The Top Ten Dinosaur Discoveries of 2023

From uncovering a tyrannosaur’s last meal to unlocking the secrets of a dino with a really long neck, these were the year’s biggest stories

Dinosaur Skeletons
Ten big dinosaur discoveries stood out in 2023. Full credits with links at bottom of article

Ever since the word “dinosaur” was coined in 1842, paleontologists have been revealing a wealth of primordial detail about the “terrible lizards.” New species are being named at a rapid pace from fossil sites around the planet, and paleontologists are constantly unearthing new clues about what the magnificent reptiles ate, how they socialized, what colors they wore and more. This past year has been full of tantalizing dinosaur discoveries, so we’ve compiled a short list of the most amazing and influential finds of 2023.

1. Mammals bit back at dinosaurs

Dinosaur and Mammal in Tussle
The dinosaur and mammal engaged in a final tussle. Gang Han via the Canadian Museum of Nature

Mammals were not the meek underdogs of the Mesozoic world that they’ve often been characterized as. This past July, paleontologists described the stunning fossil of a cat-sized Cretaceous mammal, Repenomamus, seemingly biting into the ribs of Psittacosaurus, a dog-sized horned dinosaur. Researchers don’t know why the mammal and dinosaur were tussling when they perished, but damaged dinosaur bones indicate that the beast had quite a bite and was not shy about confronting a reptile several times its size.

2. Some dinosaurs laid amazing eggs

Qianlong Eggs
An egg clutch and embryo-bearing egg of Qianlong Full credits with link at bottom of article

Sometimes paleontologists hit the jackpot. The discovery of the dinosaur Qianlong shouhu is one such find. The sauropodomorph dinosaur—a long-necked herbivore that walked on two legs and was distantly related to later giants like Apatosaurus—is known not only from the bones of adult animals, but also from eggs and embryos. Analysis of the eggs, in particular, indicates that they were leathery and hint that the earliest dinosaur eggs would have had similarly flexible shells.

3. A sharp-clawed dinosaur munched plants

The reconstructed skeleton of the dinosaur Troodon, a cousin of carnivorous dinosaurs like Velociraptor. bryan... from Taipei, Taiwan via Wikimedia Commons under CC By-SA 2.0

Troodon has been a bit of a headache for paleontologists. The dinosaur, initially named from a tooth, has required many comparisons and debates over the years to understand what the animal even looked like. We now know that Troodon looked something like a slender Velociraptor, but with large and unusual teeth. Why the dinosaur had such odd choppers was a mystery. Scientists looked at geochemical traces preserved in the dinosaur’s bones, proxies for different food sources, and found that Troodon were hungry for greens as well as small prey. Even though Troodon had sharp teeth and sharp foot claws to pin lizards, mammals and other morsels, it seems this dinosaur often preferred plants and left most of the hunting to sharper-toothed relatives.

4. Dinosaur giants evolved again and again

A reconstruction of Argentinosaurus huinculensis William Irvin Sellers, Lee Margetts, Rodolfo Aníbal Coria, Phillip Lars Manning via Wikimedia Commons under CC By 2.5

We’re often awed by the giant size of many dinosaurs, especially the long-necked, plant-eating sauropods like Patagotitan and Argentinosaurus. But dinosaurs didn’t just get big once and stay that way. An analysis of 250 sauropod species published in May found that truly giant members of this dinosaur group evolved superlative size at least 36 times over the course of a hundred million years. The finding emphasizes that there were probably various evolutionary routes in different habitats for giant size to evolve, and that supersized sauropods perpetually reinvented how to live large.

5. A tyrannosaur ate other dinos for its last meal

Gorgosaurus eating its prey. Artist Julius Csotonyi © Royal Tyrrell Museum of Paleontology

Determining what was actually on a dinosaur’s menu is a tricky task, but sometimes paleontologists get lucky. Paleontologists in Alberta uncovered the well-preserved skeleton of a young Gorgosaurus, or a sleek tyrannosaur that prowled the area around 75 million years ago. Within what would have been the dinosaur’s body cavity were the dismembered remains of two smaller, parrot-like dinosaurs that lived in the same habitat. Not only did this offer some insight into the prey choices of young tyrannosaurs, but the nature of the remains also indicated that the tyrannosaur preferentially ate the hind legs of the carcasses—a choice that made sense given the large amount of muscle dinosaurs had around their thighs and tails. Pass the drumstick.

