Tag Archives: Panama

Crocodile, mammal fossil discoveries in Panama

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A life reconstruction of Culebrasuchus mesoamericanus, one of two newly discovered species from the early Miocene in Panama / Danielle Byerley/ Florida Museum of Natural History

From the University of Florida in the USA:

Scientists Discover New Crocodilian, Hippo-Like Species From Panama

University of Florida paleontologists have discovered remarkably well-preserved fossils of two crocodilians and a mammal previously unknown to science during recent Panama Canal excavations that began in 2009.

The two new ancient extinct alligator-like animals and an extinct hippo-like species inhabited Central America during the Miocene about 20 million years ago. The research expands the range of ancient animals in the subtropics — some of the most diverse areas today about which little is known historically because lush vegetation prevents paleontological excavations — and may be used to better understand how climate change affects species dispersal today. The two studies appear online today in the same issue of the Journal of Vertebrate Paleontology.

The fossils shed new light on scientists’ understanding of species distribution because they represent a time before the formation of the Isthmus of Panama, when the continents of North and South America were separated by oceanic waters.

“In part we are trying to understand how ecosystems have responded to animals moving long distances and across geographic barriers in the past,” said study co-author Jonathan Bloch, associate curator of vertebrate paleontology at the Florida Museum of Natural History on the UF campus. “It’s a testing ground for things like invasive species – if you have things that migrated from one place into another in the past, then potentially you have the ability to look at what impact a new species might have on an ecosystem in the future.”

The research was funded by the National Science Foundation Panama Canal Partnerships in International Research and Education project, which supports paleontological excavation of the canal during construction expected to continue through 2014.

“We’re very fortunate we could get the funding for PIRE to take advantage of this opportunity — we’re getting to sample these areas that are completely unsampled,” said Alex Hastings, lead author of the crocodilian study and a visiting instructor at Georgia Southern University who conducted the research for the project as a UF graduate student.

Researchers analyzed all known crocodilian fossils from the Panama Canal, including the oldest records of Central American caimans, which are cousins of alligators. The more primitive species, named Culebrasuchus mesoamericanus, may represent an evolutionary transition between caimans and alligators, Hastings said.

“You mix an alligator and one of the more primitive caimans and you end up with this caiman that has a much flatter snout, making it more like an alligator,” Hastings said. “Before this, there were no fossil crocodilian skulls known from Central America.”

Christopher Brochu, an assistant professor of vertebrate paleontology in the department of geoscience at the University of Iowa, said “the caiman fossil record is tantalizing,” and the new data shows there is still a long way to go before researchers understand the group.

“The fossils that are in this paper are from a later time period, but some of them appear to be earlier-branching groups, which could be very important,” said Brochu, who was not involved with the study. “The problem is, because we know so little about early caiman history, it’s very difficult to tell where these later forms actually go on the family tree.”

The new mammal species researchers described is an anthracothere, Arretotherium meridionale, an even-toed hooved mammal previously thought to be related to living hippos and intensively studied on the basis of its hypothetical relationship with whales. About the size of a cow, the mammal would have lived in a semi-aquatic environment in Central America, said lead author and UF graduate student Aldo Rincon.

“With the evolution of new terrestrial corridors like this peninsula connecting North America with Central America, this is one of the most amazing examples of the different kind of paths land animals can take,” Rincon said. “Somehow this anthracothere is similar to anthracotheres from other continents like northern Africa and northeastern Asia.”

Researchers also name a second crocodilian species, Centenariosuchus gilmorei, after Charles Gilmore, who first reported evidence of crocodilian fossils collected during construction of the canal 100 years ago. The genus is named in honor of the canal’s centennial in 2014.

Researchers will continue excavating deposits from the Panama Canal during construction to widen and straighten the channel and build new locks. The project is funded by a $3.8 million NSF grant to develop partnerships between the U.S. and Panama and engage the next generation of scientists in paleontological and geological discoveries along the canal.

Study co-authors include Bruce MacFadden of UF and Carlos Jaramillo of the Smithsonian Tropical Research Institute.

