An artist’s recreation shows (top to bottom) the skeleton, muscles, and living appearance of Deinosuchus.
Credit: © Tyler Stone

Paleontologists (scientists who study prehistoric life) learned more about a terrible crocodile this summer. A study by Adam Cossette of the New York Institute of Technology and Chris Brochu of the University of Iowa examined newly discovered fossil remains of the extinct crocodilian Deinosuchus. Crocodilians are group of reptiles that includes crocodiles, alligators, gavials, and caimans. The scientists published a revised description of the animal in the Journal of Vertebrate Paleontology.

Deinosuchus lived from about 82 million to 75 million years ago, during the late Cretaceous Period. Its closest living relatives are alligators. In most ways, it looked much like a modern alligator, except that it was enormous. Deinosuchus grew to a length of 33 feet (10 meters) or more and weighed about 8,000 pounds (3,600 kilograms). In comparison, the largest crocodilian alive today, the saltwater crocodile, reaches lengths of about 23 feet (7 meters) and weighs 2,200 pounds (1,000 kilograms).

Deinosuchus also lived like modern crocodilians. During the late Cretaceous, much of central North America was covered by a shallow sea. Deinosuchus lived in the vast wetlands on the edges of this sea. Like large crocodilians today, Deinosuchus was an ambush predator. It would swim over to an animal at the water’s edge, lunge out of the water to grab it with its powerful jaws, drag its prey into the water, and drown it. What was on the menu? Just about anything—including dinosaurs.

Numerous fossils of contemporary dinosaurs show bite marks from an animal that could only have been Deinosuchus. It even attacked large, meat-eating theropods (dinosaurs like Tyrannosaurus Rex) on occasion. But for the most part, these predators stayed out of each other’s way, much as lions and Nile crocodiles do in modern Africa.

Deinosuchus was not identical to modern crocodilians, however. it had a greatly thickened skull relative to its size. The thickness likely strengthened it for struggle against dinosaurs and other large prey. Deinosuchus also had a bulbous (rounded) snout, with two small openings at its tip. Paleontologists do not yet know what purpose these features served.

Deinosuchus wasn’t the only giant crocodilian. Sarcosuchus, which lived about 110 million years ago, may have reached 40 feet (12 meters) long, about the length of a bus. Another titan was Purussasaurus, which attained similar proportions during the Miocene Epoch, long after the dinosaurs went extinct.

Discovering a new kind of prehistoric animal is great, but learning more about one that has already been discovered is great, too! Deinosuchus is not a recent discovery. In fact, it was first described in 1909. But many of the fossils were incomplete. With the new material, Cossette and Brochu were able to uncover more about the animal’s lifestyle and better differentiate between the small handful of Deinosuchus species. In doing so, they paint a more complete picture of what the world was like tens of millions of years ago—and what a terrifying place it was!

In Peru, a unique conservation effort is taking place near the city of Cusco at the Parque de la Papa (Park of the Potato). Located outside the Andes Mountains town of Pisac (or Pisaq), the park celebrates the Peruvian potato, of which there are some 3,000 varieties. The park is also a living tribute to the cultural heritage of the region’s indigenous (native) communities.

Potatoes originated in the highlands of Peru and nearby areas of the Andes Mountains. Credit: © Shutterstock

The Parque de la Papa is administered and farmed by the local Amaru, Chawaytire, Pampallacta, Paru Paru, and Sacaca indigenous communities. Within its grand boundaries—the park covers over 22,000 acres (9,000 hectares)—are grown more than 1,300 varieties of potato native to that area of the Andean highlands. Many potato varieties in the park are found nowhere else in the world. The cultivation of such rare potatoes helps ensure their existence for future generations, as does the park’s sharing of precious seeds with the Svalbard Global Seed Vault, a long-term seed storage facility in Norway.

The Parque de la Papa demonstrates the ability of potatoes to survive in the region’s harsh but changing conditions. The park sits in the cold and thin air at an altitude of 12,000 feet (3,700 meters) above sea level. Climate change is bringing warmer temperatures, however, forcing farmers still higher to reach the optimum growing environment for some potato varieties.

