Science, Tech, Math › Animals & Nature Meet 80 Meat-Eating Dinosaurs of the Mesozoic Era Pictures and Profiles From Abelisaurus to Yangchuanosaurus Share Flipboard Email Print Animals & Nature Dinosaurs Carnivores Basics Paleontologists Dinosaurs & Birds Herbivores Marine Reptiles Prehistoric Mammals Amphibians Birds Habitat Profiles Mammals Reptiles Wildlife Conservation 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 August 22, 2019 A bewildering array of meat-eating dinosaurs lived during the Mesozoic Era. In this picture gallery with detailed profiles, you'll meet 80 of the world's largest and meanest theropod dinosaurs, ranging from Abelisaurus to Yangchuanosaurus. (Note: The dinosaurs outlined on this page don't include the Tyrannosaur Dinosaurs and Raptor Dinosaur Pictures.) 01 of 80 Abelisaurus (ah-BEEL-ee-sore-us), Abel’s Lizard Kokoo / Wikimedia Commons / CC BY-SA 2.5 The lack of fossil evidence (only a single skull) has forced paleontologists to hazard some guesses about the anatomy of Abelisaurus. It's believed that this meat-eating dinosaur resembled a scaled-down Tyrannosaurus rex, with fairly short arms and a bipedal posture. 02 of 80 Acrocanthosaurus (ak-ro-CAN-tho-SOR-us), Half-Spined Lizard DEA PICTURE LIBRARY / Getty Images Paleontologists are unsure about the function of Acrocanthosaurus' distinctive back ridge. It may have served as a storage place for fat, as a temperature-control device (depending on whether this theropod was cold- or warm-blooded), or as a sexual display. 03 of 80 Aerosteon (AIR-oh-STEE-on), Air Bone Sergey Krasovskiy In most ways, the Aerosteon (about 30 feet long, 1 ton) was a typical predatory dinosaur during the late Cretaceous period with its classic theropod shape (powerful legs, short arms, bipedal stance) and sharp teeth. What sets this meat-eater apart from the pack is the evidence of air sacs in its bones, which globetrotting paleontologist Paul Sereno has taken as evidence that Aerosteon (and, by implication, other theropods of its kind) may have possessed a birdlike respiratory system. (It's important to bear in mind, however, that modern birds evolved not from 1-ton theropods like Aerosteon but from the small, feathered raptors and "dino-birds" of the late Cretaceous.) 04 of 80 Afrovenator (AFF-ro-ven-ay-tore), African Hunter Kabacchi / Wikimedia Commons / CC BY 2.0 Afrovenator (Greek for “African hunter”) and its 30-foot-long body, numerous teeth, and three claws on each hand is significant for two reasons: First, it's one of the few nearly complete theropod (meat-eating dinosaur) skeletons to be unearthed in northern Africa. And second, it appears to have been closely related to the western European Megalosaurus—yet more evidence for the distribution of continents during the early Cretaceous period. However, ever since its discovery, the exact place occupied by Afrovenator in the theropod family tree has been a matter of some controversy. At various times, paleontologists have linked this dinosaur to putative descendants as diverse as Eustreptospondylus, Dubreuillosaurus, Allosaurus, and even the massive Spinosaurus. The situation is complicated by the fact that, to date, Afrovenator is represented by only a single fossil specimen; further digs may shed more light on this dinosaur's affiliations. Since it was one of his earliest discoveries, Afrovenator has become something of a calling card for the noted paleontologist Paul Sereno, who unearthed this dinosaur's bones in the African country of Niger in the early 1990s and carted the remains back to his home base at the University of Chicago. 05 of 80 Allosaurus (AL-oh-SOR-us), Strange Lizard ROGER HARRIS/SCIENCE PHOTO LIBRARY / Getty Images Allosaurus was one of the most common carnivores of the late Jurassic period, a fearsome theropod equipped with sharp teeth and a well-muscled body. This dinosaur also had an especially prominent head, some anatomical features of which may have been meant to attract the opposite sex. 06 of 80 Angaturama (ANG-ah-tore-AH-mah), Noble Kabacchi / Wikimedia Commons / CC BY 2.0 Quick: What other meat-eating dinosaur of the middle Cretaceous period had a sailed back, a long, narrow, crocodilian snout, and a weight class in the Tyrannosaurus rex range? If you answered Spinosaurus, that's pretty much all you need to know about Angaturama (30 feet long, 2 tons), a close (albeit much smaller) relative of Spinosaurus that was unearthed in Brazil in 1991. Brazilian national pride has resulted in the "type fossil" of Angaturama being assigned to its own genus, though some paleontologists speculate that it may actually have been a species of Irritator, yet another spinosaur from South America. 07 of 80 Arcovenator (ARK-oh-ven-ay-tore), Arc Hunter Nobu Tamura The importance of Arcovenator (about 20 feet long and 1,000-2,000 pounds) is that it's one of the few Abelisaurs to have radiated as far afield as western Europe (another example being Tarascosaurus). Note: The Abelisaurs were a breed of medium-to-large size meat-eating dinosaurs that originated in South America toward the middle of the Mesozoic Era and then spread to other parts of the world (while still remaining clustered, for the most part, on their home continent). In any event, this fearsome, 20-foot-long Arcovenator seems to have been most closely related to Majungasaurus from the island of Madagascar and also to Rajasaurus, which was discovered in India. As you can imagine, what this implies for the evolution of Abelisaurs during the late Cretaceous period is still being worked out. 08 of 80 Aucasaurus (OW-cah-SORE-us), Auca Lizard Sergey Krasovskiy To date, not much information has been released about Aucasaurus, a near-complete skeleton of which was discovered in Argentina in 1999. We do know that this carnivorous theropod was closely related to two other famous dinosaurs of South America, Abelisaurus and Carnotaurus, but it was significantly smaller (about 13 feet long and 500 pounds), with longer arms and bumps on its head instead of horns. Based on the dire condition of its skull, it's possible that the only identified specimen of Aucasaurus was done in by a fellow predator, either in a head-on attack or after it had died of natural causes. 09 of 80 Australovenator (AW-strah-low-VEN-ah-tore), Australian Hunter Smokeybjb / Wikimedia Commons / CC BY-SA 3.0 Australovenator was a third of a trio of Australian dinosaurs that had been announced in 2009, the other two being huge, herbivorous titanosaurs. This dinosaur has been classified as an allosaur, a distinctive type of large theropod, and it seems to have been a lightly built, sleek predator (the paleontologist who named it has likened it to a modern cheetah). Australovenator (about 20 feet long and a few hundred pounds) was unlikely to have hunted the 10-ton titanosaurs it was discovered near, but it probably made a good living off the smaller plant eaters of middle Cretaceous Australia. It is now believed that Australovenator was a close relative of the impressively named Megaraptor, a large theropod from South America.) 