Related articles

Rodents’ takeover from elephants in Panamanian rainforests

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This video is called Movement paths of 224 radio-tagged palm seeds by rodents on Barro Colorado Island, Panama.

It says about itself:

Relative movement paths of 224 radio-tagged palm seeds handled by rodents on Barro Colorado Island, Panama. Colored dots mark locations of 129 seeds that were found eaten (orange), 86 seeds last seen before they lost their tags (gray), and 9 seeds that were still alive, cached, and being monitored after a year (pink).

Smithsonian Tropical Research Institute, Panama. By attaching tiny radio transmitters to more than 400 seeds, Patrick Jansen, scientist at the Smithsonian Tropical Research Institute and Wageningen University, and his colleagues found that 85 percent of the seeds were buried in caches by agoutis, common, house cat-sized rodents in tropical lowlands. Agoutis carry seeds around in their mouths and bury them for times when food is scarce.

By Ajai Raj:

Thieving rodents saved tropical palm

Monday, 16 July 2012

SYDNEY: An innovative seed-tracking study in the Panamanian rainforest has solved the mystery of how the black palm tree spreads its seeds.

Until now, how the black palm (Astrocaryum standleyanum), a spiny palm trees native to Central and South America, dispersed its seeds has been a mystery. Its seeds, big and heavy compared to other seeds, were likely once eaten by enormous megafauna, which later pooed out the seeds further afield. However, the last of these went extinct at the end of the Pleistocene epoch, over 10,000 years ago – so how is the tree still here?

To figure it out, researchers used an innovative seed-tracking study, radio-tagging about 600 black palm tree seeds and placing them at stations across Barro Colorado Island, which were monitored with motion-sensitive cameras.

Seed stolen and moved 36 times

What they found surprised them: agoutis (Dasyprocta punctata), a widespread South American rodent species, dug up the seeds of the black palm and, instead of eating them, moved them to another location and re-buried them. One seed they tracked was moved 36 times over 209 days, travelling 749 meters and ending up 280 meters from where it began, according to a study published in the Proceedings of the National Academy of Sciences.

From the National Science Foundation in the USA:

Thieving Rodents: Did They Save Tropical Trees?

Rodents may have taken over seed-dispersal role of now-extinct mammals.

Big seeds produced by tropical trees such as black palms were probably once ingested and then left whole by huge mammals called gomphotheres.

Gomphotheres weighed more than a ton and dispersed the seeds over large distances.

But these Neotropical creatures disappeared more than 10,000 years ago. So why aren’t large-seeded plants also extinct?

A paper published this week in the journal Proceedings of the National Academy of Sciences (PNAS) suggests that rodents may have taken over the seed-dispersal role of gomphotheres.

“The question has been: how did a tree like the black palm manage to survive for 10,000 years, if its seed-dispersers are extinct?” asks Roland Kays, co-author of the paper and a zoologist at North Carolina State University and the North Carolina Museum of Natural Sciences.

“This research solves a long standing puzzle in ecology,” says Alan Tessier, program director in the National Science Foundation’s (NSF) Division of Environmental Biology, which funded the research.

“How did plant species that seem to be dependent on Pleistocene megafauna for seed-dispersal survive the extinction of that megafauna?”

Now, says Kays, scientists may have an answer.

By attaching tiny radio transmitters to more than 400 seeds, Patrick Jansen, a scientist at the Smithsonian Tropical Research Institute (STRI) and Wageningen University and colleagues found that 85 percent of the seeds were buried in caches by agoutis, common rodents in tropical lowlands.

Agoutis carry seeds around in their mouths and bury them for times when food is scarce.

Radio-tracking revealed a surprising finding: when the rodents dig up the seeds, they usually don’t eat them, but instead move them to a new site and bury them, often many times.

One seed in the study was moved 36 times.

Researchers used remote cameras to catch the animals digging up cached seeds. They discovered that frequent seed movement primarily was caused by animals stealing seeds from one another.

Ultimately, 35 percent of the seeds ended up more than 100 meters from their origin. “Agoutis moved seeds at a scale that none of us had ever imagined,” says Jansen.