Peru is home to some 3,000 varieties of potato. Credit: © Shutterstock

Visitors to the park learn about traditional potato cultivation, harvesting, cooking, and storage. They are also treated to delicious local potato dishes. Hiking trails allow people to walk off their meals while also providing panoramic views of the Andean highlands. The Parque de la Papa features a variety of local crafts and products—from cosmetics and teas to medicines and textiles—made from potatoes and other plants native to the area.

A patchwork of potato fields covers this section of the Altiplano, a cold plateau in the Andean highlands. Credit: © Roux Frederic, Shutterstock

The potato originated in the Andes Mountains of South America. Scientists believe cultivated potatoes came from a species that first grew around Lake Titicaca, in what are now Bolivia and Peru. People living there and in surrounding areas were growing potatoes long before Spanish explorers arrived in the early 1500′s. Potatoes were then introduced to Europe and other parts of the world. The nutritious potato became a vital food crop in many regions.

March 30, 2020

Some 15 million years ago, long after the non-bird dinosaurs and the beasts they lived alongside had gone extinct, giant creatures still walked (or swam) the Earth. Recently, the discoveries of a team of scientists led by Edwin Cadena of Del Rosario University in Colombia have been putting more of a face—or a shell, in this case—on one of these ancient giants. And, not only did the giant have a shell, but the shell had spikes! Meet Stupendemys, the titanic turtle.

Stupendemys lived during the Miocene Epoch, around 23 million to 5.3 million years ago. credit: © Jaime Chirinos

The giant aquatic (water-dwelling) Stupendemys had a big head with a sharp beak. It had four paddlelike limbs and a short tail. It probably could not withdraw its head or limbs into its large shell, as can many turtles. Its shell alone measured about 8 feet (2.4 meters) long. Stupendemys weighed about 2,500 pounds (1,150 kilograms). It and the prehistoric marine turtle Archelon were the largest turtles known to have ever lived.

Stupendemys had been known since the 1970’s from huge pieces of shells and limb bones, but no cranial (skull) material had been positively identified. Cadena’s new trove of Stupendemys fossils included skull fragments, however. Found in Colombia and neighboring Venezuela, the skull pieces matched those of previously unidentified ancient turtle remains discovered in other parts of South America, showing that Stupendemys was fairly widespread.

Some­ of the Stupendemys shells found by Cadena and his team had large forward-pointing horns at the shoulders. The scientists believe this is a case of sexual dimorphism. Sexual dimorphism is a difference in body size or shape between males and females of the same species. Males probably used these horns in combat over mates and territory. Deep gouges were often found near the Stupendemys shell horns, suggesting that males literally locked horns when fighting.

Stupendemys was not the top boss of South American waterways during the Miocene Epoch, a time in Earth’s history that lasted from 23 million to 5.3 million years ago. The turtle was likely a gentle giant, surviving on a diet of hard-shelled mollusks, fruits, and seeds. And its huge size did not grant it complete protection from predators. Giant crocodilians prowled the region at that time, including the 40-foot (12.5-meter) giant caiman Purussaurus. One Stupendemys shell found by Cadena’s team contained an embedded crocodilian tooth! It’s hard to say who came out on top in that encounter, but it was likely an epic struggle.

October 18, 2019

Recent excavations in central Thailand have led to the discovery of a new type of predatory dinosaur, Siamraptor suwati. The ancient creature belonged to a group of giant meat-eaters called carcharodontosaurs, which means shark-toothed reptiles. Siamraptor dates from the Cretaceous Period, a time in Earth’s history from about 145 million years ago to 66 million years ago. The Cretaceous was the last of the three periods that make up the Mesozoic Era, the time when the dinosaurs lived.

