Rileycat

Bronto-queen, big cat, bestselling and award-winning author of When the Earth Was Green, The Last Days of the Dinosaurs, and Tyrant Lizard Queen (2026). she/they/it

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Carnivores aren’t welcome in the West, but their ghosts are

This time of year reminds me of when I took a road trip to visit the grave of Old Ephraim, Utah’s last grizzly, and got a giant pizza in their honor. 🐻

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Aardwolves are hyenas, but they’re not like any other living hyena species. Because they eat termites and social insects! 🐜

Like many other “ant eaters” among mammals, aardwolves have a reduced tooth count and lap up bugs with a long, sticky tongue. They also belong to their own genus, Proteles, and are the last of an ancient lineage of “running hyenas” that have been around for about 10 million years.

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Extremely Spiky Dinosaur a Reminder of Fossil Record's Surprises — Riley Black

The discovery of an ornately-armored dinosaur underscores how much we don't yet know about the "terrible lizards."

Spicomellus was named in 2021 from a single, spiky bone. Now we have a better idea of what the whole dinosaur looked like and it’s wild.

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Finding one dinosaur track is a happy circumstance. Finding a track-trampled surface is phenomenal. These particular footprints are in the 100 million-year-old rocks of Colorado’s Dinosaur Ridge, dotted with the tracks of hadrosaurs and ornithomimosaurs. When surfaces like this have been especially churned by the footfalls of dinosaurs, experts call it “dinoturbated” - a modification of the word bioturbation used for organisms that mix sediment through their behavior.

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When I was a kid we called this fish Carcharodon megalodon, thought to be a close relative of today’s great white shark (Carcharodon carcharias). But now we call it something else. The fossil teeth and vertebrae that represent this shark are called Otodus megalodon, a closer relative of today’s mako sharks than the star of JAWS. We still don’t know for sure what the shark looked like in life, though. This rendition at the National Museum of Natural History is more mako-like, but a recent paper argues O. megalodon had a more elongated, lemon snark-like profile to reduce drag. Who knows? Maybe the fossil that will resolve the debate is still out there.

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I kicked off my career as a science blogger, so why not get back to it? To get things started, I looked at a 12-foot-long fossil croc with dinosaur-like teeth.

Beautiful skeleton reveals flesh-ripping croc from the Age of Dinosaurs — Riley Black

Meet Kostensuchus, a 12-foot-long crocodile that was part of a long-lived carnivorous family.

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New dinosaur day! Meet Zavacephale, the oldest and most complete pachycephalosaur yet described. And it’s tiny, a beeper that only weighed about 10kg. I’ll tell you all about it at NatGeo.

Dome-headed dinosaurs are rare. Scientists just found the most remarkable one yet.

When did these blockhead dinosaurs get their domes? A new fossil is “the specimen we have all been waiting for.”

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Arizona’s sky islands are home to a rare orchid that’s been struggling to hang on. Dogs, fungus, bees, range cattle, and, of course, people are coming to the rescue. I’ll tell you more in my latest for Smithsonian.

This Rare, Endangered Orchid Only Exists in Two Locations. Can Dogs, Cows and Fungi Help It Thrive?

A Smithsonian ecologist is trying to restore the plant, Spiranthes delitescens, which grows on Arizona’s sky islands

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Want to see the K/Pg boundary for yourself? Check out Trinidad, CO. The line marking the disappearance of Tyrannosaurus and friends, and the beginning of the Cenozoic, is exposed along a short trail in the town. I visited in 2021 as I was writing The Last Days of the Dinosaurs with Jet, my woofer. Trinidad, CO was also called “The Sex Change Capital of the World” for being an early place transgender people could go for gender-affirming surgery.

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More than 520 million years ago, something changed on Earth. Life began a fantastic diversification, spinning off amazing new forms of every shape and size that set the basis for the world as we know it. Some call this the “Cambrian Explosion.” Others cast it as a more prolonged flourishing. Either way, the amazing flowering of life has led experts to search for why the Cambrian was such a critical time. I dig in at Smithsonian Magazine.

What Led Life to Flourish Roughly 520 Million Years Ago?

Changes to the world’s oceans and the rise of certain predators may have driven diversification

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When we say “horned dinosaurs,” we’re usually referring to ceratopsids like Triceratops and Styracosaurus. But those herbivores weren’t the only dinosaurs with horns. Over and over, theropod dinosaurs evolved horns, too, important social signals that took on a variety of shapes and orientations. The brow horns of Allosaurus fragilis are some of my favorites, conspicuous triangles that distinguished one individual from another.

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Long ago, after the asteroid that ended the Cretaceous, primates clambered and leaped through the humid forests of North America. Some were lemur-like, but others were small, big-eyed bug eaters called omomyids. These tarsier-like primates lived between 55 and 34 million years ago, more closely related to the primate lineages we came from than lemurs and galagos. This particular representation is on display at the San Diego Natural History Museum. I wish some of these cousins were still here.

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Stegosaurus is an iconic Jurassic dinosaur, one of the most distinctive reptiles in North America’s Morrison Formation. You can see some of their bones at Dinosaur National Monument, Utah, as well as this charming sculpture. The restoration is the same Stegosaurus as the one put on display by the fossil fuel company Sinclair as part of their “Dinoland” in the 1964-65 New York World’s Fair.

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We don’t have very many Tyrannosaurus rex baby fossils, but “Chomper” is among the few. This reconstruction at the Museum of the Rockies is a hypothesis, based on a few associated skull pieces. Just look at those big eyes, aw.

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Direct evidence of combat is rare in the fossil record, but a handful of Smilodon skulls - both from La Brea in Los Angeles and Pleistocene sites in South America - show how Ice Age cat fights played out. Several Smilodon crania show punctures through the roof of the skull that match the saber canines of other Smilodon. The pattern is consistent with injuries seen in some other sabertooths, like the cat-like nimravids, a case of combat convergence that may have been emerged from evolving saber teeth. The strange part is that saber canines are usually flattened and knife-like, not very good against twisting forces and relatively fragile, but apparently all bets were off when it came in sabertooth versus sabertooth fights.

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Most of the skeletons on display at La Brea are composites, pieced together from elements of many individual animals. (With rare exception, associated and articulated skeletons are not found in the sticky jumble of La Brea.) Sometimes the kitbash is obvious, like this dentary of Camelops, the giant camel, that’s a touch too big for the cranium. See how the rear process of the jaw sticks up so high it looks like a horn? Yep.

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Skulls are pretty and all, but sometimes the most distinctive parts of a dinosaur are other skeletal elements. See this collection of ribs around a tall, t-shaped vertebra? That’s a dead giveaway these associated bones are from a Stegosaurus, preserved on the left hand side of Dinosaur National Monument, Utah. The tall neural spines helped give Stegosaurus its characteristic hump-backed look, the plates growing in the skin.

I’m envious.