Drought Uncovers Dinosaur Tracks in US Park

A handout image obtained on August 23, 2022 courtesy of the Dinosaur Valley State Park shows dinosaur tracks from around 113 million years ago. Handout Dinosaur Valley State Park/AFP
A handout image obtained on August 23, 2022 courtesy of the Dinosaur Valley State Park shows dinosaur tracks from around 113 million years ago. Handout Dinosaur Valley State Park/AFP
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Drought Uncovers Dinosaur Tracks in US Park

A handout image obtained on August 23, 2022 courtesy of the Dinosaur Valley State Park shows dinosaur tracks from around 113 million years ago. Handout Dinosaur Valley State Park/AFP
A handout image obtained on August 23, 2022 courtesy of the Dinosaur Valley State Park shows dinosaur tracks from around 113 million years ago. Handout Dinosaur Valley State Park/AFP

A drought in Texas dried up a river flowing through Dinosaur Valley State Park, exposing tracks from giant reptiles that lived some 113 million years ago, an official said Tuesday.

Photos posted on Facebook show three-toed footprints leading down a dry tree-lined riverbed in the southern US state. It is "one of the longest dinosaur trackways in the world," a caption accompanying the images says.

Stephanie Salinas Garcia of the Texas Parks and Wildlife Department said dry weather made the tracks visible.

"Due to the excessive drought conditions this past summer, the river dried up completely in most locations, allowing for more tracks to be uncovered here in the park," she said.

"Under normal river conditions, these newer tracks are under water and are commonly filled in with sediment, making them buried and not as visible," AFP quoted Garcia as saying.

Most of the recently revealed tracks were made by Acrocanthosaurus, which weighed nearly seven tons (6,350 kilograms) as an adult and stood 15 feet (4.5 meters) tall.

Another dinosaur, Sauroposeidon, also left tracks in the park. It measured 60 feet tall and weighed 44 tons in adulthood.

The state park -- located in an inland area southwest of the city of Dallas -- was once on the edge of an ancient ocean, and dinosaurs left footprints in the mud, its website says.

While drought revealed the tracks, rain is in the forecast, meaning they will likely be covered once more.

"While they will soon be buried again by the rain and the river, Dinosaur Valley State Park will continue to protect these 113 million-year-old tracks not only for present, but future generations," Garcia said.



Jungle Music: Chimp Drumming Reveals Building Blocks of Human Rhythm

In this photo provided by researchers, a wild male chimpanzee produces a pant-hoot call to elicit a response from distant group members and reunite with them in the Budongo Forest of Uganda in June 2016. (Adrian Soldati via AP)
In this photo provided by researchers, a wild male chimpanzee produces a pant-hoot call to elicit a response from distant group members and reunite with them in the Budongo Forest of Uganda in June 2016. (Adrian Soldati via AP)
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Jungle Music: Chimp Drumming Reveals Building Blocks of Human Rhythm

In this photo provided by researchers, a wild male chimpanzee produces a pant-hoot call to elicit a response from distant group members and reunite with them in the Budongo Forest of Uganda in June 2016. (Adrian Soldati via AP)
In this photo provided by researchers, a wild male chimpanzee produces a pant-hoot call to elicit a response from distant group members and reunite with them in the Budongo Forest of Uganda in June 2016. (Adrian Soldati via AP)

Like humans, chimpanzees drum with distinct rhythms - and two subspecies living on opposite sides of Africa have their own signature styles, according to a study published in Current Biology.

Previous work showed chimpanzees pound the huge flared buttress roots of rainforest trees to broadcast low‑frequency booms through dense foliage.

The idea that ape drumming might hold clues to the origins of human musicality has long fascinated scientists, but collecting enough clean data amid the cacophony of the jungle had, until now, proven elusive.

“Finally we've been able to quantify that chimps drum rhythmically - they don't just randomly drum,” lead author Vesta Eleuteri of the University of Vienna told AFP.

The findings lend fresh weight to the theory that the raw ingredients of human music were present before our evolutionary split from chimpanzees six million years ago.

For the new study, Eleuteri and colleagues - including senior authors Catherine Hobaiter of the University of St Andrews in the UK and Andrea Ravignani of Sapienza University in Rome - compiled more than a century's worth of observational data.

After cutting through the noise, the team focused on 371 high-quality drumming bouts recorded from 11 chimpanzee communities across six populations living in both rainforest and savannah-woodland habitats across eastern and western Africa.

Their analysis showed that chimpanzees drum with definitive rhythmic intent - the timing of their strikes is not random.

Distinct differences also emerged between subspecies: western chimpanzees tended to produce more evenly timed beats, while eastern chimpanzees more frequently alternated between shorter and longer intervals.

Western chimps also drummed more frequently, kept a quicker tempo, and began drumming earlier in their signature chimp calls, made up of rapid pants and hoots.

The researchers do not yet know what is driving the differences - but they propose that it might signify differences in social dynamics.

The western chimps' faster, predictable pulse might promote or be evidence of greater social cohesion, the authors argue, noting that western groups are generally less aggressive toward outsiders.

By contrast, the eastern apes' variable rhythms could carry extra nuance - handy for locating or signaling companions when their parties are more widely dispersed.

Next, Hobaiter says she would like to study the data further to understand whether there are intergenerational differences between rhythms within the same groups.

“Music is not only a difference between different musical styles, but a musical style like rock or jazz, is itself going to evolve over time,” she said.

“We're actually going to have to find a way to tease apart group and intergenerational differences to get at that question of whether or not it is socially learned,” she said. “Do you have one guy that comes in with a new style and the next generation picks it up?”