Giraffe ancestor discovery in Spain


This video says about itself:

1 November 2017

Ancient Fossil Offers a New European Ancestor to Giraffes

A near-perfect fossil unearthed close to Madrid appears to be an ancient European ancestor of giraffes, representing a new species in the family and one that had two sets of bony bumps on its head rather than the single set of modern giraffes.

Older fossils in the family known as giraffids have been found before, but none in such pristine condition, said Ari Grossman, an associate professor of anatomy at Midwestern University in Glendale, Ariz., who was not involved in the finding but said the whole field would benefit from it.

“It’s something most paleontologists dream of and very rarely find,” Dr. Grossman said. “The discovery in and of itself was breathtaking.”

Fossils of three other animals of the same species named Decennatherium rex by the researchers were also found, according to a new study in the journal PLOS One. They were not as complete, but all are about nine million years old and provide evidence that ancestors in the giraffe family lived deep inside Europe much earlier than had been suspected. The fossils also suggest that there were physical differences between males and females.

From PLOS ONE:

Newly described giraffid species may help trace evolution of giraffe ancestors

Unusually complete fossil extends range, timespan of sivathere-samothere giraffids

November 1, 2017

A new giraffid species from Spain may extend the range and timespan of the ancestors of giraffes, according to a study published November 1, 2017 in the open access journal PLOS ONE by María Ríos from the National Museum of Natural History, Spain, and colleagues.

The giraffids, a family of ruminants that includes modern day giraffes and okapis, are thought to have existed as far back as the early Miocene epoch. While fossils from over 30 extinct species have been described, the lack of fossilised skulls has been a barrier to determining evolutionary relationships.

The authors of the present study describe a new large giraffid species, named Decennatherium rex sp. nov., from the Spanish province of Madrid. The fossilized skeleton is thought to date from the late Miocene and is unusually complete, providing the researchers with new anatomical and phylogenetic data.

The authors conducted a phylogenetic analysis to help elucidate evolutionary patterns. The results suggest that the Decennatherium genus may have been the most basal branch of a clade of now-extinct giraffids containing both sivatheres, the largest known giraffids, and samotheres, whose appearance was somewhere in between that of okapis and giraffes. All giraffids in this group feature four horn-like skull protuberances known as ossicones, two over the eyes and two larger ridged ossicones at the back of its head. The authors state that Decennatherium was likely the earliest-evolving example of this ossicone layout.

The inclusion of Decennatherium in the sivathere-samothere clade would extend its timespan back to the early late Miocene and its range as far as the Iberian peninsula, making the clade one of the most successful and long-lived of all the giraffids.

As Ríos summarizes: “New four horned extinct giraffid Decennatherium rex from Cerro de los Batallones (9my, Madrid) sheds light on the evolution of the giraffid family and the extinct giant Sivatherium.”

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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.

First fossil botfly discovery


Mesembrinella caenozoica sp. nov. Credit: Cerretti et al (2017)

From ScienceDaily:

New fly fossil sheds light on the explosive radiation of flies during the Cenozoic Era

The Cretaceous-Paleogene extinction event is linked to this fly diversification

August 23, 2017

The first unambiguous fossil from the botfly family adds to the few known fossils of a major clade of flies (Calyptratae), shedding light on their rapid radiation during the Cenozoic Era, according to a study published August 23, 2017 in the open-access journal PLOS ONE by Pierfilippo Cerrito from Sapienza Università di Roma, Italy, and colleagues.

The bot fly family (Oestroidea) is the most diverse group of calyptrate flies, which is a clade of some 22,000 living species that comprise about 14% all flies. Calyptrates arose during the Cenozoic, in what was the most rampant radiation of flies ever and among the largest radiations of insects during this era. The clade includes some of the most diverse and ecologically important families of flies: tsetse, louse, and bat flies; house flies and relatives; and blow flies, bot flies, flesh flies, and relatives. Abundant in most terrestrial ecosystems, calyptrates often play key roles as decomposers, parasites, parasitoids, vectors of pathogen vectors, and pollinators. However, there are few reliable calyptrate fossils.

Cerretti and colleagues describe the first unambiguous oestroid fossil: a new species of fly (Mesembrinella caenozoica) discovered in amber from the Dominican Republic. The researchers also used the few known calyptrate fossils as calibration points for a molecular phylogeny to estimate the timing of major radiations in this clade.

The researchers estimate that the most recent common ancestor of today’s calyptrate flies lived about 70 million years ago — that is, just before the Cretaceous-Paleogene boundary; that the radiation of oestroids began about 50 million years ago; and that the family M. caenozoica belongs to (Mesembrinellidae) originated about 40 million years ago. Importantly, the Cretaceous-Paleogene extinction event played a role in major radiations of birds, mammals and angiosperms — and this work suggests that it may also have been crucial to boosting calyptrate diversification during the Cenozoic.

