New Mexico Museum of Natural History and Science

Jurassic Super Giants Factoids

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Seismosaurus (SIZE-mo-sore-us)

name means "earthquake lizard," in reference to its colossal size
110 feet long, the longest land animal of all time
weighed about 30 tons
a super giant, but a plant eater
lived 150 million years ago during the Jurassic
found by two hikers in 1979 near San Ysidro, Sandoval County, New Mexico
only known from New Mexico
took seven years to collect the huge fossil bones
excavated, prepared, studied and exhibited at the New Mexico Museum of Natural History and Science
nicknames are "Sam","Seismo" and "Stretch"

Saurophaganax (sore-oh-FAG-uh-nax)

name means "reptile eater," in reference to it having been a fierce predator
40 feet long, the largest Jurassic meat eater
weighed about 3 tons
a Jurassic killing machine
lived 150 million years ago during the Jurassic
found by NMMNH volunteers in New Mexico west of Albuquerque
first found in Oklahoma
rare, known from only a few fossil localities
the only New Mexican fossil was excavated, prepared, studied and exhibited at the New Mexico Museum of Natural History and Science
nicknamed "Snax"

Brachiosaurus

Brachiosaurus (BRAK-ee-oh-sore-us)

at 55 tons, the heaviest of all dinosaurs
the bulldog of the brontosaurs, so-called because of its massive forelimbs and thick neck
a plant eater
known from the western United states and from Tanzania in East Africa
once thought to have lived in water, but now known to have walked on land like an elephant

Stegosaurus (STEG-uh-sore-us)

known in New Mexico from fossils found near Grants and Santa Rosa
an "American" dinosaur--all its fossils come from the western United States
a plant eater
some paleontologists still argue about the configuration of the plates on its back--one row or two?