The majority of living birds and mammals are smaller than the tiniest dinosaurs ever discovered. So what prevented dinosaurs from becoming truly tiny? The answer, new research suggests, may lie not in dinosaur biology, but in their ecosystems. Read more about the findings.👇

New Study Asks: “Where Are the Tiny Dinosaurs?” | AMNH

Research suggests that competition with mammals may explain why non-bird dinosaurs never evolved into truly tiny animals.

amnh.link

It's Trilobite Tuesday! Trilobites, while commonly seen fossilized as single individuals, were highly social animals—gathering together to mate, molt, or feed. On occasion, fossils are unearthed featuring multiple trilobites on a single slab, like these ornate 1-in- (2.5-cm-) long Devonian lichids.

My Photo of the Day: Taken from inside the American Museum of Natural History, #nyc #Photography

Meet the greater naked bat. Glands on this mammal's neck produce unpleasant-smelling secretions—the scent of which has been compared to “stale socks drenched in engine oil.” It can be found in colonies of ~20,000 individuals. Photo: Vatcharavee Sriprasertsil, CC BY-NC 4.0, iNaturalist

Today’s Exhibit of the Day? The Museum’s giant sequoia. When this tree was felled by a lumber company in 1891 (which is now illegal), it was 331 ft (100.1 m) tall. In 1912, this sequoia slice was cut to fit through the Museum. Visitors today can still spot the seams where it was put back together.

The new Microraptor model @amnh.org is quite nice. There is also a cast of the M. gui holotype.

It's Fossil Friday! Meet Eryops megacephalus. This critter, which lived some 280 million years ago during the Early Permian, was among the most terrestrial of the early tetrapods. Spot it in the Hall of Vertebrate Origins! Plan your visit: amnh.link/4bnMbG3 Photo: © AMNH

Meet the blunt-headed burrowing frog! Also known as the balloon frog, it spends much of its time underground. During the breeding season, it comes to the surface and takes advantage of seasonal rain pools to release up to 300 eggs. Photo: Noah Kirkland, CC BY 4.0, iNaturalist

This #InternationalTigerDay, we’re remembering the Caspian tiger. This large tiger subspecies weighed ~530 lbs (240 kg). It was driven to extinction by the same factors threatening surviving tigers—human activity, including deforestation and overhunting. Photo: Wikimedia Commons, Public Domain

It's time for Trilobite Tuesday. These 2-in- (5.1-cm-) long specimens—contained in a block of limestone from the Ordovician outcrops of Tennessee—are considered Gabriceraurus trilobites. Long viewed as an unidentified species of Ceraurus, such classifications can change based on new research.

🌈 Check out the rainbow leaf beetle! Though widely distributed across Europe, this insect is seldom seen. Growing ~0.5 in (1.3 cm) in size, it feeds on plants including ivy, roses, & thyme. This beetle inhabits montane forests at elevations of ~1970 ft (600 m). Photo: Slimguy, Wikimedia Commons

This parasitic plant smells like a rotting corpse: jackal food. Unlike many plants, which use photosynthesis, this species attaches itself to host plants & siphons off their nutrients. Its flavor & texture have been compared to that of a potato. Photo: Alex Lansdowne, CC BY-NC 4.0, iNaturalist

Happy birthday to Vera Rubin, born on this day in 1928! An acclaimed scientist, Rubin's observations established the presence of dark matter in galaxies. She was elected to the National Academy of Sciences & awarded the National Medal of Science. Photo: NOIRLab, CC BY 4.0, Wikimedia Commons

Behold the common snapping turtle! This robust reptile can weigh more than 70 lbs (31.8 kg). Its diet includes birds, small mammals, fish, and aquatic vegetation. And? It can survive for up to 30 years in the wild! Photo: Jody Benedict, CC BY-NC 4.0, iNaturalist

Cheetahs don’t have stripes, or do they? When scientists first observed the "king cheetah," it was thought to be a new species. Today, we know its striped patterning is actually the result of a genetic mutation. Only a handful of these cats have ever been seen in the wild. Photo: StuPorts, iStock

On this day in 1969, Apollo 11's Neil Armstrong became the first person to walk on the Moon! The journey was an astounding achievement: Scientific results & specimens gathered by Armstrong & Buzz Aldrin on the surface fueled research long after the mission's end. Photo: NASA, PD, Wikimedia Commons

Did you know? The Museum's Apatosaurus was originally displayed with the wrong skull. Because this dino's remains were incomplete, a speculative skull (based on a different sauropod—Camarasaurus) was sculpted. As new research emerged, it was updated.