See also here.

Fossil baleen whale discovery in Japan


This video says about itself:

22 August 2017

Fossil of whale of 15 million years old reveals ancient hatcheries

A second close look at a fossil has revealed a hatchery previously unknown of an extinct whale, and potentially sheds light on how species respond to changing weather conditions. They report a careful reexamination of several fossils of an extinct whale, Parietobalaena yamaokai, which existed around 15 million years ago. Fossils had been collected over the last century from around Hiroshima, and were held at Hiwa City Museum of Natural History. When examining one of the exhibits, part of a skull, Tsai noticed that two of the bones had not completely woven, indicating that the animal must have been less than six months old when he died.

Identification of a possible breeding place of the Miocene for whales in the northern hemisphere also raises some interesting questions, he concludes. When, where and what species of whales initiated the long, annual migration between feeding and childbirth. Answers to these questions could help provide clues about the breeding grounds of modern whales whose locations are largely unknown. This, in turn, will have direct application for conservation strategies.

From ScienceDaily:

A potential breeding site of a Miocene era baleen whale

Researcher identifies evidence of a calf whale from the Miocene of Hiroshima, Japan suggesting the earliest known site for baleen whale breeding in the northern hemisphere

August 22, 2017

Baleen whales are amongst the largest animals to have ever lived and yet very little is known about their breeding habits. One researcher’s second look at previously found baleen whale fossils from Japan provides new evidence of a now long-gone breeding ground of the extinct baleen whale Parietobalaena yamaokai dating back over 15 million years.

The research published in the open-access journal PeerJ elaborates on the evidence of the presence of a very young individual of an extinct baleen whale, along with the occurrence of several fossil specimens of the same whale species. This study claims to have discovered a very uncommon case — a breeding ground for a long extinct large whale.

Researcher Cheng-Hsiu Tsai noticed the open suture in the skull of one fossil specimen, which indicates the preservation of a very young whale — under six months old, perhaps even close to a new-born calf. The fossil specimens investigated were originally found in the 20th century and are currently held at the Hiwa Museum for Natural History, Shobara, Hiroshima, Japan.

Identifying breeding grounds of living species of whales are incredibly rare, let alone for extinct Miocene species. For example, scientists are not certain where the endangered western gray whales reproduce, in turn leading to no concrete strategies to recover this critically endangered population of around 100 individuals.

The discovery of an ancient paleo-breeding site, which dates back to 15 million years ago, could provide new insights into the future of baleen whale survival. In a rapidly changing world, locating breeding sites and understanding why a breeding site disappeared may subsequently lead to information on how best to respond in order to conserve these living endangered populations.

Fossil ape discovery in Kenya


Kenyan fossil hunter John Ekusi found the fossil ape infant skull jutting from the Turkana Basin’s rocky terrain. Isaiah Nengo, photo by Christopher Kiarie

From Science:

Ancient infant ape skull sheds light on the ancestor of all humans and living apes

By Michael Price

Aug. 9, 2017, 1:00 PM

Anthropologists have waited decades to find the complete cranium of a Miocene ape from Africa—one that lived in the hazy period before the human lineage split off from the common ancestors we share with chimpanzees some 7 million years ago. Now, scientists in Kenya have found their prize at last: an almost perfectly preserved skull roughly the size of a baseball. The catch? It’s from an infant. That means that although it can give scientists a rough idea of what the common ancestor to all living apes and humans would have looked like, drawing other meaningful conclusions could be challenging.

“This is the sort of thing that the fossil record loves to do to us,” says James Rossie, a biological anthropologist at the State University of New York in Stony Brook who wasn’t involved with the study. “The problem is that we learn from fossils by comparing them to others. When there are no other infant Miocene ape skulls to which to make those comparisons, your hands are tied.”

The remarkably complete skull was discovered in the Turkana Basin of northern Kenya 3 years ago. As the sun sank behind the Napudet Hills west of Lake Turkana, primate paleontologist Isaiah Nengo of De Anza College in Cupertino, California, and his team started walking back to their jeep. Kenyan fossil hunter John Ekusi raced ahead to smoke a cigarette. Suddenly he began circling in place. When Nengo caught up, he saw a dirt-clogged eye socket staring up at him. “There was this skull just sticking out of the ground,” Nengo recalls. “It was incredible because we had been going up and down that path for weeks and never noticed it.”

The young ape was about 16 months old when it died. Nyanzapithecus alesi is the name of this new species.

Fossil otter discovery in Mexico


This video says about itself:

28 February 2017

Researchers have uncovered the remains of a giant otter in China that when alive would have been comparable to the size of a wolf.

