Science, Tech, Math › Animals & Nature Early Dinosaur Pictures and Profiles Share Flipboard Email Print Animals & Nature Dinosaurs Basics Paleontologists Carnivores Dinosaurs & Birds Herbivores Marine Reptiles Prehistoric Mammals Amphibians Birds Habitat Profiles Mammals Reptiles Insects Marine Life Forestry Evolution View More By Bob Strauss Science Writer B.S., Cornell University Bob Strauss is a science writer and the author of several books, including "The Big Book of What, How and Why" and "A Field Guide to the Dinosaurs of North America." our editorial process Bob Strauss Updated March 20, 2017 01 of 30 Meet the First True Dinosaurs of the Mesozoic Era Tawa. Jorge Gonzalez The first true dinosaurs--small, two-legged, meat-eating reptiles--evolved in what is now South America during the middle to late Triassic period, about 230 million years ago, and then spread around the world. On the following slides, you'll find pictures and detailed profiles of the very first dinosaurs of the Mesozoic Era, ranging from A (Alwalkeria) to Z (Zupaysaurus). 02 of 30 Alwalkeria Alwalkeria (Wikimedia Commons). Name Alwalkeria (after the paleontologist Alick Walker); pronounced AL-walk-EAR-ee-ah Habitat Woodlands of southern Asia Historical Period Late Triassic (220 million years ago) Size and Weight Undisclosed Diet Uncertain; possibly omnivorous Distinguishing Characteristics Bipedal posture; small size All of the available fossil evidence points to middle Triassic South America as being the birthplace of the first dinosaurs--and by the late Triassic period, just a few million years later, these reptiles had spread all over the world. The importance of Alwalkeria is that appears to be an early saurischian dinosaur (that is, it appeared on the scene shortly after the split between "lizard-hipped" and "bird-hipped" dinosaurs), and that it seems to have shared some characteristics with the much earlier Eoraptor from South America. However, there's still a lot we don't know about Alwalkeria, such as whether it was a meat-eater, a plant-eater or an omnivore! 03 of 30 Chindesaurus Chindesaurus. Sergey Krasovskiy Name: Chindesaurus (Greek for "Chinde Point lizard"); pronounced CHIN-deh-SORE-us Habitat: Swamps of North America Historical Period: Late Triassic (225 million years ago) Size and Weight: About 10 feet long and 20-30 pounds Diet: Small animals Distinguishing Characteristics: Relative large size; long legs and long, whiplike tail To demonstrate just how plain-vanilla the first dinosaurs of the late Triassic period were, Chindesaurus was initially classified as an early prosauropod, rather than an early theropod--two very different types of dinosaur that still looked remarkably similar at that relatively early time in evolution. Later, paleontologists determined conclusively that Chindesaurus was a close relative of the South American theropod Herrerasaurus, and probably a descendant of this more famous dinosaur (since there's strong evidence that the first true dinosaurs originated in South America). 04 of 30 Coelophysis Coelophysis. Wikimedia Commons The early dinosaur Coelophysis has had a disproportionate impact on the fossil record: thousands of Coelophysis specimens have been discovered in New Mexico, leading to speculation that these small meat-eaters roamed North America in packs. See 10 Facts About Coelophysis 05 of 30 Coelurus Coelurus. Nobu Tamura Name: Coelurus (Greek for “hollow tail”); pronounced see-LORE-us Habitat: Woodlands of North America Historical Period: Late Jurassic (150 million years ago) Size and Weight: About seven feet long and 50 pounds Diet: Meat Distinguishing Characteristics: Small size; slender hands and feet Coelurus was one of the innumerable genera of small, lithe theropods that scurried across the plains and woodlands of late Jurassic North America. The remains of this tiny predator were discovered and named in 1879 by the famous paleontologist Othniel C. Marsh, but they were later lumped in (incorrectly) with Ornitholestes, and even today paleontologists are unsure exactly what position Coelurus (and its other close relatives, like Compsognathus) occupies on the dinosaur family tree. By the way, the name Coelurus--Greek for "hollow tail"--refers to the lightweight vertebrae in this dinosaur's tailbone. Since the 50-pound Coelurus didn't exactly need to conserve its weight (hollow bones make more sense in huge sauropods), this evolutionary adaptation may well count as additional evidence for the theropod heritage of modern birds. 