“We had observed seeds being moved and buried up to five times, but in this system it seems that re-caching behavior is ‘on steroids,’” says Ben Hirsch of STRI and Ohio State University.

“By radio-tagging the seeds, we were able to track them as they were moved by agoutis, find out if they were taken up into trees by squirrels, then discover the seeds inside spiny rat burrows.

“That allowed us to gain a much better understanding of how each rodent species affects seed dispersal and survival.”

By taking over the role of Pleistocene mammals in dispersing large seeds, thieving, scatter-hoarding agoutis may have saved several species of trees from extinction.

See also here. And here.

New Panamanian frog discovered

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This video is about Panamanian golden frogs.

From Wildlife Extra:

New frog species from Panama will turn your fingers yellow

New species of rain frog from Panama

May 2012. A new bright yellow frog species has been found in the mountains of western Panama. The frog belongs to a species-rich group of frogs, the so called rainfrogs that lack a tadpole stage, but develop directly as little frogs inside the egg.

Just 2cms long

The frog, that measures less than 2 cm, was discovered by Andreas Hertz and his colleagues, who are reptile and amphibian specialists at the Senckenberg Research Institute in Frankfurt am Main; Germany. They discovered it in 2010 during several field trips to the Serranía de Tabasará of western Panama a highly understudied part of the Panamanian central mountain range.

“Although we recognized that the male mating call of this species differs from all that we had heard before and therefore suspected it to be new, much effort was involved to finally spot it in the dense vegetation”, said Hertz. “When we finally caught the first individuals by hand, we noticed that it dyes one’s fingers yellow when it is handled. The scientific name (Diasporus citrinobapheus) of this new frog refers to this characteristic and means yellow dyer rainfrog.”

To assure the validity of the frog as a new species, the biologists studied body structure, colouration, molecular genetic data, and vocalizations of a series of individuals, and compared the results with the data derived from closely related species.

Yellow dye

Additionally, the researchers took into consideration the possibility that the yellow stain may be poisonous and performed an analysis of skin secretions. “We cannot say whether the dye is any good as a predatory defence, as we could not find any poisonous components. Maybe the colour is just easily washed out and has no particular function. However, for now, this peculiarity of the new species remains enigmatic.” said Hertz.

Most of the more than 6,000 species of frogs in the world lay their eggs in water. But many tropical frogs lay their eggs out of water. This behavior protects the eggs from aquatic predators, such as fish and tadpoles, but also increases their risk of drying out. Justin Touchon, post-doctoral fellow at the Smithsonian Tropical Research Institute, discovered that climate change in Panama may be altering frogs’ course of evolution: here.

Endangered Panamian sloths, new research

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This video is called Pygmy three-toed sloth swimming HD.

From Wildlife Extra:

First population census of Critically Endangered pygmy three-toed sloth

In search of the pygmy sloth

May 2012. A group of tiny sloths living on an uninhabited island will finally counted, after a team from the Zoological Society of London (ZSL) conducted the first ever population census of the pygmy three-toed sloth (Bradypus pygmaeus).

Only found on 1 small island

The team undertook a nine-day expedition to Escudo Island, 17km off the coast of Panama, which is the only place in the world where the sloths are found. There, they conducted the first detailed population and habitat survey of the area, and spent time monitoring the unique behaviours of the world’s slowest mammal.

16th most endangered mammal

At half the size of their mainland cousins, and weighing roughly the same as a newborn baby, pygmy sloths are the smallest and slowest sloths in the world. They are ranked at number 16 on the EDGE of Existence mammals list and remain critically endangered.

ZSL’s David Curnick says: “Very little is known about this species. Current population estimates are, at a best guess, less than 500, but this is only based on anecdotal evidence. We’ve collected data for the first time to get an accurate picture of how many pygmy sloths are left in the world.”

