Mariana Ruiz Villarreal via Wikimedia Commons // Public Domain
Mariana Ruiz Villarreal via Wikimedia Commons // Public Domain

Paleontologists Try to Diagnose a Dinosaur Skin Disease

Mariana Ruiz Villarreal via Wikimedia Commons // Public Domain
Mariana Ruiz Villarreal via Wikimedia Commons // Public Domain

Little craters on dinosaur bones aren’t necessarily battle scars from a death match. They might be signs of a less glamorous aspect of prehistoric life: festering infections.

Several years ago, a graveyard of more than 30 Gastonia ankylosaurs was discovered in Utah. When these tank-like dinosaurs died 125 million years ago, they left behind thousands of osteoderms—the bony plates of armor in their skin. Paleontologists noticed that the pieces of Gastonia armor were often marked with little pits and craters. One of the researchers, Kenneth Carpenter, curator at the Utah State University-Eastern Prehistoric Museum, said it was actually easy to tell that these weren’t bite marks.

“A pointed tooth puncturing a bone crushes and collapses the bone inward at the injury,” Carpenter told mental_floss. “This causes cracks to radiate outwards from the puncture. We did not seen any of these features on the ankylosaur armor.”

In a new study, published last month in the International Journal of Paleopathology, Carpenter and his colleagues tried to figure out what ailed the ankylosaurs by turning to a modern analog: crocodiles. The researchers looked over the literature on the bacterial infections, fungal infections, and other skin diseases than can leave traces in crocodile armor. 

Without soft tissue, a conclusive diagnosis for the ankylosaurs wasn’t possible. But Carpenter and his colleagues think a likely explanation is that some of these dinosaurs had ulcerative dermatitis—which, among snake and reptile owners today, is better known as scale rot. (The squeamish—who should probably not watch this video—can at least take comfort in the fact that dinosaurs, like birds and reptiles, likely didn’t produce liquid pus, as the study authors note.) Dinosaur dermatitis probably formed from a bacterial or fungal infection, and possibly it was a secondary infection initiated by a bite from a blood-sucking parasite, the researchers said.

“In general, not much is known about disease in dinosaurs, because most of what we have are the bones,” Carpenter said, adding that paleontologists know “practically nothing” about dinosaur skin disease because the actual skin is rarely preserved. He is only aware of one example of direct evidence for an ulcerative dermatitis lesion in a dinosaur, preserved in an impression of hadrosaur skin that was display as a touch specimen in the Utah Museum of Natural History. (Because of its rarity, it has since been pulled from the touch display, Carpenter said.)   

“Existing animals have these minor infections very commonly, like athletes foot in humans,” said Elizabeth Rega, a dinosaur disease expert at Western University of Health Sciences, who was not involved in the new study. Rega told mental_floss that researchers like herself are increasingly attributing these holes not to bites but to mundane infections. 

“But,” she added, these explanations “are routinely ignored by the media whenever someone waves [their] arms about dinosaur bite marks, because combat is so much more fun.” 

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Whale Sharks Can Live for More Than a Century, Study Finds
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Some whale sharks alive today have been swimming around since the Gilded Age. The animals—the largest fish in the ocean—can live as long as 130 years, according to a new study in the journal Marine and Freshwater Research. To give you an idea of how long that is, in 1888, Grover Cleveland was finishing up his first presidential term, Thomas Edison had just started selling his first light bulbs, and the U.S. only had 38 states.

To determine whale sharks' longevity, researchers from the Nova Southeastern University in Florida and the Maldives Whale Shark Research Program tracked male sharks around South Ari Atoll in the Maldives over the course of 10 years, calculating their sizes as they came back to the area over and over again. The scientists identified sharks that returned to the atoll every few years by their distinctive spot patterns, estimating their body lengths with lasers, tape, and visually to try to get the most accurate idea of their sizes.

Using these measurements and data on whale shark growth patterns, the researchers were able to determine that male whale sharks tend to reach maturity around 25 years old and live until they’re about 130 years old. During those decades, they reach an average length of 61.7 feet—about as long as a bowling lane.

While whale sharks are known as gentle giants, they’re difficult to study, and scientists still don’t know a ton about them. They’re considered endangered, making any information we can gather about them important. And this is the first time scientists have been able to accurately measure live, swimming whale sharks.

“Up to now, such aging and growth research has required obtaining vertebrae from dead whale sharks and counting growth rings, analogous to counting tree rings, to determine age,” first author Cameron Perry said in a press statement. ”Our work shows that we can obtain age and growth information without relying on dead sharks captured in fisheries. That is a big deal.”

Though whale sharks appear to be quite long-lived, their lifespan is short compared to the Greenland shark's—in 2016, researchers reported they may live for 400 years. 

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Animal Welfare Groups Are Building a Database of Every Cat in Washington, D.C.
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There are a lot of cats in Washington, D.C. They live in parks, backyards, side streets, and people's homes. Exactly how many there are is the question a new conservation project wants to answer. DC Cat Count, a collaboration between Humane Rescue Alliance, the Humane Society, PetSmart Charities, and the Smithsonian Conservation Biology Institute, aims to tally every cat in the city—even house pets, The New York Times reports.

Cities tend to support thriving feral cat populations, and that's a problem for animal conservationists. If a feline is born and grows up without human contact, it will never be a suitable house cat. The only options animal control officials have are to euthanize strays or trap and sterilize them, and release them back where they were found. If neither action is taken, it's the smaller animals that belong in the wild who suffer. Cats are invasive predators, and each year they kill billions of birds in the U.S. alone.

Before animal welfare experts and wildlife scientists can tackle this problem, they need to understand how big it is. Over the next three years, DC Cat Count will use various methods to track D.C.'s cats and build a feline database for the city. Sixty outdoor camera traps will capture images of passing cats, relying on infrared technology to sense them most of the time.

Citizens are being asked to help as well. An app is currently being developed that will allow users to snap photos of any cats they see, including their own pets. The team also plans to study the different ways these cats interact with their environments, like how much time pets spend indoors versus outdoors, for example. The initiative has a $1.5 million budget to spend on collecting data.

By the end of the project, the team hopes to have the tools both conservationists and animal welfare groups need to better control the local cat population.

Lisa LaFontaine, president and CEO of the Humane Rescue Alliance, said in a statement, “The reality is that those in the fields of welfare, ecology, conservation, and sheltering have a common long-term goal of fewer free-roaming cats on the landscape. This joint effort will provide scientific management programs to help achieve that goal, locally and nationally."

[h/t The New York Times]

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