Fossils found in Thailand helped scientists reconstruct the skull of the newly identified Siamraptor suwati dinosaur. Credit: Duangsuda Chokchaloemwong, et al/Nakhon Ratchasima Rajabhat University

Siamraptor (Siam is the previous name for Thailand; raptors were carnivorous, bipedal dinosaurs) is the first example of a carcharodontosaur to be found in Southeast Asia. Previous examples came from northern Africa and Europe, and close cousins have been found in Argentina (Giganotosaurus) and the United States (Acrocanthosaurus).

The fossilized bones of Siamraptor were found in 115-million-year-old rocks in the central Thai district of Ban Saphan between 2008 and 2013. Paleontologists from Thailand’s Nakhon Ratchasima Rajabhat University found the fossils—22 in all—while working on a project with Japan’s Fukui Prefectural Dinosaur Museum. The announcement that the fossils belonged to a new type of carcharodontosaur came in October 2019 after years of study. Siamraptor was not the first find for the Japan-Thailand Dinosaur Project. The team earlier identified two new types of plant-eating dinosaurs and an ancient relative of the alligator and crocodile.

Twenty-two fossils aided in the skeletal reconstruction of Siamraptor suwati. Credit: Duangsuda Chokchaloemwong, et al/Nakhon Ratchasima Rajabhat University

The Siamraptor fossils include parts of a single animal’s feet, hands, hips, spine, and skull. The animals’s bones were somewhat porous, containing air sacs that would have made the creature a lighter and more agile hunter. Nearby were also many Siamraptor teeth, suggesting that this animal had not been alone. Like sharks, dinosaurs shed teeth throughout their lives, particularly when they ate, and the Ban Saphan site (a floodplain during the Cretaceous Period) may have been a common feeding ground. Siamraptor probably preyed on plant-eating dinosaurs in the area, using its bladelike serrated teeth—measuring up to 6 inches (15 centimeters) long—to slice through tough dinosaur flesh.

Scientists classify Carcharodontosaurus with other meat-eating dinosaurs in a large group known as theropods. These animals make up one of two main groups of saurischian (lizard-hipped) dinosaurs. Saurischians include such famous dinosaurs as Tyrannosaurus and Velociraptor. Although Carcharodontosaurus is classified in the same main group as Tyrannosaurus and Velociraptor, it was not closely related to them.

Tyrannosaurus and Carcharodontosaurus shared such traits as big heads, long bodies, and short arms, but the animals’ snouts were quite different. Tyrannosaurus had a broad head and a wide mouth with teeth made for crushing bone and pulling away flesh. Carcharodontosaurus had a much narrower head and a more precise bite with sharper teeth meant for slicing flesh. The two apex predators (at the top of the food chain) appear to have coexisted in several areas, which probably made for some rather interesting confrontations.

September 30, 2019

Last month, in late August, scientists published a description of a 3.8-million-year-old fossil skull, allowing people to gaze into the face of perhaps our earliest ancestor, Australopithecus anamensis. According to one researcher, the remarkable fossil is the most complete skull of the “oldest-known species” of the human evolutionary tree. The important fossil helps define the ancient human evolutionary family, but it also brings more questions to the often cloudy relationships among that family’s members.

Paleontologists discovered the near-complete skull of Australopithecus anamensis in Ethiopia in 2016. Credit: © Dale Omori, Cleveland Museum of Natural History

A. anamensis belongs to the hominin group of living things that includes human beings and early humanlike ancestors. A team of paleontologists led by Yohannes Haile-Selassie from the Cleveland Museum of Natural History found the hominin skull in 2016 at a site called Woranso-Mille in the Afar region of Ethiopia. The fossil, officially known as MRD-VP-1/1 (MRD for short), was discovered in two halves that fit together, making up a nearly complete skull. The skull’s position in volcanic sediments enabled scientists to determine its age—3.8 million years—with great precision. The anatomical features of the skull helped identify it as A. anamensis, one of the earliest known hominin species. This species was first identified from a handful of fossil skull fragments and other bones discovered at Lake Turkana in northern Kenya in the 1990’s. Those specimens are between 4.2 million and 3.9 million years old.