10 of 80 Bahariasaurus (ba-HA-ree-ah-SORE-us), Oasis Lizard An artist's rendering of Bahariasaurus)extrapolated from a few discovered hipbones. Nobu Tamura The euphoniously named Bahariasaurus ("oasis lizard") might be better known today if its only fossils hadn't been destroyed by an Allied bombing raid on Germany during World War II (the same fate that befell the remains of a much better-known dinosaur, Spinosaurus). What we do know from these long-gone hipbones is that Bahariasaurus was a large theropod (about 40 feet long), possibly attaining Tyrannosaurus rex-like sizes and weights of 6 or 7 tons. As to the evolutionary lineage of Bahariasaurus, that's a murky affair: This dinosaur may have been related to the North African Carcharodontosaurus, it may have been a true tyrannosaur, or it may even have been a species or specimen of the contemporary Deltadromeus. We'll probably never know without additional fossil discoveries. 11 of 80 Baryonyx (bah-ree-ON-icks), Heavy Claw Ballista / Wikimedia Commons / CC BY-SA 3.0 The preserved skeleton of Baryonyx was discovered in 1983 by an amateur fossil hunter in England. It's unclear from the remains just how big this Spinosaurus relative really was. Because the fossil may be of a juvenile, it's possible that Baryonyx grew to larger sizes than previously thought. 12 of 80 Becklespinax (BECK-ul-SPY-nax), Beckles' Spine An artist's rendering of Becklespinax, named after an English fossil hunter. Sergey Krasovskiy One of the most oddly named of all dinosaurs—try saying Becklespinax 10 times fast and keeping a straight face—this large theropod was also one of the most mysterious. It was diagnosed on the basis of three fossilized vertebrae. What is known: It was a respectably sized carnivorous dinosaur (about 20 feet long and weighed 1 ton) of early Cretaceous England, and it may (or may not) have sported a short sail, akin to those of later meat-eaters like Spinosaurus. Judging by the ecosystem in which it lived, Becklespinax probably hunted small- to medium-sized sauropods. 13 of 80 Berberosaurus (BER-ber-oh-SORE-us), Berber Lizard An image of the Berberosaurus based on remains found in Morocco's High Atlas Mountains. Nobu Tamura The early Jurassic period wasn't exactly a hotbed of dinosaur fossils, which is why the moderately sized, bipedal Berberosaurus is so important and so frustrating at the same time. Ever since this theropod was discovered in Morocco’s Atlas Mountains, it has bounced around the classification bins. First, Berberosaurus was pegged as an abelisaur; then as a dilophosaur (that is, a close relative of the better-known Dilophosaurus); and finally, though tentatively, as a ceratosaur. Whatever its ultimate disposition, Berberosaurus was doubtless a fearsome predator, feasting on the smaller theropods and prosauropods of its African habitat. 14 of 80 Bicentenaria (BYE-sen-ten-AIR-ee-ah), 200 Years Lucas-Attwell / Wikimedia Commons / CC BY-SA 4.0 As is often the case in the dinosaur kingdom, the name Bicentenaria is a bit of a misnomer. The scattered remains of this small theropod were actually discovered in 1998, and revealed to the world in an article published in 2012; the 200th anniversary of the country of Argentina actually transpired in between, in 2010. Bicentenaria is important for two reasons. First, this dinosaur was a coelurosaur, that is, a meat-eater closely related to Coelurus. The problem is, Coelurus dated from the late Jurassic period (about 150 million years ago), while the remains of Bicentenaria date to the middle to late Cretaceous period (95 to 90 million years ago). Evidently, while other theropods went merrily about their evolutionary way, developing into plus-sized tyrannosaurs and vicious raptors, Bicentenaria (8 feet long and up to 200 pounds) remained stuck in a Mesozoic time warp. Considering the time and place in which it lived, Bicentenaria was a surprisingly "basal" dinosaur. If it weren't for the unmistakable sediments in which it was buried, paleontologists might be forgiven for believing that it lived 50 million years earlier than it actually did. 15 of 80 Carcharodontosaurus (kar-KA-ro-DON-toe-SOR-us), Shark-Toothed Lizard This image compares the size of an adult human with an adult Carcharodontosaurus. Sameer Prehistorica The type fossil of Carcharodontosaurus, the "Great White Shark lizard," was destroyed during an Allied bombing raid on Germany in World War II, the same fate that befell the bones of this dinosaur's close relative, Spinosaurus, also of northern Africa. 16 of 80 Carnotaurus (CAR-no-TOR-us), Meat-Eating Bull MR1805 / Getty Images The arms of Carnotaurus were small and stubby enough to make those of the Tyrannosaurus rex seem gigantic by comparison, and the horns over its eyes were too small to be of much use—odd features that make Carnotaurus easily distinguishable from other large meat-eating dinosaurs of the late Cretaceous period. 17 of 80 Ceratosaurus (seh-RAT-o-SOR-us), Horned Lizard Elenarts / Getty Images Wherever it's ultimately assigned on the theropod family tree, Ceratosaurus was a fierce predator, gobbling up pretty much anything that came across its path—fish, marine reptiles, and other dinosaurs. This carnivore had a more flexible tail than others of its kind, presumably making it an agile swimmer. 18 of 80 Chilantaisaurus (chi-LAN-tie-SORE-us), Chilantai Lizard DEA PICTURE LIBRARY / Getty Images A bewildering array of large theropods roamed the woodlands of Eurasia during the early to mid-Cretaceous period. Among the biggest of the bunch was Chilantaisaurus (about 25 feet long, 4 tons), only about half the size of a full-grown Tyrannosaurus rex—which lived tens of millions of years later but was still impressive. Chilantaisaurus was once thought to be closely related to the slightly earlier Allosaurus of North America, but it now seems that it may have been an early member of the line of carnivorous dinosaurs that went on to produce the truly gigantic Spinosaurus. 19 of 80 Concavenator (con-KAH-veh-NAY-tuhr), Cuenca Hunter Corey Ford/Stocktrek Images / Getty Images The meat-eating dinosaur Concavenator sported two extremely odd adaptations: a triangular structure on its lower back that may have supported a sail or fatty hump, and what appeared to be "quill knobs" on its forearms, bony structures that probably supported small arrays of feathers. 20 of 80 Cruxicheiros (CREW-ksih-CARE-oss), Crossed Hand An artist's rendering of the Cruxicheiros based on remains found in England. Sergey Krasovskiy If the Cruxicheiros fossil had been discovered 200 years ago, this large-sized dinosaur would no doubt have been classified as a species of Megalosaurus. As it is, though, this dinosaur's bones were dredged from an English quarry in the early 1960s, and it was only assigned to its own genus in 2010. (Note: The name Cruxicheiros, "crossed hands," doesn't refer to this meat eater's posture, but to the Cross Hands quarry in Warwickshire, England.) Beyond that, not a whole lot is known about Cruxicheiros besides its very general classification as a "tetanuran" theropod, meaning it was related to virtually every other meat-eating dinosaur of the Mesozoic Era. 21 of 80 Cryolophosaurus (cry-o-LOAF-o-SOR-us), Cold-Crested Lizard Corey Ford/Stocktrek Images / Getty Images The meat-eating dinosaur Cryolophosaurus stands out for two reasons: It was an early carnosaur, predating others of its kind by tens of millions of years, and it had a strange crest atop its head that ran from ear to ear, rather than from front to back, like an Elvis Presley pompadour. 