

8 May 2012

My daughter’s grandfather captured this video of a mother [Virginia] opossum transporting 15 baby opossums on her back. Amazing!

From National Geographic:

New Redheaded Opossum Named After Magical Gnome

The rat-size marsupial prowls the tropical rain forests of northern Brazil at night.

By Carrie Arnold

PUBLISHED February 23, 2017

A chance finding at a Brazilian museum has revealed a brand-new species of opossum.

Biologist Silvia Pavan first discovered an unnamed mammal specimen with rich mahogany fur in 2008 at the Museu Paraense Emílio Goeldi in Belém.

The rat-size marsupial’s reddish head inspired its name: Monodelphis saci.

Brazilian folklore features a gnome called the saci (pronounced sah-SEE), who wears a magical red cap that lets him disappear and reappear at will. (See “Unbelievably Cute Mammal With Teddy Bear Face Rediscovered.”)

Just like the saci, the new species of opossum has a red cap—and had been hiding in plain sight.

“I analyzed the specimen right away when it was brought to the museum, and I noticed it didn’t have a name,” says Pavan, lead author of the new study in the journal American Museum Novitates.

After that, she was able to find other specimens representing the same unnamed species in Brazilian collections.

Playing Possum

Opossums evolved in the South American tropics; several dozen species live in the Americas, but only the Virginia opossum made it as far north as the United States.

All opossum species are nocturnal omnivores, eating a range of fruit, insects, and small mammals—a flexibility that has allowed them to spread far and wide. (Read how opossum blood may help snakebite victims.)

As part of her Ph.D. work at the American Museum of Natural History, Pavan wanted to piece together the opossum family tree. But with so many species sprinkled across so many habitats, Pavan went to museums to supplement her search for opossums in the wild.

After she came across the gnome opossum, her colleagues traveled to the source—Itaituba I National Forest in Pará, Brazil—to see if they could find live animals.

Mysterious Marsupials

Pavan’s colleagues set up a series of humane pitfall traps—basically small buckets that capture opossums as they prowl the tropical rain forest at night.

To her surprise, Pavan discovered several more gnome opossums in her buckets. (Also see “Newly Discovered Carnivore Looks Like Teddy Bear.”)

“They’re not really that rare, but they only appeared in scientific collections relatively recently when people started using the pitfall traps,” she says.

The species doesn’t appear to be threatened with extinction, though more people have been collecting the animal in the wild in the weeks since her discovery was announced, she says.

Guillermo D’Elia, a biologist at the Austral University of Chile in Valdivia, says there are likely more marsupials to be identified.

“I am pretty sure there are several new species of opossum to come in the future,” D’Elia says, “now that researchers are collecting in new areas, rechecking museum specimens, and using DNA.”