More endemic species

Escudo is an unpopulated island fringed by mangrove forests, and roughly the size of New York’s Central Park. As well as sloths, it is known to be home to several other endemic species, including the neotropical fruit bat (Artibeus incomitatus) and the maritime worm salamander (Oedipina maritime), but very little is known about its wildlife, and the island remains largely unexplored.

As well as using bromeliad leaves as an umbrella to protect themselves from extreme weather, pygmy sloths appear to use mangrove trees as a tool to regulate their body temperatures – on cooler days they climb to higher spots to catch the sun, and when they get too hot they head down again to find a shadier spot.

Maybe fewer than 100 left alive

The team’s current data suggests that there could be fewer than 100 pygmy sloths left, making them one of the most endangered mammals in the world. The exact reasons for this decline are not yet known, but they found several areas where their critical mangrove habitats have been cut down.

Dr. Craig Turner from ZSL added: “The mangrove forests are relatively hard to penetrate, and from a sloth’s perspective they provide protection from aerial predators. We noticed that pygmy sloth mothers carrying young would remain low in trees, which may be an evolutionary hangover for predator evasion. However, hunting, mangrove cutting and tourism are all listed as threats to these sloths and their behaviour may now be putting them at higher risk.”

Conservationists from ZSL are currently analysing their data, and aim to publish the findings in the next few months. The team hopes to appoint and train an in-country EDGE fellow later in the year, and they will continue their monitoring and work within the local communities to establish the main threats to the species and develop plans to protect them.

Pygmy Three-Toed Sloth

The pygmy three-toed sloth was only recognised as a distinct species in 2001. It can only be found on Isla Escudo de Veraguas, which has been separated from mainland Panama for 9,000 years. Famous for its slow movements the pygmy three-toed sloth is ideally suited to life in the mangroves and is surprisingly good at swimming. The major threat to the pygmy three-toed sloth is habitat destruction which is reducing the size of its already small habitat.

Panamanian crocodile-like camel fossils discovered

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This video from the USA says about itself:

Fossilized camel toe bone unearthed during Florida training dig for OVIASC members.

By Jennifer Viegas:

Fossils of Crocodile-Like Camel Found

Mon Mar 5, 2012

Camels with long, crocodile-like snouts once lived near what is now the Panama Canal, suggests a new study.

The camels lived 20 million years ago and are now considered to be among the oldest known animals from Panama.

“They were probably browsers in the forests of the ancient tropics. We can say that because the crowns are really short,” lead author Aldo Rincon, a University of Florida geology doctoral student, said in a press release.

Rincon and his team are working with the Panama Canal Authority and scientists at the Smithsonian Tropical Research Institute to make the most of a five-year window of excavations during Panama Canal expansions that began in 2009.

The new fossil camels, Aguascalietia panamaensis and Aguascalientia minuta, extend the distribution of mammals to their southernmost point in the ancient tropics of Central America.

Excavations are often difficult in the tropics because the lush vegetation prevents access. That’s not such a bad thing, considering that these species-rich areas contain some of the world’s most important ecosystems, including rain forests that regulate climate systems and serve as a vital source of food and medicine.

“We’re discovering this fabulous new diversity of animals that lived in Central America that we didn’t even know about before,” said co-author Bruce MacFadden, vertebrate paleontology curator at the Florida Museum on the UF campus and co-principal investigator on the NSF grant funding the project.

“The family originated about 30 million years ago and they’re found widespread throughout North America, but prior to this discovery, they were unknown south of Mexico.”

The two new fossil camels, found in the Las Cascadas formation, belong to an evolutionary branch of the camel family separate from the one that gave rise to modern camels.

Camels belong to a group of even-toed ungulates that includes cattle, goats, sheep, deer, buffalo and pigs. Other fossil mammals discovered in Panama from the early Miocene have been restricted to those also found in North America at the time.

While researchers are sure the ancient camels were herbivores that likely browsed in forests, they are still analyzing seeds and pollen to better understand the environment of the ancient tropics.

“People think of camels as being in the Old World, but their distribution in the past is different than what we know today,” MacFadden said. “The ancestors of llamas originated in North America and then when the land bridge formed about four to five million years ago, they dispersed into South America and evolved into the llama, alpaca, guanaco and vicuña.”

