This was the southern limit of Tyrannosaurus. Most Tyrannosaurus skeletons—and certainly the most famous ones—have been found in Montana and South Dakota. Since Alamosaurus bones had already been found at the same site, this cinched the connection between predator and prey.
Unfortunately, dinosaur fossils found in the North Horn are frequently scrappy and brittle. Much remains unknown about the dinosaurs that lived in Utah at the very end of the Cretaceous.
The record of Alamosaurus and Tyrannosaurus in Texas and New Mexico is also quite fragmentary, but, in a press release that accompanied his recent paper about the size of Alamosaurus , paleontologist Denver Fowler mentioned that his team found a tyrannosaur tooth in association with an Alamosaurus vertebra at a New Mexico site. Tyrannosaurus to the north might have been specialists in taking down Edmontosaurus and Triceratops , while their southern cousins had the option of long-necked fare.
Pillar-like legs supported all that tonnage. The late paleontologist Othniel Charles Marsh was amazed by their enormity. In , he described a newfound sauropod from the American west. Imagining the thunderous crash of its footsteps, he named his beast Brontosaurus excelsus , meaning " noble thunder lizard. But the name soon ran into trouble. Helped by dedicated fossil hunters, Marsh was constantly identifying — and naming — creatures from our prehistoric past. Brontosaurus wasn't the first sauropod he named.
Two years earlier, in , Marsh had dubbed another species Apatosaurus ajax. Nowadays, the relationship between these dinosaurs is a bone of contention. Brontosaurus may not be a valid name, but Apatosaurus sure is. You've got to admit that thunder lizard sounds awfully cool. Fewer people get psyched about the name Apatosaurus , which means "deceptive lizard. What was so deceptive about it?
Well, the first Apatosaurus fossils Marsh received were a collection of pelvic and back bones. The latter reminded him of the vertebrae found on extinct marine reptiles called mosasaurs. Yet Marsh still recognized his fossils for the sauropod bones they truly were. It was therefore a resident of the Jurassic. A geologic time period made famous by that Stephen Spielberg movie you might've seen, the Jurassic lasted from Tyrannosaurus rex hadn't evolved yet, but Apatosaurus had to look out for other predators like the foot 8.
Most had hip heights of around From snout to tail, a typical Apatosaurus probably measured somewhere between 72 and 77 feet 22 and One unusually big — but very incomplete — specimen from Oklahoma suggests Apatosaurus could grow even longer, maybe pushing 98 feet 30 meters in total length.
Just remember that this individual was a lot larger than average. Kind of makes you wonder how the Oklahoma giant compared. Western North America was full of other sauropods who brushed shoulders with Apatosaurus. Like Apatosaurus , they were "diplodocids," meaning they had front legs that were shorter than the back pair and long, flexible necks. Apatosaurus was more robust than other diplodocids. To scientists, its weirdest feature is the neck. Thickened by large, downward-facing cervical ribs, Apatosaurus had an extraordinarily wide neck for a sauropod.
Still, Apatosaurus was heavier than the contemporary Diplodocus although much shorter , and about on a par with its other fellow sauropod of late Jurassic North America, Brachiosaurus. Recently, a team of researchers in Colorado discovered the preserved footprints of a herd of Apatosaurus.
The tiniest trackmarks were left by hind but not front feet, conjuring up the image of 5- to pound Apatosaurus hatchlings skittering on their two hind legs to keep up with the thundering herd. If this was really the case, then it's likely that all sauropod babies and young juveniles , and not just those of Apatosaurus, ran bipedally, the better to elude hungry predators like the contemporary Allosaurus.
Like most sauropods, Apatosaurus possessed an extremely long, thin tail that acted as a counterweight to its equally long neck. To judge by the lack of characteristic trackmarks see previous slide that would have been left in the mud by a dragging tail, paleontologists believe Apatosaurus held its long tail off the ground, and it's even possible though far from proven that this sauropod "whipped" its tail at high speeds to intimidate or even inflict flesh wounds on its meat-eating antagonists.
Paleontologists are still debating the posture and physiology of sauropods like Apatosaurus: did this dinosaur hold its neck at its fullest possible height to eat from the high branches of trees which would have entailed its possessing a warm-blooded metabolism, in order to have the energy to pump all those gallons of blood 30 feet into the air , or did it hold its neck parallel to the ground, like the hose of a gigantic vacuum cleaner, feasting on low-lying shrubs and bushes?
The evidence is still inconclusive. Apatosaurus was discovered in the same year as Diplodocus , yet another gigantic sauropod of late Jurassic North America named by Othniel C. These two dinosaurs were closely related, but Apatosaurus was more heavily built, with stockier legs and differently shaped vertebrae. Oddly enough, despite the fact that it was named first, Apatosaurus is today classified as a "diplodocoid" sauropod the other major category are the "brachiosaurid" sauropods, named after the contemporary Brachiosaurus and characterized, among other things, by their longer front than hind legs.
The long neck of Apatosaurus, combined with its unprecedented at the time it was discovered weight, flummoxed 19th-century naturalists. As was the case with Diplodocus and Brachiosaurus, early paleontologists tentatively proposed that Apatosaurus spent most of its time underwater , holding its neck out of the surface like a gigantic snorkel and perhaps looking a bit like the Loch Ness Monster.
It's still possible, though, that Apatosaurus mated in the water, the natural buoyancy of which would have kept males from crushing the females! In , Winsor McCay—best known for his comic strip Little Nemo in Slumberland— premiered Gertie the Dinosaur , a short animated film featuring a realistically hand-drawn Brontosaurus.
Early animation entailed arduously painting individual "cels" by hand; computer animation didn't become widespread until the late 20th century.
Since then, Apatosaurus usually referred to by its more popular name has been featured in countless TV shows and Hollywood movies, with the odd exception of the Jurassic Park franchise and its marked preference for Brachiosaurus. Many paleontologists still lament the demise of Brontosaurus, a name beloved to them since their childhoods.
Robert Bakker , a maverick in the science community, has proposed that Othniel C. Marsh's Brontosaurus merits genus status after all, and doesn't deserve to be lumped in with Apatosaurus; Bakker has since created the genus Eobrontosaurus , which has yet to be widely accepted by his colleagues. However, a more recent study has concluded that Brontosaurus is sufficiently distinct from Apatosaurus to warrant a comeback; watch this space for further details!
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