06 of 30 Compsognathus Compsognathus. Wikimedia Commons Once thought to be the smallest dinosaur, Compsognathus has since been bested by other candidates. But this Jurassic meat-eater shouldn't be taken lightly: it was very fast, with good stereo vision, and perhaps even capable of taking down larger prey. See 10 Facts About Compsognathus 07 of 30 Condorraptor Condorraptor. Wikimedia Commons Name: Condorraptor (Greek for "condor thief"); pronounced CON-door-rap-tore Habitat: Woodlands of South America Historical Period: Middle Jurassic (175 million years ago) Size and Weight: About 15 feet long and 400 pounds Diet: Meat Distinguishing Characteristics: Bipedal stance; medium size Its name--Greek for "condor thief"--may be the best-understood thing about Condorraptor, which was initially diagnosed based on a single tibia (leg bone) until a near-complete skeleton was unearthed a couple of years later. This "small" (only about 400 pound) theropod dates to the middle Jurassic period, about 175 million years ago, a relatively obscure stretch of the dinosaur timeline--so further examination of Condorraptor's remains should shed some much-needed light on the evolution of large theropods. (By the way, despite its name, Condorraptor wasn't a true raptor like the much later Deinonychus or Velociraptor.) 08 of 30 Daemonosaurus Daemonosaurus. Jeffrey Martz Name: Daemonosaurus (Greek for "evil lizard"); pronounced day-MON-oh-SORE-us Habitat: Woodlands of South America Historical Period: Late Triassic (205 million years ago) Size and Weight: About five feet long and 25-50 pounds Diet: Meat Distinguishing Characteristics: Blunt snout with prominent teeth; two-legged posture For over 60 years, the Ghost Ranch quarry in New Mexico was best known for yielding thousands of skeletons of Coelophysis, an early dinosaur of the late Triassic period. Now, Ghost Ranch has added to its mystique with the recent discovery of Daemonosaurus, a comparably sleek, two-legged meat-eater with a blunt snout and prominent teeth lining its upper jaw (hence the species name of this dinosaur, chauliodus, Greek for "buck-toothed"). Daemonosaurus almost certainly preyed on, and was preyed on by turn, by its more famous cousin, though it's uncertain which genus would have had the upper hand (or claw). As primitive as it was compared to later theropods (like raptors and tyrannosaurs), Daemonosaurus was far from the earliest predatory dinosaur. It, and Coelophysis, descended from the very first theropods of South America (like Eoraptor and Herrerasaurus) that lived about 20 million years earlier. However, there are some tantalizing hints that Daemonosaurus was a transitional form between the basal theropods of the Triassic period and the more advanced genera of the ensuing Jurassic and Cretaceous; most notable in this regard were its teeth, which looked like scaled-down versions of T. Rex's massive choppers. 09 of 30 Elaphrosaurus Elaphrosaurus. Wikimedia Commons Name: Elaphrosaurus (Greek for "lightweight lizard"); pronounced eh-LAFF-roe-SORE-us Habitat: Woodlands of Africa Historical Period: Late Jurassic (150 million years ago) Size and Weight: About 20 feet long and 500 pounds Diet: Meat Distinguishing Characteristics: Slender build; fast running speed Elaphrosaurus ("lightweight lizard") comes by its name honestly: this early theropod was relatively svelte for its length, only 500 pounds or so for a body that measured 20 feet from head to tail. Based on its slender build, paleontologists believe Elaphrosaurus was an exceptionally fast runner, though more fossil evidence would help nail down the case (to date, the "diagnosis" of this dinosaur has been based on only one incomplete skeleton). The preponderance of the evidence points to Elaphrosaurus being a close relative of Ceratosaurus, though a shaky case can also be made for Coelophysis. 