22 of 80 Dahalokely (dah-HAH-loo-KAY-lee), Small Bandit Danny Cicchetti / Wikimedia Commons / CC BY-SA 3.0 The importance of Dahalokely (which was announced to the world in 2013) is that this meat-eating dinosaur lived 90 million years ago, shaving about 20 million years off the far end of Madagascar's almost 100-million-year fossil gap. 23 of 80 Deltadromeus (DELL-tah-DROE-mee-us), Delta Runner Kabacchi / Wikimedia Commons / CC BY 2.0 It's hard to picture a carnivorous dinosaur measuring over 30 feet from snout to tail and weighing in the neighborhood of 3 to 4 tons building up a significant head of steam during a chase, but judging by its streamlined build, Deltadromeus must have been one of the fastest and most dangerous predators of the middle Cretaceous period. Not long ago, this large theropod was classified as a coelurosaur (a family of fairly small, predatory dinosaurs), but its size and other anatomical characteristics have since placed it more firmly in the ceratosaur camp, and thus closely related to the equally dangerous Ceratosaurus. 24 of 80 Dilophosaurus (die-LOAF-o-SOR-us), Two-Ridged Lizard Suwatwongkham / Getty Images Thanks to its portrayal in "Jurassic Park," Dilophosaurus may be the most misunderstood dinosaur on the face of the earth: it didn't spit poison, it didn't have an expandable neck frill, and it wasn't the size of a Golden retriever. 25 of 80 Dubreuillosaurus (doo-BRAIL-oh-SORE-us), Dubreuill's Lizard Nobu Tamura / Wikimedia Commons / CC BY 3.0 Not the most easily spelled (or pronounced) dinosaur, Dubreuillosaurus was only diagnosed in 2005 on the basis of a partial skeleton (it was originally thought to have been a species of the even more obscure meat-eater Poekilopleuron). Now classified as a megalosaur, a type of large theropod closely related to Megalosaurus, Dubreuillosaurus (25 feet long and 2 tons) was characterized by its unusually long skull, which was three times as long as it was thick. It's unknown exactly why this theropod evolved this feature, but it probably had something to do with its accustomed diet during the Jurassic period. 26 of 80 Duriavenator (DOOR-ee-ah-VEN-ay-tore), Dorset Hunter Sergey Krasovskiy/Stocktrek Images / Getty Images Paleontologists don't always spend their time out in the field digging up new dinosaurs. Sometimes they have to rectify the errors made by previous generations of scientists. Duriavenator is the genus name assigned in 2008 to what had previously been classified as a species of Megalosaurus, M. hesperis. (In the mid-19th century, a bewildering variety of theropods were classified as Megalosaurus by paleontologists who hadn't yet grasped the full scope of theropod evolution.) The middle Jurassic Duriavenator is one of the earliest identified tetanuran ("stiff-tailed") dinosaurs, preceded (perhaps) only by Cryolophosaurus. 27 of 80 Edmarka (ed-MAR-ka), Named in Honor of Paleontologist Bill Edmark Sergey Krasovskiy / Getty Images Just how confident was the famous paleontologist Robert Bakker when the discovered the fossils of Edmarka in the early 1990s? Well, he dubbed this presumed new species of large theropod Edmarka rex, after its more famous cousin of the late Cretaceous period, Tyrannosaurus rex. The trouble is, most paleontologists believe that Edmarka rex was actually in the genus Torvosaurus. Whatever you choose to call it, Edmarka (35 feet long and 2-3 tons) was clearly an apex predator of late Jurassic North America, and one of the scariest predatory dinosaurs until the advent of full-sized tyrannosaurs tens of millions of years later. 28 of 80 Ekrixinatosaurus (eh-KRIX-ih-NAT-oh-SORE-us), Explosion-Born Lizard Sergey Krasovskiy/Stocktrek Images/Getty Images The most interesting thing about some dinosaurs is their names. That's certainly the case with Ekrixinatosaurus, a nearly unpronounceable jumble of Greek roots that translates roughly as "explosion-born lizard." It's a reference to the fact that this large theropod's bones were discovered during construction-related blasting in Argentina, and which has nothing to do with the extinction of the dinosaurs 65 million years ago. Ekrixinatosaurus (about 20 feet long and weighing 1 ton) is classified as an abelisaur (and hence a relative of Abelisaurus), and it also shared some characteristics (such as its unusually tiny and stunted arms) with the better-known Majungatholus and Carnotaurus. 29 of 80 Eoabelisaurus (EE-oh-ah-BELL-ih-SORE-us), Dawn Abelisaurus Conty / Wikimedia Commons / CC BY-SA 3.0 The abelisaurids were a family of meat-eating dinosaurs that populated South America during the Cretaceous period (the most famous member of the breed was Carnotaurus). The importance of Eoabelisaurus is that it's the first identified abelisaurid theropod to date from the Jurassic period, about 170 million years ago, an otherwise sparse stretch of time for dinosaur discoveries. Like its descendants, tens of millions of years down the line, this "dawn Abelisaurus" (about 20 feet long and 1-2 tons) was characterized by its fearsome size (at least by middle Jurassic standards) and its unusually stunted arms, which doubtless still served some useful purpose. 30 of 80 Eocarcharia (EE-oh-car-CAR-ee-ah), Dawn Shark Nobumichi Tamura/Stocktrek Images/Getty Images As you may have guessed from its name, Eocarcharia was closely related to Carcharodontosaurus, the "great white shark lizard" that occupied the same north African habitat. Eocarcharia (25 feet long and 1,000 pounds) was smaller than its more famous cousin. It also had a strange, bony ridge over its eyes, which it may have used to head-butt other dinosaurs (this was probably a sexually selected characteristic, meaning males with bigger, bonier brows got to mate with more females). Judging by its numerous, sharp teeth, Eocarcharia was an active predator, though it presumably left the biggest prey to Carcharodontosaurus. By the way, this large theropod marks yet another notch in the dinosaur-discovery belt of the prolific paleontologist Paul Sereno. 31 of 80 Erectopus (eh-RECK-toe-puss), Upright Foot Erectopus drawing based on bones found in eastern France. Nobu Tamura To those unfamiliar with the Greek language, the name Erectopus may seem slightly naughty—but it actually means nothing more titillating than "upright foot." The remains of this meat-eating dinosaur were discovered in France in the late 19th century, and since then it has had a complicated taxonomic history. Like many carnivores of dubious provenance, this dinosaur which was about 10 feet long and weighed 500 pounds, was initially classified as a species of Megalosaurus (M. superbus), then renamed Erectopus sauvagei by the German paleontologist Friedrich von Huene. After that, it spent almost the next 100 years in dinosaur limbo, until it was reassessed in 2005 as a close (but much smaller) relative of Allosaurus. 