Dinosaurs Worth Knowing Beyond Tyrannosaurus rex

This slender Late Triassic hunter had already evolved a long tail and the body plan of a two-legged predator. Numerous skeletons from Ghost Ranch, New Mexico, let scientists check old ideas against more than one fossil. Bones once thought to show an adult eating a youngster were reidentified as those of a small relative of crocodiles.

This Late Triassic plant eater had a small head on a long neck, powerful hind legs, and hands that could grasp. A reconstruction of its joints supported walking on two legs. It shows how different early members of the long-necked dinosaur lineage could look from the four-legged giants that came later.

An Early Jurassic dinosaur from southern Africa, Heterodontosaurus had enlarged, tusklike teeth and a separate row of closely packed cheek teeth. The cheek teeth bear wear from working against each other. That combination shows why the most striking tooth in a fossil jaw doesn't tell you everything about how the animal ate.

Look past the wing feathers and the Late Jurassic fossil still has a long, bony tail. Archaeopteryx also had teeth and claws on the hands. Those features make it especially useful for seeing how birdlike traits appeared alongside traits inherited from earlier theropod dinosaurs.

Spoon-shaped teeth gave this Late Jurassic sauropod a broad surface for crushing coarse vegetation. A youngster found in Utah still had its head attached to the neck when it fossilized. Even tiny bones of the ear and throat survived, giving researchers more to study than the heavy limb bones that often outlast a skull.

At Utah’s Dinosaur National Monument, intact skulls preserve the long, tooth-lined jaws and delicate connecting bones of Allosaurus fragilis. The park also preserves a different Allosaurus species in older rock. That difference matters when putting together the history of large predators in the Morrison Formation.

Feather impressions in an Early Cretaceous fossil from northeastern China extend along the legs as well as the arms. Long flight feathers on all four limbs gave Microraptor gui a very different outline from most living birds. Researchers have used models to test how those extra feathered surfaces could affect gliding.

Three skeletons from Early Cretaceous China preserve traces of long, simple feathers. One belongs to a large adult. That makes Yutyrannus a useful example of an early tyrannosaur relative whose body could carry feathers at a much greater size than the little feathered dinosaurs often found in the same region.

A Psittacosaurus fossil in the Senckenberg collection preserves skin as well as bones. Researchers found evidence of a darker upper body and paler underside, a pattern that can make an animal harder to pick out in uneven light. The specimen is identified to the genus without a definite species name.

The large, curved claw on the second toe catches the eye. John Ostrom also studied the long, stiffened tail and birdlike features of the skeleton. His work on this Early Cretaceous predator helped change how paleontologists understood dinosaur movement and the ancestry of birds.

This armored dinosaur from Early Cretaceous Alberta is preserved with rows of bony plates still in place. A mass inside its body also preserved its last meal. Most of the identifiable plant fragments were fern leaves, giving researchers direct evidence of what this particular dinosaur ate.

The long-necked Nigersaurus from Cretaceous Niger had a broad muzzle with rows of replacement teeth behind those in use. Digital scans helped reveal more than 500 teeth in all. That arrangement let the jaw keep replacing worn teeth and shows how different two sauropods’ feeding equipment could be.

Fossils of very young Maiasaura found in a nest in Montana gave paleontologists evidence about the early lives of duck-billed dinosaurs. Other finds there help fill out the later stages. A set of skulls showed that the crest on top of the head developed relatively late as this dinosaur grew.

The skull of this Late Cretaceous Mongolian dinosaur has a beak and a wide frill behind its head. It belongs to the horned-dinosaur group even though it lacks the showy horns of Triceratops. The combination makes it a good example of how a frill and beak can be recognizable across quite different relatives.

This Late Cretaceous dinosaur has a skull roof that rises into a thick, rounded dome. Researchers have found signs of injury in the domes of several related dinosaurs. The pattern makes head-butting a possibility, while the bones alone leave room for debate about how the animals used their heads.