10 of 30 Eocursor Eocursor. Nobu Tamura Name: Eocursor (Greek for "dawn runner"); pronounced EE-oh-cur-sore Habitat: Woodlands of southern Africa Historical Period: Late Triassic (210 million years ago) Size and Weight: About three feet long and 50 pounds Diet: Probably omnivorous Distinguishing Characteristics: Small size; bipedal gait Toward the end of the Triassic period, the very first dinosaurs--as opposed to prehistoric reptiles like pelycosaurs and therapsids--spread around the world from their home base of South America. One of these, in southern Africa, was Eocursor, the counterpart of fellow progenitor dinosaurs like Herrerasaurus in South America and Coelophysis in North America. The closest relative of Eocursor was probably Heterodontosaurus, and this early dinosaur appears to lie at the root of the evolutionary branch that later gave rise to ornithischian dinosaurs, a category including both stegosaurs and ceratopsians. 11 of 30 Eodromaeus Eodromaeus. Nobu Tamura Name: Eodromaeus (Greek for "dawn runner"); pronounced EE-oh-DRO-may-us Habitat: Woodlands of South America Historical Period: Middle Triassic (230 million years ago) Size and Weight: About four feet long and 10-15 pounds Diet: Meat Distinguishing Characteristics: Small size; bipedal posture As far as paleontologists can tell, it was in middle Triassic South America that the most advanced archosaurs evolved into the very first dinosaurs--small, skittery, bipedal meat eaters that were destined to split off into the more familiar saurischian and ornithischian dinosaurs of the Jurassic and Cretaceous periods. Announced to the world in January of 2011, by a team including the ubiquitous Paul Sereno, Eodromaeus was very similar in appearance and behavior to other "basal" South American dinosaurs like Eoraptor and Herrerasaurus. This small theropod's near-complete skeleton was cobbled together from two specimens found in Argentina's Valle de la Luna, a rich source of Triassic fossils. 12 of 30 Eoraptor Eoraptor. Wikimedia Commons The Triassic Eoraptor displayed many of the generic features of later, more fearsome meat-eating dinosaurs: a bipedal posture, a long tail, five-fingered hands, and a small head filled with sharp teeth. See 10 Facts About Eoraptor 13 of 30 Guaibasaurus Guaibasaurus (Nobu Tamura). Name Guaibasaurus (after the Rio Guaiba Hydrographic Basin in Brazil); pronounced GWY-bah-SORE-us Habitat Woodlands of South America Historical Period Late Triassic (230 million years ago) Size and Weight Undisclosed Diet Unknown; possibly omnivorous Distinguishing Characteristics Slender build; bipedal posture The first true dinosaurs--which evolved about 230 million years ago, during the late Triassic period--preceded the split between ornithischian ("bird-hipped") and saurischian ("lizard-hipped") members of the breed, which has presented some challenges, classification-wise. Long story short, paleontologists can't tell whether Guaibasaurus was an early theropod dinosaur (and thus primarily a meat-eater) or an extremely basal prosauropod, the herbivorous line that went on to spawn the gigantic sauropods of the late Jurassic period. (Both theropods and prosauropods are members of the saurischia.) For now, this ancient dinosaur, discovered by Jose Bonaparte, has tentatively been assigned to the latter category, though more extant fossils would put the conclusion on more solid ground. 14 of 30 Herrerasaurus Herrerasaurus. Wikimedia Commons It's clear from Herrerasaurus' predatory arsenal--including sharp teeth, three-fingered hands, and a bipedal posture--that this ancestral dinosaur was an active, and dangerous, predator of the tiny animals of its late Triassic ecosystem. See an in-depth profile of Herrerasaurus 15 of 30 Lesothosaurus Lesothosaurus. Getty Images Some paleontologists say the small, bipedal, plant-eating Lesothosaurus was a very early ornithopod (which would place it firmly in the ornithischian camp), while others maintain that it predated this important split among the earliest dinosaurs. See an in-depth profile of Lesothosaurus 16 of 30 Liliensternus Liliensternus. Nobu Tamura Name: Liliensternus (after Dr. Hugo Ruhle von Lilienstern); pronounced LIL-ee-en-STERN-us Habitat: Woodlands of Europe Historical Period: Late Triassic (215-205 million years ago) Size and Weight: About 15 feet long and 300 pounds Diet: Meat Distinguishing Characteristics: Five-fingered hands; long head crest As dinosaur names go, Liliensternus doesn't exactly inspire fear, sounding more like it belongs to a gentle librarian than to a fearsome carnivorous dinosaur of the Triassic period. However, this close relative of other early theropods like Coelophysis and Dilophosaurus was one of the largest predators of its time, with long, five-fingered hands, an impressive head crest, and a bipedal posture that must have allowed it to reach respectable speeds in pursuit of prey. It probably fed on relatively small, herbivorous dinosaurs like Sellosaurus and Efraasia. 17 of 30 Megapnosaurus Megapnosaurus. Sergey Krasovskiy By the standards of its time and place, Megapnosaurus (formerly known as Syntarsus) was huge--this early Jurassic dinosaur (which was closely related to Coelophysis) may have weighed as much as 75 pounds fully grown. See an in-depth profile of Megapnosaurus 18 of 30 Nyasasaurus Nyasasaurus. Mark Witton The early dinosaur Nyasasaurus measured about 10 feet from head to tail, which seems enormous by early Triassic standards, except for the fact that fully five feet of that length was taken up by its unusually long tail. See an in-depth profile of Nyasasaurus 19 of 30 Pampadromaeus Wikimedia Commons Name: Pampadromaeus (Greek for "Pampas runner"); pronounced PAM-pah-DRO-may-us Habitat: Woodlands of South America Historical Period: Middle Triassic (230 million years ago) Size and Weight: About five feet long and 100 pounds Diet: Probably omnivorous Distinguishing Characteristics: Small size; long hind legs About 230 million years ago, during the middle Triassic period, the first true dinosaurs evolved in what is now modern-day South America. In the beginning, these small, nimble creatures consisted of basal theropods like Eoraptor and Herrerasaurus, but then an evolutionary shift occurred that gave rise to the first omnivorous and herbivorous dinosaurs, which themselves evolved into the very first prosauropods like Plateosaurus. That's where Pampadromaeus comes in: this newly discovered dinosaur seems to have been intermediate between the very first theropods and the first true prosauropods. Oddly enough for what paleontologists call a "sauropodomorph" dinosaur, Pampadromaeus possessed a very theropod-like body plan, with long hind legs and a narrow snout. The two types of teeth embedded in its jaws, leaf-shaped ones in front and curved ones in back, indicate that Pampadromaeus was a true omnivore, and not yet a devoted plant-muncher like its more famous descendants. 20 of 30 Podokesaurus The type fossil of Podokesaurus. Wikimedia Commons Name: Podokesaurus (Greek for "swift-footed lizard"); pronounced poe-DOKE-eh-SORE-us Habitat: Woodlands of eastern North America Historical Period: Early Jurassic (190-175 million years ago) Size and Weight: About three feet long and 10 pounds Diet: Meat Distinguishing Characteristics: Small size; bipedal posture For all intents and purposes, Podokesaurus can be considered an eastern variant of Coelophysis, a small, two-legged predator that lived in the western U.S. over the Triassic/Jurassic boundary (some experts believe that Podokesaurus was actually a species of Coelophysis). This early theropod had the same long neck, grasping hands, and two-legged posture as its more famous cousin, and it was probably carnivorous (or at the very least an insectivore). Unfortunately, the only fossil specimen of Podokesaurus (which was discovered way back in 1911 in the Connecticut Valley in Massachusetts) was destroyed in a museum fire; researchers have to content themselves with a plaster cast that currently resides at the American Museum of Natural History in New York. 21 of 30 Proceratosaurus Proceratosaurus (Nobu Tamura). Name: Proceratosaurus (Greek for "before Ceratosaurus"); pronounced PRO-seh-RAT-oh-SORE-us Habitat: Plains of Western Europe Historical Period: Middle Jurassic (175 million years ago) Size and Weight: About nine feet long and 500 pounds Diet: Meat Distinguishing Characteristics: Small size; narrow crest on snout When its skull was first discovered--in England way back in 1910--Proceratosaurus was thought to have been related to the similarly crested Ceratosaurus, which lived much later. Today, though, paleontologists identify this middle-Jurassic predator as more similar to small, early theropods like Coelurus and Compsognathus. Despite its relatively small size, the 500-pound Proceratosaurus was one of the biggest hunters of its day, since the tyrannosaurs and other large theropods of the middle Jurassic had yet to attain their maximum sizes. 22 of 30 Procompsognathus Procompsognathus. Wikimedia Commons Because of the poor quality of its fossil remains, all we can say about Procompsognathus is that it was a carnivorous reptile, but beyond that, it's unclear if it was an early dinosaur or a late archosaur (and thus not a dinosaur at all). See an in-depth profile of Procompsognathus 23 of 30 Saltopus Saltopus. Getty Images Name: Saltopus (Greek for "hopping foot"); pronounced SAWL-toe-puss Habitat: Swamps of western Europe Historical Period: Late Triassic (210 million years ago) Size and Weight: About two feet long and a few pounds Diet: Small animals Distinguishing Characteristics: Small size; numerous teeth Saltopus is yet another of those Triassic reptiles that inhabits a "shadow zone" between the most advanced archosaurs and the earliest dinosaurs. Because the single identified fossil of this creature is incomplete, experts differ about how it should be classified, some assigning it as an early theropod dinosaur and others saying it was akin to "dinosauriform" archosaurs like Marasuchus, which preceded the true dinosaurs during the middle Triassic period. Recently, the weight of the evidence points to Saltopus being a late Triassic "dinosauriform" rather than a true dinosaur. 24 of 30 Sanjuansaurus Sanjuansaurus. Nobu Tamura Name: Sanjuansaurus (Greek for "San Juan lizard"); pronounced SAN-wahn-SORE-us Habitat: Woodlands of South America Historical Period: Middle Triassic (230 million years ago) Size and Weight: About five feet long and 50 pounds Diet: Meat Distinguishing Characteristics: Small size; bipedal posture Barring a better hypothesis, paleontologists believe that the first dinosaurs, the early theropods, evolved in South America about 230 million years ago, spawned by a population of advanced, two-legged archosaurs. Discovered recently in Argentina, Sanjuansaurus seems to have been closely related to the better-known basal theropods Herrerasaurus and Eoraptor. (By the way, some experts maintain that these early carnivores weren't true theropods at all, but rather predated the split between saurischian and ornithischian dinosaurs). That's all we know for sure about this Triassic reptile, pending further fossil discoveries. 25 of 30 Segisaurus Segisaurus. Nobu Tamura Name: Segisaurus (Greek for "Tsegi Canyon lizard"); pronounced SEH-gih-SORE-us Habitat: Woodlands of North America Historical Period: Early-Middle Jurassic (185-175 million years ago) Size and Weight: About three feet long and 15 pounds Diet: Meat Distinguishing Characteristics: Small size; strong arms and hands; bipedal posture Unlike its close relative, Coelophysis, fossils of which have been found by the boatload in New Mexico, Segisaurus is known by a single, incomplete skeleton, the only dinosaur remains ever unearthed in Arizona's Tsegi Canyon. Most experts agree that this early theropod pursued a carnivorous diet, though it may have feasted on insects as well as small reptiles and/or mammals. Also, the arms and hands of Segisaurus appear to have been stronger than those of comparable theropods, further evidence for its meat-eating proclivities. 