32 of 80 Eustreptospondylus (yoo-STREP-to-SPON-di-luss), True Streptospondylus Model of Eustreptospondylus based on remains found in southern England. Ballista / Wikimedia Commons / CC BY-SA 3.0 Eustreptospondylus was discovered in the mid-19th century before scientists had developed a suitable system for classifying dinosaurs. As a result, this theropod was originally thought to be a species of Megalosaurus, and it took a full century for paleontologists to assign it to its own genus. 33 of 80 Fukuiraptor ( FOO-kwee-rap-tore), Fukui Thief Titomaurer / Wikimedia Commons / CC BY-SA 4.0 Like many theropods (the large family of two-legged carnivorous dinosaurs that included such diverse groups as raptors, tyrannosaurs, carnosaurs, and allosaurs), Fukuiraptor (about 13 feet long and about 300 pounds) has bounced around the classification bins ever since its discovery in Japan. At first, this dinosaur's giant hand claws were misidentified as belonging on its feet, and it was classified as a raptor (a legacy that endures in its name). Today, though, Fukuiraptor is believed to have been a carnosaur and was probably closely related to another misnamed, medium-size theropod, the Chinese Sinraptor. During the middle Cretaceous period, it's possible that Fukuiraptor preyed on the contemporary ornithopod Fukuisaurus, but as yet, there's no evidence for this. 34 of 80 Gasosaurus (GAS-o-SOR-us), Gas Lizard Skeleton of Gasosaurus, a dinosaur that once lived in what is now the woodlands of China. Finblanco / Wikimedia Commons / Public Domain Why "Gasosaurus?" Not because this dinosaur had digestive issues but because the fragmented remains of this obscure but amusingly named theropod were discovered in 1985 by the employees of a Chinese gas-mining company. 35 of 80 Genyodectes (JEN-yo-DECK-teez), Jaw Biter J. Green / Wikimedia Commons / Public Domain Considering that entire dinosaurs have been reconstructed from scarcer fossil evidence, it seems odd that Genyodectes has proven so hard to classify. This meat-eater is represented by a single, superbly preserved set of choppers, which look like the giant-sized false teeth from a children's cartoon. Since its type fossil was described in 1901, Genyodectes has been classified as a tyrannosaur, an abelisaur, and a megalosaur. Lately, the trend has been to lump it in with the ceratosaurs, which would make it a close relative of Ceratosaurus. Oddly enough, considering its tangled history, Genyodectes was the most well-attested large South American theropod until a series of spectacular fossil finds starting in the 1970s. 36 of 80 Giganotosaurus (JIG-an-OH-toe-SOR-us), Giant Southern Lizard Jeff Kubina/Wikimedia Commons/CC BY-SA 2.0 Giganotosaurus was a truly enormous predatory dinosaur, slightly outweighing even Tyrannosaurus rex. This South American theropod also had a more formidable arsenal, including much bigger arms with three clawed fingers on each hand. 37 of 80 Gojirasaurus (go-GEE-rah-SORE-us), Godzilla Lizard Sergey Krasovskiy/Stocktrek Images/Getty Images Here's a quick Japanese lesson: The enormous monster we know as Godzilla bears the Japanese name Gojira, which is itself a combination of the Japanese words for whale kujira and gorilla gorira. As you can guess, the paleontologist who named Gojirasaurus (the bones of which were dug up in North America) grew up as a die-hard fan of the "Godzilla" movies. Despite its name, Gojirasaurus (18 feet long and 500 pounds) was far from the biggest dinosaur that ever lived, though it did attain a respectable size for its time. It may have been one of the biggest theropods of the Triassic period. So far, paleontologists have only found the fossil of a single juvenile, so it's possible that adults of this genus may have been even bigger (though nowhere near as massive as later carnivorous dinosaurs like Tyrannosaurus rex, much less Godzilla). 38 of 80 Ilokelesia (EYE-low-keh-LEE-zha), Flesh Lizard Danny Cicchetti/Wikimedia Commons/CC BY-SA 3.0 Ilokelesia (about 14 feet long) was one of a wide variety of abelisaurs—small- to medium-sized theropod dinosaurs closely related to Abelisaurus—that inhabited South America during the middle to late Cretaceous period. This 500-pound meat-eater stood out from the pack thanks to its broader-than-usual tail and the structure of its skull. Its closest relative was the much bigger and much more dangerous Mapusaurus. There's still a lot that paleontologists don't know about the evolutionary relationship of abelisaurs to other theropod families, which is why dinosaurs like Ilokelesia are a subject of intensive study. 39 of 80 Indosuchus (IN-doe-SOO-kuss), Indian Crocodile DEA PICTURE LIBRARY / Getty Images As you may have guessed from its name, Indian crocodile, Indosuchus wasn't identified as a dinosaur when its scattered remains were first discovered in 1933, in southern India (which, even today, is not exactly a hotbed of dinosaur research). It was only much later that this 20-foot-long creature was reconstructed as a large theropod, closely related to the South American Abelisaurus, and thus a devoted hunter of the small- to mid-sized hadrosaurs and titanosaurs of late Cretaceous central Asia. The Indosuchus kinship with a South American dinosaur can no doubt be explained by the distribution of the Earth's continents during the Mesozoic Era. 40 of 80 Irritator (IH-rih-tay-tore), The irritating One Sergey Krasovskiy / Getty Images As spinosaurs—large, carnivorous dinosaurs with crocodile-like heads and jaws—the Irritator (about 25 feet long and weighing 1 ton) wasn't any more "irritating" than any other genus. Rather, this predator acquired its name because its only existing skull had been touched up with plaster by an overeager fossil hunter, requiring paleontologist Dave Martill to spend long, tedious hours undoing the damage. As you may already have guessed, Irritator was closely related to its fellow South American theropod Spinosaurus, the biggest carnivorous dinosaur that ever lived—and it may yet wind up being assigned as a species of yet another South American spinosaur, Angaturama. Note: The last name of the only known species of Irritator is "challengeri," after the lead character in Sir Arthur Conan Doyle's novel "The Lost World." 41 of 80 Kaijiangosaurus (KY-jee-ANG-oh-SORE-us), Kaijiang Lizard A representation of the Kaijiangosaurus, discovered in China. Sergey Krasovskiy Kaijiangosaurus (13 feet long and 500 pounds) from the late Jurassic period is one of those dinosaurs that has been consigned to the "almost, but not quite" netherworld of paleontology. This large theropod (technically, a carnosaur) was discovered in China in 1984, in the same formation that yielded the better known, and much more amusingly named, Gasosaurus. In fact, most paleontologists believe that Kaijiangosaurus was either a specimen or a species of this more famous dinosaur, which wasn't technically gassy but discovered during a dig on gas-bearing sediments. Only further fossil discoveries can decide the issue one way or the other. 