The fossils belong to a new species of ancient otter, known as Siamogale melilutra, that lived in freshwater lakes around 6 million years ago.

From the University at Buffalo in the USA:

Ancient otter tooth found in Mexico suggests mammals migrated across America

June 14, 2017

Summary: An ancient otter tooth recently discovered in Mexico suggests certain mammals migrated across America during the Miocene geologic epoch, roughly 23 million to 5.3 million years ago. The new hypothesized route questions other theories such as migrations above Canada and through Panama, and has implications for a much larger biologic event — the Great American Biotic Interchange, when land bridges were formed and animals dispersed to and from North America and South America.

Late in the afternoon on a hot March day in central Mexico, a paleontologist uncovered a jaw bone and called over to Jack Tseng.

Tseng, PhD, assistant professor in the Department of Pathology and Anatomical Sciences in the Jacobs School of Medicine and Biomedical Sciences at the University at Buffalo, was on the dig researching intercontinental immigration of fossil mammals.

“I thought it was a badger,” Tseng said, “but a colleague on the site had just finished a study of otters, and he said it was sea otter-like. But what would a sea otter be doing in central Mexico?”

Turns out the otter, from about 6 million years ago, may have been part of an immigration event from Florida to California. Based on the discovery, Tseng and his colleagues have written a paper to be published June 13 in the journal Biology Letters. They propose a new east-west passage for the otter, and potentially other mammals, along the northern edge of the Trans-Mexican Volcanic Belt, which runs across the country at the latitude of Mexico City.

“This is an entirely new idea that no one else has proposed,” Tseng said. “We think it’s very likely other animals utilized this route.”

The right tooth

Like many breakthroughs, this one came from a fortunate tiny detail. The jawbone held several teeth.

“One tooth was a lower first molar, the most diagnostic tooth in a carnivore,” Tseng said. “If we are lucky enough to find a fossil molar tooth that is complete, there is a lot of useful information.”

The tooth was almost identical to a tooth from another Enhydritherium terraenovae (an ancient sea otter) fossil found in Florida. Similar finds had only been made along the coasts, in Florida and California, but paleontologists did not know how the animals got across the continent. One hypothesis was that they moved up and around through northern Canada, an 8,000 kilometer trip. Another was they made it down to Panama and crossed over to the west.

The possibility of an east-west migratory route in Mexico in the Miocene geologic epoch (roughly 23 million to 5.3 million years ago) has implications for a much larger biologic event — the Great American Biotic Interchange, when land bridges were formed and animals dispersed to and from North America and South America. It shows that the region’s fossil sites could have recorded details of this biological interchange of historic proportions.

But why don’t we know more about this already?

“Compared to the U.S., Mexico is a blank slate in terms of paleontology,” Tseng said. The region is difficult to work in because of the topography and flora, like cactus. So not many long-term field projects exist there.

“This is the beginning of the study,” Tseng said. “Now that we have this evidence of these animals moving through Mexico, we can now look for evidence of other animals doing the same.”

Expanding ranges

Adolfo Pacheco-Castro, a PhD student at the Universidad Nacional Autonoma de Mexico, Centro de Geociencias, and an author of the study, found the jawbone at the dig site in the Juchipila Basin, about 535 miles southeast of Laredo, Texas. The bone was taken to the university in Mexico, cleaned off and studied.

“We compared it to the original tooth from Florida, based on the cusps and the size, it couldn’t be anything else,” Tseng said. The fossils in Florida are older than those in California, so researchers speculate that immigrations went east to west.

But why did they travel at all?

“Animals tend to expand their range when and where there is opportunity,” Tseng said. “As in when there is a geographic connection to suitable habitats. So as populations expand their range, they can move across a continent, or even between continents.”

The Miocene-Pliocene transitional period was a time of disturbance, Tseng said. The plains of America would have been like Africa, with many large mammals. But the first ice age was approaching.

Many large mammals perished in the ice age from environmental and anthropogenic causes, but relatives of the smaller Enhydritherium — about the size of a small to medium dog — survived into modern times and still live around central Mexico today.

New area of study

Tseng said he expects some people will not agree with the new interpretation of an east-west corridor through Mexico for other mammals. But more research may confirm it.

“We are aware it is a single discovery,” he said. “It essentially opens up a can of worms. We are throwing a different factor in. We now have a connection between Florida and California, and it’s not in a straight line.”

A massive, wolf-sized otter that lived about 6 million years ago may have been a dominant predator in its time, according to a new analysis of the animal’s jaws. When scientists used computers to simulate how biting would strain S. melilutra’s jaws, they concluded that the animal had much firmer jaw bones than expected, giving it a surprisingly strong bite: here.

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.”