Scientists used the fossilized Australopithecus anamensis skull to create this image of one of humankind’s earliest ancestors. Credit: © John Gurche/Matt Crow, Cleveland Museum of Natural History

The MRD skull shows that A. anamensis had a small brain, a bit smaller than that of a modern chimpanzee. The skull more closely resembles an ape than a modern human, with a large jaw and prominent cheekbones, but the canine teeth are much smaller and more humanlike. And, like humans, A. anamensis walked upright on two legs. Sediments and other fossils show that the region where the skull was found was arid, but the ancient creature died in a vegetated area near a small stream that entered a lake.

The site in Ethiopia where MRD was discovered is not far from the village of Hadar, where fossils of another early hominin, Australopithecus afarensis, were first discovered in 1974. A. afarensis is known mainly from the partial skeleton of an adult female, the famous “Lucy,” found in deposits dating to about 3.2 million years ago. Other A. afarensis fossils date to nearly 3.8 million years ago, which suggests Lucy and her kind may have coexisted with A. anamensis.

Most scientists, however, think that Lucy and her kind evolved from A. anamensis, and that the transition occurred as one species disappeared and the other took over. Scientists now understand that A. anamensis could still be ancestral to Lucy, but that other A. anamensis populations continued to thrive unchanged as her neighbors. The prehistoric landscape of East Africa had many hills, steep valleys, volcanoes, lava flows, and rifts that could easily have isolated populations over many generations. Over time, the populations eventually diverged. Scientists think that one of these species eventually gave rise to Homo, the human genus.

August 26, 2019

In New Zealand, a newly identified species of ancient giant penguin—or “monster” penguin as dubbed by the Canterbury Museum in Christchurch—has added to the southwest Pacific island nation’s roster of extinct oversized animals. The leg and foot bones of Crossvallia waiparensis, a 5-foot, 3-inch (1.6-meter) tall, 180-pound (80-kilogram) penguin, were found in Waipara, North Canterbury, on New Zealand’s South Island.

This illustration shows the ancient giant penguin Crossvallia waiparensis alongside a modern human. Credit: © Canterbury Museum

The ancient “monster” penguin bones were discovered in 2018 at Waipara Greensand, a geological formation that has produced significant penguin fossils before. Researchers from the nearby Canterbury Museum and the Senckenberg Natural History Museum in Frankfurt, Germany, studied the penguin fossils, and they named C. waiparensis as a new species in the Aug. 12, 2019, issue of Alcheringa: An Australasian Journal of Palaeontology.

C. waiparensis, which lived during the Paleocene Epoch between 66 million and 56 million years ago, was roughly four times larger than the emperor penguin, the largest of all modern penguins. During the time of C. waiparensis, New Zealand was still attached to Australia, which was once connected to Antarctica. A related prehistoric giant penguin, Crossvallia unienwillia, was discovered in Antarctica’s Cross Valley in 2000. The leg bones of both giant penguins suggest their feet were more adapted for swimming than those of modern penguins, and they may not have stood upright as modern penguins do.

Emperor penguins, seen here in Antarctica, are the largest living penguins. They stand about 3 feet (1 meter) tall and weigh as much as 100 pounds (45 kilograms). (Credit: © Shutterstock)

Prior to the discovery of C. waiparensis, New Zealand’s legacy of ancient giant critters already included the world’s largest parrot (Heracles inexpectatus), a massive eagle (Hieraaetus moorei), a dog-sized burrowing bat (Vulcanops jennyworthyae), the more than 6-foot (2-meter) tall moa, and other giant penguins.

July 8, 2019

Since prehistoric times, people have depicted animals in their artwork. Ancient paintings and drawings of horses, oxen, and other animals appear on the ceilings, walls, and entrances of caves and rock shelters around the world. In more modern times, animals have continued to be a source of artistic inspiration. Many cultures have shown animals in artistic representations of rural life, as livestock, prey, or pets, or to illustrate legends and myths. Many cultures, too, include animals in art simply for their beauty or for their intimate connections with humans. At the National Gallery of Art in Washington, D.C., a new exhibition is detailing “The Life of Animals in Japanese Art.”

