The Dinosaurs and Prehistoric Animals of Texas

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Which Dinosaurs and Prehistoric Animals Lived in Texas?

Acrocanthosaurus, a dinosaur of Texas. Wikimedia Commons

The geologic history of Texas is as rich and deep as this state is big, running all the way from the Cambrian period to the Pleistocene epoch, an expanse of over 500 million years. (Only dinosaurs dating to the Jurassic period, from about 200 to 150 million years ago, aren't well-represented in the fossil record.) Literally hundreds of dinosaurs and other prehistoric animals have been discovered in the Lone Star State, of which you can explore the most important in the following slides. (See a list of dinosaurs and prehistoric animals discovered in each U.S. state.)

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Paluxysaurus, the official state dinosaur of Texas. Dmitry Bogdanov

In 1997, Texas designated Pleurocoelus as its official state dinosaur. The trouble is, this middle Cretaceous behemoth may well have been the same dinosaur as Astrodon, a similarly proportioned titanosaur that was already the official dinosaur of Maryland, and thus not a fitting representative of the Lone Star State. Attempting to rectify this situation, the Texas legislature recently replaced Pleurocoelus with the extremely similar Paluxysaurus, which--guess what?--may actually have been the same dinosaur as Pleurocoelus, just like Astrodon!

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Acrocanthosaurus, a dinosaur of Texas. Dmitry Bogdanov

Although it was initially discovered in neighboring Oklahoma, Acrocanthosaurus only fully registered in the public imagination after two much more complete specimens were unearthed from the Twin Mountains Formation in Texas. This "tall-spined lizard" was one of the biggest and meanest meat-eating dinosaurs that ever lived, not quite in the same weight class as the roughly contemporary Tyrannosaurus Rex, but still a fearsome predator of the late Cretaceous period.  

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Dimtrodon, a prehistoric reptile discovered in Texas. Wikimedia Commons

The most famous dinosaur that wasn't actually a dinosaur, Dimetrodon was an earlier type of prehistoric reptile known as a pelycosaur, and died out by the end of the Permian period, well before the first dinosaurs arrived on the scene. Dimetrodon's most distinctive feature was its prominent sail, which it probably used to warm up slowly during the day and cool off gradually at night. The type fossil of Dimetrodon was discovered in the late 1870's in the "Red Beds" of Texas, and named by the famous paleontologist Edward Drinker Cope.

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Quetzalcoatlus, a pterosaur discovered in Texas. Nobu Tamura

The biggest pterosaur that ever lived--with a wingspan of 30 to 35 feet, about the size of a small plane--the "type fossil" of Quetzalcoatlus was discovered in Texas' Big Bend National Park in 1971. Because Quetzalcoatlus was so huge and ungainly, there is some controversy as to whether or not this pterosaur was capable of flight, or simply stalked the late Cretaceous landscape like a comparably sized theropod and plucked small, quivering dinosaurs off the ground for lunch.

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Adelobasileus, a prehistoric mammal of Texas. Karen Carr

From the very big, we arrive at the very small. When the tiny, fossilized skull of Adelobasileus (the "obscure king") was unearthed in Texas in the early 1990's, paleontologists thought they had discovered a true missing link: one of the first true mammals of the middle Triassic period to have evolved from therapsid ancestors. Today, the exact position of Adelobasileus on the mammalian family tree is more uncertain, but it's still an impressive notch in the hat of the Lone Star State.

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Alamosaurus, a dinosaur of Texas. Dmitry Bogdanov

A 50-foot-long titanosaur similar to Paluxysaurus (see slide #2), Alamosaurus wasn't named after the famous Alamo of San Antonio, but the Ojo Alamo formation of New Mexico (where this dinosaur was first discovered, though additional fossil specimens hail from the Lone Star State). According to one recent analysis, there may have been as many as 350,000 of these 30-ton herbivores roaming Texas at any given time during the late Cretaceous period!

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Pawpawsaurus, a dinosaur of Texas. Wikimedia Commons

The oddly named Pawpawsaurus--after the Pawpaw Formation in Texas--was a typical nodosaur of the middle Cretaceous period (the nodosaurs were a subfamily of ankylosaurs, the armored dinosaurs, the main difference being that they lacked clubs at the end of their tails). Unusually for an early nodosaur, Pawpawsaurus possessed protective, bony rings over its eyes, making it a tough nut for any meat-eating dinosaur to crack and swallow.

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Texacephale, a dinosaur of Texas. Jura Park

Discovered in Texas in 2010, Texacephale was a pachycephalosaur, a breed of plant-eating, head-butting dinosaurs characterized by their unusually thick skulls. What set Texacephale apart from the pack is that, in addition to its three-inch-thick noggin, it had characteristic creases along the sides of its skull, which probably evolved for the sole purpose of shock absorption. (It wouldn't do much good, evolutionarily speaking, for Texacephale males to drop dead while competing for mates.)

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Various Prehistoric Amphibians

Diplocaulus, a prehistoric amphibian of Texas. Nobu Tamura

They don't get nearly as much attention as the state's giant-sized dinosaurs and pterosaurs, but prehistoric amphibians of all stripes roamed Texas hundreds of millions of years ago, during the Carboniferous and Permian periods. Among the genera calling the Lone Star State home were Eryops, Cardiocephalus and the bizarre Diplocaulus, which possessed an oversized, boomerang-shaped head (which probably helped protect it from being swallowed alive by predators).

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Various Megafauna Mammals

The Columbian Mammoth, a prehistoric animal of Texas. Wikimedia Commons

Texas was every bit as big during the Pleistocene epoch as it is today--and, without any traces of civilization getting in the way, it had all the more room for wildlife. This state was traversed by a wide range of mammalian megafauna, ranging from Woolly Mammoths and American Mastodons to Saber-Toothed Tigers and Dire Wolves. Sadly, all of these animals went extinct shortly after the last Ice Age, succumbing to a combination of climate change and predation by Native Americans.