26 of 30 Staurikosaurus Staurikosaurus. Wikimedia Commons Name: Staurikosaurus (Greek for "Southern Cross lizard"); pronounced STORE-rick-oh-SORE-us Habitat: Forests and scrublands of South America HIstorical Period: Middle Triassic (about 230 million years ago) Size and Weight: About six feet long and 75 pounds Diet: Meat Distinguishing Characteristics: Long, thin head; slender arms and legs; five-fingered hands Known from a single fossil specimen discovered in South America in 1970, Staurikosaurus was one of the first dinosaurs, the immediate descendants of the two-legged archosaurs of the early Triassic period. Like its slightly bigger South American cousins, Herrerasaurus and Eoraptor, it seems that Staurikosaurus was a true theropod--that is, it evolved after the ancient split between ornithischian and saurischian dinosaurs. One odd feature of Staurikosaurus is a joint in its lower jaw that apparently allowed it to chew its food backwards and forwards, as well as up and down. Since later theropods (including raptors and tyrannosaurs) didn't possess this adaptation, it's likely that Staurikosaurus, like other early meat-eaters, lived in a stark environment that forced it to extract the maximum nutritional value from its wriggling meals. 27 of 30 Tachiraptor Tachiraptor. Max Langer Name Tachiraptor (Greek for "Tachira thief"); pronounced TACK-ee-rap-tore Habitat Woodlands of South America Historical Period Early Jurassic (200 million years ago) Size and Weight About six feet long and 50 pounds Diet Meat Distinguishing Characteristics Slender build; bipedal posture By now, you'd think paleontologists would know better than to attach the Greek root "raptor" to a dinosaur's name when it's not technically a raptor. But that didn't stop the team behind Tachiraptor, which lived at a time (the early Jurassic period) long preceding the evolution of the first true raptors, or dromaeosaurs, with their characteristic feathers and curved hind claws. The importance of Tachiraptor is that it's not far removed, evolutionarily speaking, from the very first dinosaurs (which appeared in South America a mere 30 million years before), and that it's the first meat-eating dinosaur ever to be discovered in Venezuela. 28 of 30 Tanycolagreus Tanycolagreus. Wikimedia Commons Name: Tanycolagreus (Greek for "elongated limbs"); pronounced TAN-ee-coe-LAG-ree-us Habitat: Woodlands of North America Historical Period: Late Jurassic (150 million years ago) Size and Weight: About 13 feet long and a few hundred pounds Diet: Meat Distinguishing Characteristics: Long, narrow snout; slender build For a decade after its partial remains were discovered in 1995, in Wyoming, Tanycolagreus was thought to be a specimen of another slender meat-eating dinosaur, Coelurus. Further study of its distinctive-looking skull then prompted it to be assigned to its own genus, but Tanycolagreus still remains grouped among the many slender, early theropods that preyed on the small carnivorous and herbivorous dinosaurs of the late Jurassic period. These dinosaurs, as a whole, were not that far evolved from their primitive forebears, the very first theropods that sprang up in South America during the middle Triassic period, 230 million years ago. 29 of 30 Tawa Tawa. Jorge Gonzalez Over and above its presumed resemblance to the later, larger Tyrannosaurus Rex, what's important about Tawa is that it has helped to clear up the evolutionary relationships of the meat-eating dinosaurs of the early Mesozoic Era. See an in-depth profile of Tawa 30 of 30 Zupaysaurus Zupaysaurus. Sergey Krasovskiy Name: Zupaysaurus (Quechua/Greek for "devil lizard"); pronounced ZOO-pay-SORE-us Habitat: Woodlands of South America Historical Period: Late Triassic-Early Jurassic (230-220 million years ago) Size and Weight: About 13 feet long and 500 pounds Diet: Meat Distinguishing Characteristics: Relatively large size; possible crests on head Judging by its single, incomplete specimen, Zupaysaurus appears to have been one of the earliest theropods, the two-legged, carnivorous dinosaurs of the late Triassic and early Jurassic periods that eventually evolved into giant beasts like Tyrannosaurus Rex a hundred million years later. At 13 feet long and 500 pounds, Zupaysaurus was fairly large for its time and place (most other theropods of the Triassic period were about the size of chickens), and based on which reconstruction you believe, it may or may not have had a pair of Dilophosaurus-like crests running down the top of its snout.