These wooden sacred foxes are part of the “Life of Animals in Japanese Art” exhibition at the National Gallery of Art in Washington, D.C. Credit: Sacred Foxes (Nanbokuch periods, 14th century), wood with pigments by unknown artist; National Gallery of Art

The Life of Animals in Japanese Art is the first exhibition devoted solely to animals at the National Gallery of Art. The exhibition shows animals—some real, some imaginary, some sacred, some merely beloved—in a wide variety of artistic mediums. The more than 300 works in block prints, ceramics, decorative arts, lacquerware, paintings, sculptures, and textiles span from the A.D. 400′s to the present day. The artworks—including seven designated as “Important Cultural Property” by the Japanese government—come from public and private collections in both Japan and the United States. The exhibition began on June 2, 2019, and runs through August 18.

These 1,000-year-old sacred monkeys are included in the “Life of Animals in Japanese Art” exhibition. Credit: Pair of Sacred Monkeys (Heian period, 11th century), wood with traces of pigment by unknown artist; Los Angeles County Museum of Art/National Gallery of Art

The sprawling exhibit occupies 18,000 square feet (1,700 square meters) of the National Gallery of Art’s East Building Concourse, and it is divided into various themed sections. The credited artists (many older works are unattributed) include the Zen Buddhist monk Sesson Shūkei (1504-1589), the painter Itō Jakuchū (1716-1800), and the painter and woodblock printer Katsushika Hokusai (1760-1849). Such modern artists as Kusama Yayoi (1929-…), the clothing designer Issey Miyake (1938-…), and the painter and sculptor Murakami Takashi (1960-…) are also represented.

The Life of Animals in Japanese Art is part of a series of events included in Japan 2019, an initiative to promote Japanese culture in the United States. Earlier Japanese art exhibitions took place at the Metropolitan Museum of Art in New York City and the Cleveland Museum of Art. The animal art exhibition will move to the Los Angeles County Museum of Art in September, and a number of Japan-themed concerts, festivals, and performances are taking place in the United States throughout 2019.

December 7, 2018

On Dec. 9, 1962, 56 years ago Sunday, the United States Congress established Petrified Forest National Park, an area with one of the greatest and most colorful concentrations of petrified wood in the world. Located in the Painted Desert in northeastern Arizona, the park contains giant logs of agatized wood (wood petrified into agate) and numerous broken sections and petrified fragments. Visitors can view petrified wood and other park features while hiking the park’s many trails. The park also contains dinosaur fossils and Native American petroglyphs (rock carvings).

These petrified logs at Petrified Forest National Park are about 225 million years old. Credit: © George Burba, Dreamstime

The trees of Petrified Forest National Park grew about 225 million years ago during the Triassic Period, when reptiles became the dominant animals on land and in the sea. Reptiles of the Triassic Period included the first dinosaurs and early large marine reptiles. The trees were buried in mud, sand, or volcanic ash, and turned to stone over time. Today, the park is home to a wide variety of plant and animal life. Cactuses, grasses, lichens, and wildflowers live there, as do many types of birds, lizards, rabbits, and other animals.

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Petrified Forest National Park is located in the Painted Desert in northeastern Arizona. Credit: WORLD BOOK map

People of the Clovis culture first inhabited the area of the park around 13,000 years ago. Fragments of pottery found in the forest show that small groups of farming Indians lived there as early as A.D. 300. Spanish explorers reached the area in the late 1500′s, and American pioneers and homesteaders began settling there in the 1800′s.

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This map shows the locations of the national parks of the United States, which form part of the country’s National Park System. Credit: WORLD BOOK map

U.S. President Theodore Roosevelt created Petrified Forest National Monument in 1906. After becoming a national park in 1962, the Petrified Forest National Wilderness Area was added within the park in 1970. In 2004, the park expanded from 93,533 acres (37,851 hectares) to 218,533 acres (88,437 hectares). Later additions brought the park’s area to 221,390 acres (89,593 hectares).

