June 7th

What is–and is not–a dinosaur?

Want to avoid the ire and swift corrections of a fervent dinophile? One of the first and most common ways to get a conversation off on the wrong foot is to confuse dinosaurs with other prehistoric creatures. It may not seem terribly important to most people, but getting the nomenclature right is one of the easiest ways to show you have an understanding of the prehistoric world. Need some help distinguishing dinosaurs from non-dinosaurs? We’re here to help.

No matter how many blog posts and soapbox-style rants appear on this issue, the general public has–for the most part–never been taught to distinguish a dinosaur from any other extinct animal. We’re not here to point fingers. We just want to clear up some mis-conceptions.

Firstly, dinosaurs are a very special group of animals that arose in the Triassic period, and, with the exception of modern birds, went extinct at the end of the Cretaceous period–some 160 million years. Dinosaurs are separated from other kinds of animals by several distinct anatomical criteria–adaptations, chiefly, of the limbs and the feet. Dinosaurs walked with their legs directly under their bodies, unlike reptiles which trudge through life with a sprawling posture.

Because dinosaurs are defined scientifically by their characteristic limbs, we cannot call a pterosaur a “flying dinosaur.” It is an altogether different sort of creature. Nor can we confuse sea dragons like ichthyosaurs, plesiosaurs, or mosasaurs as dinosaurs. The limbs of these animals have all been modified and are not direct descendants of dinosaurs. They are evolutionary cousins.

Mammoths and other prehistoric mammals are also not dinosaurs. Neither are pelycosaurs like the sail-backed Dimetrodon.

When in doubt, look for museum labels and online assistance to determine what you’re seeing. Understand the repercussions of how an animal is classified and what those distinctions mean.

Need help deciding whether an animal is a dinosaur or not? Ask us on Facebook and Twitter using the hashtag #TDIDinos.

June 6th

1947 – Zallinger completes his Age of Reptiles

On this day in dinosaurs, Rudy Zallinger completed what is perhaps the most infamous painting in paleontology–the Age of Reptiles at the Yale Peabody Museum of Natural History. The painting, done in the Renaissance fresco secco style–similar to the process Michelangelo used for his Sistine Chapel masterpiece–and took 4 and a half years to complete.

Zallinger’s work earned him a Pulitzer Award for painting in 1949. He was later asked to paint another mural for the Yale Peabody museum: The Age of Mammals. Both murals are still on public view at the museum.

Share your favorite memories of Zallinger’s masterwork with us on Facebook and Twitter using the hashtag #TDIDinos.

June 5th

1888 – Hatcher discovers Ceratops

On this day in dinosaurs John Bell Hatcher discovered remains of an animal he named Ceratops, “horned face.” Hatcher unearthed an occipital condyle–the doorknob-like structure at the back of the skull that attaches to the vertebrae–and two horn cores from the beast.

While Ceratops is considered a “nomen dubium” today, meaning the name is no longer used because the remains of the animal are too fragmentary and indistinguishable from other similar species, the moniker is still important in the history of dinosaur paleontology. This creature gave its name to the ceratopsian family that we know commonly as the horned dinosaurs.

2009 – Land of the Lost movie debuts

Also on this day in dinosaurs, a film version of a beloved Saturday morning classic television show premiered. Unlike its wildly popular predecessor (and a 90’s TV remake), this film did not produce box office gold or a lasting legacy. Even with CGI dinosaurs, Land of the Lost got lost in the summer shuffle alongside some blockbusters like The Hangover and Harry Potter and the Half-Blood Prince.

Despite its shortcomings in earnings, the film possesses a cult following–as many dinosaur movies do.

Share your favorite ceratopsian photos and memories of Land of the Lost with us on Facebook and Twitter using the hashtag #TDIDinos.

June 4th

2015 – Regaliceratops announced

On this day in dinosaurs, a new ceratopsian was described for the first time. With pentagon-shaped spikes along the back of its neck frill, paleontologists thought the dinosaur seemed crowned. They named it Regaliceratops, “royal horned face.”


Like its cousin, Triceratops, Regaliceratops has 3 horns. Two over the eyes and one on its nose. But Regaliceratops bears small horns over its eyes and a larger nose horn.

The crown effect gave the dinosaur the nickname “Hellboy” which reverberated around the internet and gave this chasmosaurine its 15 minutes of fame.

Share your favorite photos of horned dinosaurs with us on Facebook and Twitter using the hashtag #TDIDinos.

June 2nd

2012 – Houston Museum of Natural Science unveils new Hall of Paleontology

On this day in dinosaurs, the Houston Museum of Natural Science opened its new dinosaur hall opened to much fanfare. At a price tag of  $85 million, the Morian Hall of Paleontology aims to take visitors on a prehistoric safari. The museum sought the expertise of world-renowned paleontologist Robert Bakker to create the experience of a journey through geologic time.

Houston Chronicle

The 30,000 square foot hall features theatrically posed fossil specimens, many attacking prey or evading predators themselves. As one of the most comprehensive and dynamic prehistoric displays in the U.S., the Houston Museum’s collection of dinosaurs has become a favorite among dinophiles of all ages.

Share your pictures from the Morian Hall of Paleontology at the Houston Museum of Natural Science with us on Facebook and Twitter using the hashtag #TDIDinos.