42 of 80 Kryptops (CRIP-tops), Covered Face Nobumichi Tamara/Stocktrek Images/Getty Images Discovered in 2008 by the globe-trotting paleontologist Paul Sereno, Kryptops is a rare example of a North African theropod (technically an abelisaur) from the middle Cretaceous period. This dinosaur wasn't especially big, "only" about 25 feet long and less than a ton, but it was distinguished by the weird, horny skin that seemed to have covered its face (this coating was probably made of keratin, the same stuff as human fingernails). Despite its fearsome appearance, Kryptops' relatively short, blunt teeth point to its having been a scavenger rather than an active hunter. 43 of 80 Leshansaurus (LEH-shan-SORE-us), Leshan Lizard Drawing of Leshansaurus based on fossils from China. Nobu Tamura To date, not a lot is known about the Leshansaurus (about 20 feet long, 1 ton), which was described on the basis of a partial juvenile skeleton unearthed in China's Dashanpu Formation in 2009. Initially, this theropod was classified as a close relative of Sinraptor, but there are some indications that it may have been a megalosaur instead (and thus similar to the western European Megalosaurus). Leshansaurus did possess an unusually narrow snout, which has fueled speculation that it preyed on the small, more easily tipped-over ankylosaurs of late Cretaceous China (such as Chialingosaurus). 44 of 80 Limusaurus (LIH-moo-SORE-us), Mud Lizard Conty / Wikimedia Commons / Public Domain Every now and then, paleontologists unearth a dinosaur that throws a big, looping curveball into accepted dogma. That's what has happened with Limusaurus (about 5 feet long, 75 pounds), a very early ceratosaur (a type of large theropod, or bipedal, meat-eating dinosaur) with a beaked snout and no teeth. What this almost certainly means (though not all paleontologists have accepted this conclusion) is that Limusaurus was more likely a vegetarian, whereas virtually all other theropod genera (with the exception of some therizinosaurs and ornithomimids) are known to have subsisted on meat. As such, this relatively early (late Jurassic) ceratosaur may have represented a transitional form between earlier vegetarians and later carnivores. 45 of 80 Lourinhanosaurus (lore-in-HAHN-oh-SORE-us), Lourinha Lizard Cancelos / Wikimedia Commons / CC BY-SA 3.0 One of the few large theropods to be discovered in Portugal, Lourinhanosaurus (about 20 feet long and a couple of tons) was named after that country's Lourinha Formation, and it has proven difficult to classify. Paleontologists can't decide if it was most closely related to Allosaurus, Sinraptor or the equally obscure Megalosaurus. This late Jurassic predator is noteworthy for two reasons: First, scientists have identified gastroliths among its fossilized stomach contents, which Lourinhanosaurus clearly swallowed on purpose rather than ingesting by accident when eating herbivorous dinosaurs. And second, a clutch of about 100 Lourinhanosaurus eggs, some containing fossilized embryos, have been found close to the original excavation site. 46 of 80 Magnosaurus (MAG-no-SORE-us), Large Lizard Nobumichi Tamura/Stocktrek Images/Getty Images Paleontologists are still untangling the confusion generated by the early discovery (in 1676) of Megalosaurus, after which every dinosaur that vaguely resembled it was assigned, incorrectly, to its genus. A good example is Magnosaurus, which (based on its limited fossil remains) was considered to be a valid species of Megalosaurus until years later. Apart from this taxonomic confusion, Magnosaurus appears to have been a typical theropod of the middle Jurassic period, relatively small (about 13 feet long and 400 pounds or so) and speedy compared to its later Jurassic and Cretaceous descendants. 47 of 80 Majungasaurus (mah-JOON-guh-SOR-us), Majunga Lizard Stocktrek Images / Getty Images Paleontologists have identified Majungasaurus bones bearing Majungasaurus tooth marks. However, we don't know whether adults of this dinosaur genus actively hunted down their relatives or if they simply feasted on the carcasses of already dead family members. 48 of 80 Mapusaurus (MAH-puh-SOR-us), Earth Lizard Kabacchi/Wikimedia Commons/CC BY 2.0 The discovery of hundreds of Mapusaurus bones jumbled together can be taken as evidence of herd or pack behavior—raising the possibility that this meat-eating dinosaur hunted cooperatively in order to take down the huge titanosaurs of middle Cretaceous South America. 49 of 80 Marshosaurus (MARSH-oh-SORE-us), Marsh's Lizard Sergey Krasovskiy/Stocktrek Images/Getty Images Marshosaurus didn't earn its name because it lived in a marshy habitat; rather, it honors the famous paleontologist Othniel C. Marsh, who's also memorialized by another dinosaur genus (Othnielia, sometimes called Othnielosaurus). Beyond its illustrious name, Marshosaurus (20 feet long, 1,000 pounds) appears to have been a typical, medium-sized theropod of the late Jurassic period and is represented by very limited fossil remains. This would no doubt displease Marsh, a famously prickly figure who spent much of the 19th century feuding with his contemporary, Edward Drinker Cope, on a dark page of dinosaur history known as the Bone Wars. 50 of 80 Masiakasaurus (MAY-zha-kah-SORE-us), Vicious Lizard CoreyFord/Getty Images If ever a dinosaur needed braces, it was the Masiakasaurus. The teeth of this smallish theropod (6 feet long, 100-200 pounds) were angled outward toward the front of its mouth, an adaptation that presumably evolved for a good reason. The most likely explanation is that Masiakasaurus subsisted on fish, which it speared with its front choppers. Then again, maybe this particular individual simply needed to take a trip to a Cretaceous orthodontist. Masiakasaurus is notable for another reason: The only known species, Masiakasaurus knopfleri, is named after former Dire Straits frontman Mark Knopfler, for the simple reason that Knopfler's music happened to be playing when this fossil was unearthed on the Indian Ocean island of Madagascar. 51 of 80 Megalosaurus (MEG-a-lo-SOR-us), Great Lizard MR1805/Getty Images Megalosaurus has the distinction of being the first dinosaur ever to appear in a work of fiction. A century before the Hollywood era, Charles Dickens name-dropped this dinosaur in his novel "Bleak House." He wrote, "It would not be wonderful to meet a Megalosaurus, 40 feet long or so, waddling like an elephantine lizard up Holborn Hill." 52 of 80 Megaraptor (meg-a-RAP-tor), Giant Plunderer Sergey Krasovskiy/Getty Images When the scattered remains of Megaraptor were discovered in Argentina in the late 1990s, paleontologists were impressed by a single, foot-long claw, which they incorrectly assumed was located on this dinosaur's hind foot—hence its initial classification as a raptor. 53 of 80 Metriacanthosaurus (MEH-tree-ah-CAN-tho-SORE-us), Moderate-Spined Lizard De Agostini Picture Library / Getty Images Not the most euphoniously named of all dinosaurs, Metriacanthosaurus ("moderate-spined lizard") was mistakenly classified as a species of Megalosaurus when its incomplete fossil remains were discovered in England in 1923—not an uncommon occurrence, since many large theropods of the late Jurassic period started out under the Megalosaurus umbrella. We still don't know a whole lot about this 25-foot-long dinosaur, except it probably weighed about a ton and that the short spines jutting out from its vertebrae may have supported a slender hump or sail—a hint that Metriacanthosaurus was perhaps ancestral to more famous sailed carnivores like the much later Spinosaurus. 