July 7, 2017

A new study of ancient cat DNA reveals what many cat owners might long have suspected: your pet is barely domesticated at all. A team of scientists analyzed genetic material from more than 200 ancient cats obtained from Viking graves, Egyptian mummies, and Neolithic (later Stone Age) sites. The study revealed that despite having lived alongside people for thousands of years, cats really began to change only quite recently. The study was published in June in the journal Nature Ecology and Evolution.

A recent study showed that domestic cats like this Maine coon remain genetically quite similar to their wild ancestors. Maine coons, developed in New England in the 1800′s, are the largest domestic cat breed. Credit: © Linn Currie, Shutterstock

Cats have a long association with people. Archaeologists discovered a cat buried alongside a human in a 9,500-year-old grave in Cyprus. Yet cats have not not been fully domesticated the same way that dogs, cattle, pigs, sheep, or goats have been. Those familiar pet and farm animals differ from their wild ancestors in anatomy, behavior, and genetics. Modern house cats, however, remain very similar to their wild ancestors. Pet cats, of course, are much smaller than their wild cousins, but they remain near anatomic mirrors. Behaviorally, watch a panther or a lion in a nature program or in a zoo—then a house cat stalking a bird or simply watching you walk across the room—and you might notice quite similar patterns: sleeping a lot, playing, grooming, investigating, hunting, and even jumping into empty boxes. And genetically speaking, despite thousands of years of human interaction, pet cats did not begin to change until the past few centuries—and then, only a little. The domestication of cats has been neither complete nor easy. In fact, all house cats are descended from just one presumably friendlier-than-the-rest ancestor: the African wildcat.

The wildcat, from which modern house cats descended, still roams Africa, Asia, and Europe. Look familiar? Credit: © Vova Pomortzeff, Shutterstock

The genetic study focused on cat mitochondrial DNA (mtDNA), which is inherited unchanged solely from the mother. This fact makes mtDNA especially useful to trace the ancestry of different animal species. The genetic evidence showed that cat domestication probably began about 9,000 years ago in the Middle East, where farming started. Scholars think that wild cats (wildcats among them) were initially attracted to rodents that infested grain stores of early farmers. With plenty to eat, the cats stuck around the farms but never became fully domesticated. Cats then followed farming peoples as they migrated into Europe more than 6,000 years ago.

The genetic study showed that the familiar tabby markings of modern cats developed during the Middle Ages. Credit: © Shutterstock

The recent study found, however, that most modern pet cats are not directly descended from these first domesticated felines. More than 3,000 years ago, a second episode of cat domestication happened in ancient Egypt. These cats spread out of Egypt to Europe and beyond along Greek and Roman trade routes as far north as Scandinavia and into Asia. Most modern pet cats are descended from this second migration group.

The mtDNA analysis revealed that most domestic cats over the past 9,000 years were striped, like their wild ancestors (witness the tiger). The familiar tabby coats—symmetrically patterned with light stripes and blotches of a dark and light colors—of many house cats today were uncommon until the Middle Ages. It was around that time that people started paying more attention to their cats and started breeding them for different appearances and purposes. The genetic evidence even pinpointed the tabby mutation to western Turkey in the 1300’s. Most cats today carry this tabby gene, but there are now many different breeds from all over the world. The vast majority of cat breeds have been created since the early 1900’s.

Cat shows are popular today, but the very first cat show was much earlier than you might think. According to most accounts, the first show took place in 1598 at St. Giles Fair in Winchester, England. The first modern cat show was held at London’s Crystal Palace in 1871.

April 28, 2017

For decades, dinosaurs have been grouped into two broad categories: long-necked sauropods and meat-eating theropods (along with birds) in one group, and the remaining plant-eaters, such as Stegosaurus, Triceratops, and Iguanodon, in the other. In March, a group led by Matthew G. Baron from the University of Cambridge in the United Kingdom challenged that view. They published their findings in the prestigious scientific journal Nature.