Happy #WorldSnakeDay! 🐍 We’re heading into the Museum’s Department of Herpetology to learn some interesting facts about these diverse and important reptiles.

My sketch of @amnh.org, drawn from a bench on Central Park West #urbsnsketchers

🗣️Don't miss these events at the Museum today! 🗽From Stoops to Stadiums: How New Yorkers Play, 3–10 pm ➡️In celebration of FIFA World Cup 2026, the Museum invites you to a block party and Manhattanhenge viewing event! This free event draws inspiration from the sports and games of the five boroughs.

Block Party + Manhattanhenge Viewing - July 11 | AMNH

Celebrate global play and local culture at an outdoor block party that culminates in a Manhattanhenge viewing.

amnh.link

(1/8) For #FossilFriday – What can ~555-million-year-old fossils tell us about the earliest animal behaviors? Excited to share a new article with Blakely Webb, @chemosymbiosis.bsky.social, Bill Parker & @marydroser.bsky.social in Scientific Reports investigating evidence of motility in Spriggina

Come one come all! www.amnh.org/calendar/mot...

Moths in New York City: Museum Celebration - Jul 23 | AMNH

Discover New York City's insects at an evening all about the science and wonder of moths.

amnh.org

For #FossilFriday, meet the oldest known "righty" in the animal kingdom & the earliest animal with a head: Spriggina floundersi. It measured just a few centimeters long & favored its right side, according to research led by @amnh.org's assistant curator of invertebrate paleontology Scott Evans 🧪

Mindy Weisberger@laminda.bsky.social · 4w ago

Whether you're a righty or a lefty, favoring one side over the other is a trait in animals that's incredibly old. In fact, scientists just identified the earliest evidence of this preference, in an ancient wormlike weirdo that lived about 550 million years ago and tended to bend to the right 🧪

Are you right- or left-handed? You may have something in common with this 550-million-year-old animal! 🤯 👉 Meet Spriggina—the world’s first “right-handed” animal! Long before dinosaurs, this little organism crawled along a slime-covered seafloor and preferred bending to the right.

Meet the Pacific stargazer, an ambush hunter spends most of its life buried beneath the sand. Its upturned face allows it to see even when most of its body is concealed. And? It's capable of stunning prey with electrical shocks of ~50 volts! Photo: alboertoalcala, CC BY 4.0 iNaturalist

🌇The Museum’s Manhattanhenge program returns this Saturday, 7/11, with a lecture & viewing event celebrating the last opportunity to see the Manhattanhenge effect in 2026. Join Associate Curator Jackie Faherty for an exploration of the rare alignment of the setting Sun with Manhattan’s street grid.

Manhattanhenge: Museum Lecture + Live Viewing July 11 | AMNH

Attend a presentation on the science of Manhattanhenge, followed by an outdoor block party and viewing of the phenomenon.

amnh.link

Have you ever seen one of these at the beach? Also known as “sand crabs” or “sand fleas,” Pacific mole crabs migrate with the tides, feeding on plankton brought in by the waves. These critters use their back legs to get around, and they burrow backwards, too. Photo: eeowes, CC BY-NC 4.0, flickr

Ever seen the polka dot wasp moth? This insect inhabits neotropical regions in parts of South America, Central America, & North America. It can grow ~2 in (5.2 cm) long. While these insects don’t sting like true wasps, they are toxic to predators. Photo: Andrea Diaz,CC BY-NC 4.0, iNaturalist

Does the summer heat make you feel like the bald-headed uakari (Cacajao calvus)? Scientists think that the bright color of this Amazonian primate’s face may actually be an indicator of health—and that individuals with lighter faces are less desirable as mates. Photo: DC_Colombia, iStock

Did you know? There are 6000+ known species of these tiny arachnids. True to their name, jumping spiders don’t use webs to snare food. Instead they pounce on their prey. They're easily recognizable thanks to large forward-facing eyes. Photo: jeepgirlco, CC BY-NC 4.0, iNaturalist