54 of 80 Monolophosaurus (MON-oh-LOAF-oh-SORE-us), Single-Crested Lizard Kabacchi/Wikimedia Commons/CC BY 2.0 Unlike its similarly named cousin, Dilophosaurus, Monolophosaurus (about 17 feet long, 1,500 pounds) hasn't quite seized the public's imagination—even though this allosaur (as it has tentatively been classified) was slightly bigger than Dilophosaurus and probably more dangerous. Like all theropods, Monolophosaurus was a meat-eating biped, and judging by geological clues from where it was discovered, it likely prowled the lake beds and riversides of middle Jurassic Asia. Why did Monolophosaurus have that single, prominent crest on top of its head? As with all such anatomical features, this was likely a sexually selected characteristic—that is, males with bigger crests were dominant in the pack and could more easily mate with females. 55 of 80 Neovenator (KNEE-oh-ven-ate-or), New Hunter Fred Wierum/Wikimedia Commons/CC BY-SA 4.0 For all intents and purposes, Neovenator (25 feet long and weighing a half ton) occupied the same niche in its western European habitat as Allosaurus did in North America: a large, agile, fast and fearsome theropod that predated the much bigger tyrannosaurs of the later Cretaceous period. Neovenator is probably the best-known and most popular carnivorous dinosaur from western Europe, which (until the discovery of this genus in 1996) had to make do with historically important but frustratingly vague meat-eaters like Megalosaurus. (By the way, Neovenator was closely related to the impressively named Megaraptor of South America, which wasn't technically a true raptor but another large theropod of the Allosaurus family.) 56 of 80 Ostafrikasaurus (oss-TAFF-frih-kah-SORE-us), East Africa Lizard PaleoGeekSquared/Wikimedia Commons/CC BY-SA 4.0 No paleontologist likes to erect a new dinosaur genus on the basis of a handful of teeth, but sometimes that's all there is to go on, and you have to make the best of the situation. Ostafrikasaurus has bounced all over the classification bins since its discovery in Tanzania in the early 20th century. First, it was assigned to Labrosaurus (which turned out to be the same dinosaur as Allosaurus), then to Ceratosaurus, and then to an early spinosaur closely related to Spinosaurus and Baryonyx. If this last identification holds, then Ostafrikasaurus will prove to be the earliest spinosaur in the fossil record, dating to the late Jurassic (rather than the early to middle Cretaceous) period. 57 of 80 Oxalaia (OX-ah-LIE-ah), Named After a Brazilian Deity PaleoGeekSquared/Wikimedia Commons/CC BY-SA 4.0 If paleontologists had discovered Oxalaia's arm or leg, rather than pieces of its long, narrow snout, they probably wouldn't have been able to classify this dinosaur. As things stand, though, Oxalaia was clearly a genus of spinosaur, the family of plus-sized meat eaters characterized by their crocodile-ish jaws and (in some species) the sails on their backs. To date, the Oxalaia (about 40 feet long and 6 tons) is the largest spinosaur to be discovered in South America, bigger than its continent-mates Irritator and Angaturama but slightly smaller than African spinosaurs like Suchomimus and (of course) Spinosaurus. 58 of 80 Piatnitzkysaurus (pyat-NIT-skee-SORE-us), Piatnitzsky's Lizard De Agostini Picture Library / Getty Images It's hard to work up much of a sweat about a dinosaur named "Piatnitzky," but the fierce carnivore Piatnitzkysaurus (14 feet long, 1,000 pounds) terrorized the plant-eaters of middle Jurassic South America. Closely related to another early theropod, Megalosaurus, Piatnitzkysaurus was distinguished by the crests on its head and its long, stiff tail, which it probably used for balance when chasing down prey. It clearly partook of the same body plan as later, bigger, and more dangerous theropods like Allosaurus and Tyrannosaurus rex. 59 of 80 Piveteausaurus (PIH-veh-toe-SORE-us), Named After French Paleontologist Jean Piveteau Jordan Mallon/Wikimedia Commons/CC BY-SA 2.5 As with many dinosaurs, the main reason Piveteausaurus (about 25 feet long, 1 ton) isn't better known is that it has been mired in controversy ever since its discovery, and naming, nearly a century ago. The fossils of this sizable theropod have been variously assigned to Streptospondylus, Eustreptospondylus, Proceratosaurus, and even Allosaurus. The only body part that seems to belong to Piveteausaurus is a fragment of the braincase, and even that is the subject of some dispute. What we do know about this dinosaur is that it was a fearsome predator of middle to late Jurassic Europe and possibly the apex reptile of its local French ecosystem. 60 of 80 Poekilopleuron (PEEK-i-lo-PLOOR-on), Varied Ribs Tiia Monto / Wikimedia Commons / CC BY-SA 4.0 After its discovery in the early 19th century, Poekilopleuron was examined by an almost comical array of famous paleontologists, none of whom could quite come to terms about how this meat-eating dinosaur should be classified. 61 of 80 Rahiolisaurus (RAH-hee-OH-lih-SORE-us), Named After a Village in India Paleocolour/WIkimedia Commons/CC BY-SA 3.0 Thanks to the vagaries of the fossilization process, very few dinosaurs have been discovered in India, the chief culprits being moderately sized "abelisaur" theropods like Indosuchus and strange-looking sauropods like Isisaurus. Unusually, the Rahiolisaurus (about 25 feet long, 1 ton) is represented by seven incomplete, tangled specimens, which may have drowned in a flash flood or even dragged to this location by scavengers after they died during the late Cretaceous. The main thing that distinguished this meat eater from its close contemporary Rajasaurus is that it was relatively slender or gracile, rather than thickly built or robust. Other than that, we know very little about its appearance or how it lived. 62 of 80 Rajasaurus (RAH-jah-SORE-us), The Prince Lizard Corey Ford/Stocktrek Images/Getty Images An otherwise unremarkable meat-eating dinosaur, except for its small head crest, Rajasaurus (30 feet long, 1 ton) lived in what is now modern-day India. Dinosaur fossils are relatively rare on the subcontinent, which is why the regal word "raja" was bestowed on this predator. 63 of 80 Rugops (ROO-gops), Wrinkled Face Sergey Krasovskiy/Stocktrek Images/Getty Images When it was discovered in North Africa in 2000 by the famous paleontologist Paul Sereno, the skull of Rugops stood out for two reasons. First, the teeth were fairly small and unimpressive, hinting that this large theropod (30 feet long, 2-3 tons) may have feasted on already dead carcasses rather than hunting live prey. And second, the skull is pitted with unusual lines and holes, which likely indicates the presence of armored skin and/or a fleshy display (like the wattle of a chicken) on this dinosaur's head. Rugops is also an important find because it provides evidence that, during the middle Cretaceous period, Africa was still attached by a land bridge to the northern supercontinent of Gondwana (whence other abelisaurs of Rugops' theropod family hailed, most notably the South American Abelisaurus). 