June 1st

1983 – Police release Synchronicity

On this day in dinosaurs, “Mr. Brontosaurus” got a big name drop from Sting and the Police in the song “Walking in your Footsteps” on the Synchronicity album. The song explores the relationship between the dominion of the dinosaurs and their subsequent extinction with humanity’s flirtations with atomic destruction.

Brontosaurus at the Yale-Peabody Museum / Extinct Monsters

The song’s message is poignant several decades later, but we’d be remiss if we didn’t point out that 50 million years ago is not nearly an early enough time to spot a dinosaur. To really talk to Mr. Brontosaurus, Sting and Co. would need to travel back 150 million years.

Are you walking in dinosaur footsteps? Share your photos of dinosaur trackways, Brontosaurus, and, of course, your favorite memories of the dinosaur-inspired music with us on Facebook and Twitter using the hashtag #TDIDinos.

May 31st

2001 – Paralititan announced in Philadelphia

On this day in dinosaurs, an African behemoth was unveiled for the first time. A team of researchers announced the discovery of sauropod skeletal remains, including a 5 and a 1/2 foot humerus, belonging to an animal that may have weighed as much as 60 tons.

Paralititan / Wikimedia Commons

Paralititan means “tidal giant” and the animal’s species name, stromeri, honors Ernest Stromer, the German baron who lost his African dinosaur fossils to allied bombs during World War II. “Stromer’s tidal giant” lived 94 million years ago in what is now the Sahara. Back then, North Africa was a large river system teeming with gigantic predators who all needed prey. A “60 ton steak” would have done nicely.

Paleontologists estimate that Paralititan was between 80 and 100 feet long, making it one of the largest animals ever to walk the earth. Its remains were scavenged by predators, but enough of the beast survived to make its identification as a sauropod clear. It may have been related to South American titanosaurs, like Argentinosaurus.

The team of researchers who discovered the bones in the Sahara presented their find to the public at the Academy of Natural Sciences in Philadelphia.

Share your images and memories of the Paralititan discovery with us on Facebook and Twitter using the hashtag #TDIDinos.

May 30th

The Changing Fortunes of Extinction

Everyone knows that non-avian dinosaurs are extinct. This catastrophe for the dinosaurs led, over many millennia, to the mammalian dominance that has persisted for the past 66 million years. While many people are aware that mammals took their shot when the opportunity was given to them, it is uncommon knowledge that dinosaurs were given the same chance almost 150 million years earlier.


The earliest dinosaurs appeared during the Triassic period, alongside a wide range of other animals–crocodilians, proto-mammals, large amphibians, and other enormous creatures. The first dinosaurs were small, fleet-footed runners. They diversified in the late Triassic, and then nature gave them a platform.

An extinction event at the end of the Triassic, 201 million years ago, created a vacuum in the terrestrial ecosystems that dinosaurs seized. It was this mass dying that led to the giant Jurassic dinosaurs that would follow. With less competition, the dinosaurs spread across the globe and assumed a bewildering variety of forms. It was extinction that allowed dinosaur dominance.

No clear-cut reason for this extinction event has been identified, but the usual culprits–asteroid impact, sudden climate change, violent volcanic eruptions–have all been debated.

The Cretaceous extinction event eliminated the last of the non-avian dinosaurs, but surely the most successful group of terrestrial vertebrates in the planet’s history would have understood the value of taking an opportunity when it arises. There is never any guarantee that extinction will stay its hand.

Share your thoughts on extinction with us on Facebook and Twitter using the hashtag #TDIDinos.

May 29th

What Nests Tell Us

A nest is an intimate thing. It’s not a home, but a place only for birth and nurturing. The first publicly heralded discovery of dinosaur eggs took place in Mongolia in 1923. Since then, paleontologists have discovered and described dinosaurs nests all over the world. These relics from the distant past shed light on how life began in the Mesozoic.

Citipati brooding its nest / AMNH

In the 1970s, dinosaur nesting colonies were discovered in Montana–giving scientists clues about the parenting skills of dinosaurs. Eggshells were found crushed in the nest, and the associated remains of youngsters showed that their bones hadn’t developed enough for walking. This means that the adults were bringing food back to the nest until the young were large enough to walk out on their own. Other species exhibited largely intact eggshells, meaning that the baby dinosaurs were up and out of the nest quickly and foraging alongside their parents.

We also find that dinosaur colonies resemble bird nest sites, in that the spacing between the nests is equal to the length of an adult. So the dinosaurs were closely packed together, as avian colonies are today. Unlike birds, the big dinosaurs were too heavy to sit on their eggs. They’d crush the little things, rather than incubate them. Dinosaurs relied on rotting vegetation to provide the necessary heat. Smaller dinosaurs, like Citipati (pictured above) were able to incubate their eggs in a more typically avian fashion.

Dinosaurs are often regarded as large animals, but their eggs don’t get very big. The eggshell needed to be thin enough for the baby’s respiration to occur, while also being thick enough to hold the egg together. This means that even the largest dinosaurs began life in small eggs, and by studying the bones of youngsters, we can see how fast they grew–and in many cases, their growth rates were astronomical, reaching adult size in just a few years.

In less than a century, we’ve learned so much from dinosaur nest sites. Share your favorite dinosaur egg photos and memories with us on Facebook and Twitter using the hashtag #TDIDinos.