6. This lawyer destroyed dinosaur replicas

Paleozoic Museum Drawing
A conceptual drawing of the Paleozoic Museum Internet Archive Book Images / Public Domain

It might have been one of the greatest dinosaur museums of all time. A majestic Paleozoic Museum displaying life-size replicas of dinosaurs and other prehistoric creatures was planned for Central Park in the late 19th century, but the beautifully constructed models were destroyed and buried somewhere in the park in 1871. The traditional story is that corrupt politician William “Boss” Tweed was responsible for the dismantling of the dinosaurs, but a June paper identifies a different suspect. Lawyer Henry Hilton is the “real villain,” the study states; he ordered the destruction of the models as the Paleozoic Museum was canceled. The board overseeing Central Park’s projects was concerned about competition with the American Museum of Natural History nearby, as both would rely on impressive prehistoric exhibits to attract visitors. Given Hilton’s reputation for getting rid of items he did not deem useful, the dinosaur sculptures were likely destroyed as a matter of course rather than an act of vandalism.

7. Researchers discovered a new southern dino

A restoration of Gonkoken nanoi Connor Ashbridge via Wikimedia Commons under CC By-SA 4.0

Paleontologists still have much to learn about how dinosaur evolution unfolded in the Southern Hemisphere. Just this June, in fact, experts named a new shovel-beaked dinosaur that survived far longer than expected. Dubbed Gonkoken nanoi, the dinosaur superficially resembles hadrosaurs like the famous Edmontosaurus. Yet Gonkoken was more closely related to the predecessors of the hadrosaurs, having evolved a similar appearance. The ancestors of Gonkoken likely expanded from ancient North America to Cretaceous Chile, evolving in parallel with the hadrosaurs in an area the likes of Edmontosaurus never reached.

8. Dust from the asteroid impact drifted for years

Dust Blowing Over Dinosaur Fossil
After an asteroid hit the Earth 66 million years ago, dust drifted around the planet. Mark Garlick via Getty Images

The Cretaceous ended with the impact of a six-mile-wide asteroid, the effects of which wiped out about 75 percent of life on Earth. Debris from the impact created an infrared pulse that practically roasted the planet on the first day after impact, but the effects of the collision lasted much longer. A study published this October found that silicate dust created by the impact stuck around for as long as 15 years, hindering photosynthesis and contributing to cooling as life was recovering. Even though the cause of the extinction is well known, paleontologists are still uncovering new details of how Earth’s fifth mass extinction played out.

9. This species sported a very long neck

Mamenchisaurus sinocanadorum
A rendering of Mamenchisaurus sinocanadorum, which had a neck that was more than 45 feet long © Júlia d’Oliveira

Mamenchisaurus sinocanadorum had one of the longest necks of all time. Fossils of this herbivorous dinosaur, reassessed by experts this March, indicate that the Jurassic dinosaur had a neck more than 45 feet long—similar to the neck lengths of the largest dinosaurs of all time. More than that, the study found that splint-like bones jutting from the neck vertebrae called cervical ribs helped to provide stability to the dinosaur’s neck and evolved in tandem with increasing air pockets in the dinosaur’s neck bones. The stability afforded by those bony struts in the neck allowed long-necked dinosaurs to evolve lighter and more fragile neck vertebrae, opening the possibility for long-neck record holders like Mamenchisaurus to evolve.

10. Dinosaurs had lips to lick

T. rex
T. rex may have had lips to conceal its teeth Mark Witton

For decades, carnivorous dinosaurs like the iconic Tyrannosaurus rex have been depicted with sharp fangs jutting out from their scaly smiles. But a study published this March proposes that the tyrant lizard and many other dinosaurs had their teeth concealed by fleshy lips not unlike those seen among modern lizards. Drawing from details of dinosaur teeth and jaw bones, the researchers argue that lips would have protected the teeth and helped keep them from drying out due to exposure—while not at all hampering the infamous biting power of T. rex.

Top image: Illustration by Emily Lankiewicz / bryan… from Taipei, Taiwan via Wikimedia Commons under CC By-SA 2.0 / William Irvin Sellers, Lee Margetts, Rodolfo Aníbal Coria, Phillip Lars Manning via Wikimedia Commons under CC By 2.5 / Mark Garlick via Getty Images

Egg clutch image: F. Han, Y. Yu, S. Zhang, R. Zeng, X. Wang, H. Cai, T. Wu, Y. Wen, S. Cai, C. Li, R. Wu, Q. Zhao & X. Xu - Exceptional early Jurassic fossils with leathery eggs shed light on dinosaur reproductive biology via Wikimedia Commons under CC By-SA 4.0

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