64 of 80 Sauroniops (sore-ON-ee-ops), Eye of Sauron 08pateldan/Wikimedia Commons/CC BY-SA 3.0 Sometimes, the name a dinosaur is given is inversely proportional to how much we know about it. The impressively named Sauroniops ("eye of Sauron," after the evil overlord in the "Lord of the Rings" trilogy) is represented in the fossil record by—wait for it—a single fragment of its skull, a 6-inch-long "frontal," complete with an odd bulge on top, situated just above this dinosaur's eye socket. Fortunately for the paleontologists who examined this remnant—which was originally in the possession of an unidentified Moroccan fossil dealer—this bit of a theropod dinosaur's skull is very characteristic, especially since these meat-eating dinosaurs weren't exactly thick on the ground in late Cretaceous northern Africa. Clearly, the fossil belonged to a dinosaur closely related to the well-known Carcharodontosaurus and the not-quite-as-well-known Eocarcharia. Was Sauroniops truly the "Lord of the Dinosaurs"? Well, this theropod was clearly a good match for Carcharodontosaurus, measuring about 30 feet from head to tail and tipping the scales at upward of 2 tons. Aside from that, though, it remains a mystery—even that bump on its head, which may have functioned as a sexually selected characteristic (say, changing color during mating season), or it may be a clue that Sauroniops males head-butted each other for dominance in the pack. 65 of 80 Saurophaganax (SOR-o-FAG-uh-naks), King of the Lizard Eaters Chris Dodds/Wikimedia Commons/CC BY-SA 2.0 The most notable reconstruction of Saurophaganax, at a museum in Oklahoma City, uses fabricated, scaled-up bones derived from Allosaurus, the meat-eating dinosaur this theropod most closely resembled. 66 of 80 Siamosaurus (SIE-ah-moe-SORE-us), Siamese Lizard FunkMonk/Wikimedia Commons/CC BY-SA 3.0 It's true that many dinosaurs are diagnosed on the basis of a single, fossilized tooth—but it's also true that many of these dinosaurs are looked on dubiously by other paleontologists, who require more convincing evidence. That's the case with Siamosaurus (about 30 feet long and 2-3 tons), which in 1986 was touted by its discoverers as the very first spinosaur (i.e., Spinosaurus-like theropod) ever to be discovered in Asia. (Since then, a comparably sized and better-attested spinosaur, Ichthyovenator, has been unearthed in Laos.) If Siamosaurus was in fact a spinosaur, it probably spent most of its day on the banks of rivers hunting for fish—and if it wasn't, then it may well have been another type of large theropod with a more diverse diet. 67 of 80 Siamotyrannus (SIGH-ah-mo-tih-RAN-us), Siamese Tyrant An artist's colorful depiction of Siamotyrannus. Sergey Krasovskiy You might assume from its name that Siamotyrannus (20 feet long, 1,000-2,000 pounds) was an Asian contemporary and close relative of Tyrannosaurus rex, but the fact is that this large theropod lived tens of millions of years before its more famous namesake—and is considered by most paleontologists to be a carnosaur rather than a true tyrannosaur. One of the few dinosaurs of any kind to be unearthed in modern-day Thailand, Siamotyrannus will have to be supported by more fossil discoveries before it takes up more than a footnote in the official theropod record books. 68 of 80 Siats (SEE-atch), Named After a Mythical Native American Monster A colorful artist rendition of a fierce-looking Siats. Jorge Gonzalez Don't believe what you read in the popular press about Siats "terrorizing" or "beating down" Tyrannosaurus rex. The fact is that this North American theropod lived tens of millions of years before its more famous cousin. It wasn't a tyrannosaur at all, but a type of large theropod known as a carcharodontosaur (and thus closely related to Carcharodontosaurus, and especially close to Neovenator). Until the announcement of Siats in November 2013, the only other known carcharodontosaur from North America was Acrocanthosaurus, itself no slouch in the terrorizing-smaller-dinosaurs department. What makes Siats such big news is, well, how big it was. This theropod measured well over 30 feet from head to tail and weighed in the neighborhood of 4 tons, which would make it the third-largest meat-eating dinosaur from North America after T. rex and Acrocanthosaurus. (In fact, since the type specimen of this dinosaur is a juvenile, we don't know exactly how big Siats would have been fully grown.) Those specs don't place Siats anywhere near the theropod record on other continents—witness the African Spinosaurus and the South American Giganotosaurus—but it was still an impressive meat-eater nonetheless. 69 of 80 Sigilmassasaurus (SIH-jill-MASS-ah-SORE-us), Sijilmassa Lizard This prehistoric scene shows Sigilmassasaurus swallowing a whole fish. Sergey Krasovskiy If you think the last thing the world needs is another dinosaur with an unpronounceable name, rest assured that very few paleontologists accept the validity of Sigilmassasaurus, though this carnivore has still managed to retain its place in the official record books. Discovered in Morocco near the ancient city of Sijilmassa, Sigilmassasaurus (about 30 feet long and 1-2 tons) had a lot in common with the better known and equally multisyllabic Carcharodontosaurus ("great white shark lizard"), of which it was probably a species. However, the possibility does remain that Sigilmassasaurus deserves its genus designation—and that it may not be a carcharodontosaur at all but another undetermined type of large theropod. 70 of 80 Sinosaurus (SIE-no-SORE-us), Chinese Lizard A look at skeletal structure of the head and neck of a Sinosaurus. Ghedoghedo/Wikimedia Commons/CC BY-SA 3.0 Considering how many dinosaurs have been discovered in China, you might think a definitive name like Sinosaurus ("Chinese lizard") would be reserved for a particularly well-attested genus. The fact is, though, that the type fossil of Sinosaurus was discovered in 1948, well before the golden age of Chinese paleontology, and this dinosaur was regarded for the next few decades as a nomen dubium. Then, in 1987, the discovery of a second fossil specimen prompted paleontologists to reclassify Sinosaurus as a species of the North American Dilophosaurus, partly (but not only) because of the paired crests on top of this theropod's head. That was how matters stood until 1993 when the famous Chinese paleontologist Dong Zhiming determined that D.sinensis deserved its own genus—at which point the slightly tainted name Sinosaurus was summoned back into usage. Oddly enough, it turns out that Sinosaurus (about 18 feet long and 1,000 pounds) was related most closely not to Dilophosaurus but to Cryolophosaurus, a contemporary theropod of early Jurassic Antarctica. (By the way, Sinosaurus is one of the few known dinosaurs to have sustained dental trauma: One specimen had a tooth knocked out, presumably in combat, and thus sported a charming, gap-toothed smile.) 