Tyrannosaurus is a fearsome example of a saurischian (reptile-hipped) dinosaur. Credit: © Science Picture Company/SuperStock

To study dinosaur relationships, paleontologists (scientists who study prehistoric life) use a type of analysis called cladistics. In cladistics, researchers evaluate anatomical traits of at least three related species. These evaluations help them construct a cladogram, a kind of family tree illustrating how the species are related to one another. Groups of species that are related to one another are called clades. For dinosaurs, skeletal features are used, such as the absence or presence of a particular bone or a certain feature on a bone.

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The accepted dinosaur family tree describes two major kinds of dinosaurs: ornithischians and saurischians. Credit: WORLD BOOK illustrations by George Fryer, Bernard Thornton Artists

For 130 years, paleontologists have grouped dinosaurs into two large, confusingly named clades based on the arrangement of their pelvic, or hip, bones. All tetrapods (animals with four limbs) possess three paired sets of hip bones: two ilia (singular: ilium), two ischia (singular: ischium), and two pubes (singular: pubis). In one group of dinosaurs, the pubes run from the hip socket down and away from the center of the animal, close to the ischia. Because these hips looked similar to those of birds, early paleontologists named the group Ornithischia, which means bird-hipped. But ornithischians are not closely related to birds.

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This illustration shows the difference between bird-hipped ornithischians and reptile-hipped saurischians. Credit: WORLD BOOK illustrations by Alex Ebel

In sauropods and most theropods, the pubic bones project straight down from the hip socket or at a slight forward angle. This is closer to the condition seen in other reptiles, so they were included in the clade Saurischia, which means reptile-hipped. In some small theropods, however, the pubis is “reversed,” angling away from the center of the body at an angle similar to the ischium. Birds evolved (developed over time) from these theropods, making them members of the “reptile-hipped” clade, even though they truly have bird hips.

Baron studied 73 dinosaur species and catalogued 457 skeletal characteristics with them. He coded these characters into a computer program, which returned new controversial results. Theropods were found to be more closely related to ornithischians, with sauropods and some primitive meat-eaters remaining in Saurischia. Despite their different-shaped hips, theropods and ornithischians were found to be united by more than 20 unique characters. To refer to the clade, Baron and company revived the name Ornithoscelida (meaning bird-legged), which had been coined by the famous British zoologist Thomas Henry Huxley in 1870. Fortunately for the sake of clarity, birds would be considered bird-legged dinosaurs under this system!

The new placement would resolve some puzzles about the origins of dinosaurs. The earliest known dinosaur skeletons are about 230 million years old and have been found in South America. But still older reptiles that are regarded as the ancestors to dinosaurs have only been found in northern regions far from South America. To further muddle things, footprints widely attributed to early dinosaurs have been found in eastern Europe and are some 5 million to 9 million years older than the South American skeletons. With the proposed reorganization, those earliest-known skeletal remains would be considered early relatives of sauropods, suggesting that the earliest dinosaurs have yet to be discovered somewhere in the Northern Hemisphere.

While the proposed rearrangement would solve some problems relating to the origin of some dinosaur features, it would create problems relating to the origin of others. For instance, sauropods and theropods both had air sacs connected to their lungs. These air sacs had long chambers that tunneled through their bones, making them lighter. Based on the new family tree, the first dinosaur would have had to possess these air sacs. Why would ornithischians lose a trait that was apparently so useful to sauropods and theropods and remains vital to birds today? Scientists will continue studying them to try to answer this puzzling question.

Though paleontologists commended Baron for the meticulousness of his work, they were quick to point out that more data would be needed to convincingly rearrange the family tree. The Saurischia-Ornithischia division has been upheld for decades by dozens of cladistics analyses, so it will take more than one new analysis to convince paleontologists to overturn 130 years of study. But the bird-legged dinosaur clade will have a leg to stand on if more fossil discoveries and cladistic analyses back up Baron’s findings.