Although it wasn’t the largest theropod of the Mesozoic Era – that honor, as stated previously, belongs to the African Spinosaurus–Giganotosaurus takes the crown as the largest meat-eating dinosaur of Cretaceous South America. (Fittingly enough, its presumed prey Argentinosaurus holds the title of “largest South American titanosaur.”) South America, by the way, is where the very first dinosaurs evolved way back during the middle Triassic period, about 230 million years ago.
Giganotosaurus Preceded T. Rex by 30 Million Years
Giganotosaurus prowled the plains and woodlands of South America about 95 million years ago, a whopping 30 million years before its more famous relative, Tyrannosaurus Rex, reared its head in North America. Oddly enough, though, Giganotosaurus was a near-contemporary of the biggest known meat-eating dinosaur, Spinosaurus. Why were the meat-eating dinosaurs of the late Cretaceous period comparatively petite compared to their middle Cretaceous forebears?
No one knows, but it may have had something to do with climate or the relative availability of prey.
||Early Cenomanian stage of the Late Cretaceous Period (97 million years ago)
||Upper Cretaceous Period (67 to 65.5 million years ago)
||12 – 15 m (40-46 feet)
||12-15 m ( 40-50 feet)
||Biped; walked on two large, powerful back legs; fairly agile; could travel up to 31 mph.
||Bipedal, walked upright; powerful tail allowed it to move quickly; could run up to 45 mph.
||Carnivorous; preyed on herbivore dinosaurs
||Carnivorous; preyed on herbivorous dinosaurs, other T. Rex, scavenge
||The name Giganotosaurus means “giant southern lizard” from Greek gigas (γίγας) meaning “giant”, notos (νότος) meaning “southern” and -sauros (-σαύρος) meaning “lizard”.
||The name “Tyrannosaurus” means “tyrant lizard”, from Greek ”tyrannos” (τύραννος) meaning “tyrant, ” and sauros (σαῦρος) meaning “lizard”.
||Western North America, present Mongolia
||July 1993 discovery – first skeleton 70% complete.
||Partial skeleton found in 1902. More than 30 partial Tyrannosaurus specimens have been found since. Over 30 specimens exist.
||7 m (23 feet)
||4-7 m (15-23 feet)
||Giganotosaurus (“giant southern lizard”) is a genus of carcharodontosaurid dinosaur.
||Tyrannosaurus ( “tyrant lizard”) is a genus of coelurosaurian theropod dinosaur.
||Larger than most adult humans; relatively small brain; long skull; back of the skull had a steep forward incline.
||Massive, thick skull; mouth full of serrated teeth .
||Sharp, 8-inch teeth; short, narrow with serrated edges
||Serrated, conical, continually replaced
||2 short, powerful arms with sharp claws on the end of its three-fingered “hands”.
||2 puny arms, couldn’t reach its mouth, two-fingered “hands”.
||Thin, pointed tail
||Powerful, pointed tail