The study was published in the latest Journal of Vertebrate Paleontology.

See also here.

The feeding habits of mammals haven’t always been what they are today, particularly for omnivores, finds a new study. Some groups of mammals almost exclusively eat meat — take lions and tigers and other big cats, for example. Other mammals such as deer, cows and antelope are predominantly plant-eaters, living on a diet of leaves, shoots, fruits and bark. But particularly for omnivores that live on plant foods in addition to meat, the situation wasn’t always that way, finds a new study by researchers working at the National Evolutionary Synthesis Center in Durham, North Carolina: here.

New American bee species discovered

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This video is called Stingless bee watching you (Melipona titania).

From Wildlife Extra:

Two new bee species are mysterious pieces in the Panama puzzle

Can these tiny bees unlock history of tectonic plate movements?

October 2011: Two new, closely related bee species: one from Coiba Island in Panama and another from northern Colombia have been discovered by Smithsonian scientists.

Both species descended from of a group of stingless bees that originated in the Amazon and moved into Central America, the ancestors of Mayan honeybees.

The presence of one of these new species on Coiba and Rancheria Islands, and its absence from the nearby mainland, is a mystery that may ultimately shed light on Panama’s history and abundant biodiversity.

At almost 200 square miles, Coiba Island is the largest offshore island along the Pacific coast of Latin America. Rancheria Island is a much smaller neighbour. The species name, insularis, of the new bee from Coiba, means ‘island’. This is the first species in its group to be found on islands near the mainland.

These bees have a small range

‘These forest bees have a small range over which they can establish new nests and colonies,’ says David Roubik, staff scientist at the Smithsonian Tropical Research Institute. ‘They can’t establish a new nest across more than a short stretch of open water because workers from the original nest have to build and supply the new nest before the new queen moves in.’

Either several entire tree-cavity nests arrived on Coiba and Rancheria in floating mats of vegetation or a land connection existed between the island and the mainland before the bees disappeared from the mainland.

Sea level has risen and fallen dramatically in the past. During ice ages, sea level dropped in Panama. Five other stingless bee species on Coiba are widespread on the mainland and on many little islands that were connected to the mainland during glaciations.

Panama land bridge could have arisen millions of years earlier than thought

Those bees are relative newcomers that may have arrived during past drops in sea level when the islands were reconnected to the mainland.

But even if a drop in sea level explains how the bees got from the mainland to the island, their discovery that the bees had already established in Central America around 17 million years ago spurs an ongoing debate about the age of the connection between North and South America. Traditionally, geologists think that the Panama land bridge arose by tectonic and volcanic action to connect the two continents about three million years ago.

‘Our studies of the genetic relationships between these bees tells us that they originated in the Amazon about 22 million years ago and that they moved north into Central America before three million years ago,’ said Roubik. ‘This actually agrees with new evidence that geologists working in the earthworks created by the Panama Canal expansion project are finding. We think that a land bridge may have formed as early as 12 million years ago.’

See also here.

USDA Ignores Pesticide Ravaging Bee Population, Threatening Global Environment. Mike Barrett, Natural Society: “There has been a great deal of cover up and secrecy regarding the ongoing bee deaths, enraging environmentalists and activists alike…. The USDA and EPA knew why a series of ‘mysterious’ downfalls were occurring with crops, birds, and bees. Although technological products like cell phone towers and cell phones are hurting the bee population, it was actually the pesticide brought to you by Bayer which was causing the damage, and the USDA knew of it all along”: here.

ScienceDaily (Mar. 8, 2012) — A new study in Science suggests that thrill-seeking is not limited to humans and other vertebrates. Some honey bees, too, are more likely than others to seek adventure. The brains of these novelty-seeking bees exhibit distinct patterns of gene activity in molecular pathways known to be associated with thrill-seeking in humans, researchers report: here.

Yes, Insecticides Kill Bees. Studies ID Chemical That May Contribute to Colony Collapse: here.

Pesticides cause bees to lose their bearings: here.