71 of 80 Sinraptor (SIN-rap-tore), Chinese Thief This skeleton provides a good look at jaws and teeth of the Sinraptor. FarleyKatz/Wikimedia Commons/CC BY-SA 4.0 The name Sinraptor is misleading in two ways. First, the "sin" part doesn't mean this dinosaur (25 feet long and 1 ton) was evil—it's simply a prefix meaning "Chinese." And second, Sinraptor wasn't a true raptor, a quick, fierce family of carnivorous dinosaurs that didn't arrive on the prehistoric scene until tens of millions of years later. Rather, Sinraptor is believed to have been a primitive allosaur (a type of large theropod) that was ancestral to such giant predators as Carcharodontosaurus and Giganotosaurus. Based on when it lived, paleontologists have concluded that Sinraptor (and other allosaurs like it) preyed on the juveniles of the gigantic sauropods of the late Jurassic period. (The open-and-shut case: Sauropod fossils have been discovered in China bearing the unmistakable imprint of Sinraptor tooth marks.) 72 of 80 Skorpiovenator (SCORE-pee-oh-VEH-nah-tore), Scorpion Hunter Dinosauria-Freak / Wikimedia Commons / Public Domain First things first: The name Skorpiovenator (Greek for "scorpion hunter") has nothing to do with this dinosaur's presumed diet; rather, it's because the sole fossil specimen was surrounded by a bustling colony of living scorpions. Other than its striking name, Skorpiovenator (about 30 feet long and weighing 1 ton) was an average large theropod of the middle Cretaceous period, with a short, blunt skull covered by a weird array of ridges and bumps. This has prompted experts to assign it to the abelisaurs, a sub-family of large theropods (poster genus: Abelisaurus) that were especially common in South America. 73 of 80 Spinosaurus (SPIEN-oh-SOR-us), Spined Lizard ermingut / Getty Images Why did Spinosaurus have a sail? The most likely explanation is that this structure evolved for cooling purposes in the hot Cretaceous climate. It may also have been a sexually selected characteristic—males with bigger sails having more success mating with females. 74 of 80 Spinostropheus (SPY-no-STROH-fee-us), Spined Vertebrae Illustration of a Spinostropheus with mouth open and ready to pounce. Nobu Tamura / Getty Images Spinostropheus (about 12 feet long and 300 pounds) is more interesting for what it reveals about how paleontology works than for how it lived (details of which are rather vague, anyway). For years, this small, two-legged dinosaur of the late Jurrasic period was thought to be a species of Elaphrosaurus, a genus of early theropod closely allied with Ceratosaurus. Then, a further study classified it as an early abelisaur (and thus more closely related to large theropods like Abelisaurus). And upon even further examination, it was classified once more as a close relative of, but distinct genus from, Elaphrosaurus and given its present name. Any questions? 75 of 80 Suchomimus (SOOK-o-MY-mus), Crocodile Mimic Luis Rey/Getty Images The name Suchomimus (Greek for "crocodile mimic") refers to this meat-eating dinosaur's long, toothy, and distinctly crocodilian snout, which it probably used to snap fish out of the rivers and streams of the then-lush Sahara region of northern Africa. 76 of 80 Tarascosaurus ( tah-RASS-coe-SORE-us), Tarasque Lizard ABelov2014 / Wikimedia Commons / CC BY-SA 3.0 Named after the mythological Tarasque, a dragon of medieval French legend, Tarascosaurus is important for being one of the only known abelisaurs (a type of large theropod) to have lived in the northern hemisphere; most abelisaurs were native to South America or Africa. The fossil remains of this 30-foot-long dinosaur are so scattered that some paleontologists don't believe it merits its own genus. Still, this hasn't kept the 2-ton Tarascosaurus from being featured on the Discovery Channel series "Dinosaur Planet," where it was portrayed as an apex predator of late Cretaceous western Europe. Recently, another abelisaur has been discovered in France, the Arcovenator. 77 of 80 Torvosaurus (TORE-vo-SORE-us), Savage Lizard Tim Bewer/Getty Images As is the case with many other large theropods, it isn't yet widely accepted that Torvosaurus (about 35 feet long and 1-2 tons) deserves its own genus. Some paleontologists think this may actually have been a species of Allosaurus or some other existing genus of carnivorous dinosaur. Whatever the case, Torvosaurus was certainly one of the biggest meat-eaters of the late Jurassic period, slightly outweighing the more well-known Allosaurus (if it wasn't actually an Allosaurus itself, of course). Like all the predators of this time, Torvosaurus probably feasted on the babies and juveniles of gigantic sauropods and smaller ornithopods. (Note: This dinosaur shouldn't be confused with the similar-sounding and comparably sized Tarbosaurus, an Asian tyrannosaur that lived tens of millions of years later.) Paleontologists have discovered a new species of Torvosaurus, T. gurneyi, which at over 30 feet from head to tail and weighing more than a ton is the largest identified carnivorous dinosaur of late Jurassic Europe. T. gurneyi wasn't quite as big as its North American equivalent T. tanneri, but it was clearly the apex predator of the Iberian Peninsula. (By the way, the species name gurneyi honors James Gurney, the author and illustrator of the book series "Dinotopia.") 78 of 80 Tyrannotitan (tie-RAN-o-TIE-tan), Giant Tyrant Gastón Cuello/Wikimedia Commons/CC BY-SA 3.0 The partial skeleton of Tyrannotitan was discovered in 2005 in South America, and it continues to be analyzed—some believe that it may not be as giant as first thought. For now, suffice it to say that this appears to have been one of the most dangerous (and most fearsomely named) meat-eating dinosaurs ever to roam the planet. 79 of 80 Xenotarsosaurus (ZEE-no-TAR-so-SORE-us), Strange Tarsus Lizard An artist's rendition of the Xenotarsosaurus that was discovered in rich fossil beds in South America. Sergey Krasovskiy Paleontologists aren't quite sure what to make of Xenotarsosaurus (about 20 feet long and weighing 1 ton), beyond the fact that it was a large theropod dinosaur of late Cretaceous South America. Tentatively, it was classified as an abelisaur. Its stunted arms bear some resemblance to those of the much better known Carnotaurus. However, there's also a case to be made that Xenotarsosaurus was an allosaur rather than an abelisaur, and was thus more closely related to the North American Allosaurus (which lived tens of millions of years earlier). Whatever the case, associated fossil remains imply that Xenotarsosaurus preyed on Secernosaurus, the first hadrosaur ever to be identified in South America. 80 of 80 Yangchuanosaurus (YANG-chwan-oh-SORE-us), Yangchuan Lizard This image of Yangchuanosaurus shows an elaborate, colorful face. Dmitri Bogdanov/Getty Images For all intents and purposes, Yangchuanosaurus filled the same niche in late Jurassic Asia as its fellow large theropod, Allosaurus, did in North America: an apex predator that harassed the numerous sauropods and stegosaurs of its lush ecosystem. The 25-foot-long, 3-ton Yangchuanosaurus possessed an especially long, muscular tail, as well as distinctive ridges and decorations on its face (which were similar to those of a smaller theropod, Ceratosaurus, and may have been brightly colored during mating season). One prominent paleontologist has suggested that Yangchuanosaurus may be the same dinosaur as Metriacanthosaurus but not everyone is convinced.