1 00:00:01,920 --> 00:00:07,000 Speaker 1: Welcome to brain Stuff production of iHeart Radio, Hey brain Stuff, 2 00:00:07,040 --> 00:00:11,240 Speaker 1: Lauren Vogelbaum. Here between about a hundred and fifty seven 3 00:00:11,280 --> 00:00:14,840 Speaker 1: and a hundred forty five million years ago, Alasaurus, a 4 00:00:14,960 --> 00:00:19,360 Speaker 1: large predatory dinosaur, stopped what's now North America and Europe. 5 00:00:20,400 --> 00:00:23,599 Speaker 1: The fossil record suggests that the beast was pretty common 6 00:00:24,000 --> 00:00:27,960 Speaker 1: and did we mention it was big. Full grown Allosaurus 7 00:00:27,960 --> 00:00:30,280 Speaker 1: could grow to be thirty four ft or ten and 8 00:00:30,280 --> 00:00:33,560 Speaker 1: a half meters long, nine ft or three meters tall 9 00:00:33,640 --> 00:00:37,720 Speaker 1: at the hip, and way around three point two tons. 10 00:00:37,720 --> 00:00:41,400 Speaker 1: Sherlock Holmes creators or Arthur Conan Doyle mentioned the Alosaurus 11 00:00:41,440 --> 00:00:44,160 Speaker 1: by name in his nineteen twelve science fiction adventure novel 12 00:00:44,240 --> 00:00:48,960 Speaker 1: The Lost World. Yet, even giant carnivores take their lumps. 13 00:00:49,040 --> 00:00:53,280 Speaker 1: From time to time, Ladies and gents, meet Big Al. 14 00:00:54,600 --> 00:00:58,280 Speaker 1: A sub adult Alasaurus with a killer nickname big Ol 15 00:00:58,400 --> 00:01:02,320 Speaker 1: lived in what's now North sun Troll, Wyoming. Scientists would 16 00:01:02,320 --> 00:01:08,280 Speaker 1: eventually recover of his or maybe her or skeleton. Look 17 00:01:08,360 --> 00:01:11,160 Speaker 1: closely at the remains and you'll find no fewer than 18 00:01:11,280 --> 00:01:16,399 Speaker 1: nineteen separate bone fractures, and somehow al sustained injuries to 19 00:01:16,600 --> 00:01:20,880 Speaker 1: multiple backbones. Towbones and ribs. There's also evidence of a 20 00:01:20,959 --> 00:01:25,040 Speaker 1: serious infection on the right foot. Big Owl was unearthed 21 00:01:25,040 --> 00:01:29,679 Speaker 1: at a Wyoming quarry. In five years later, fossil hunters 22 00:01:29,720 --> 00:01:32,800 Speaker 1: working in the same state found another Allosaurus skeleton that's 23 00:01:32,800 --> 00:01:35,920 Speaker 1: come to be known as big Al two, and just 24 00:01:36,080 --> 00:01:39,920 Speaker 1: like its predecessor, this specimen was pretty banged up. Many 25 00:01:39,959 --> 00:01:43,360 Speaker 1: of its bones have been fractured or otherwise damaged, only 26 00:01:43,400 --> 00:01:47,240 Speaker 1: to be re healed during the dinosaur's lifetime, although one 27 00:01:47,319 --> 00:01:50,320 Speaker 1: hip injury apparently never healed over and may have been 28 00:01:50,320 --> 00:01:54,400 Speaker 1: implicated in the ultimate demise of Big Al two. Other 29 00:01:54,480 --> 00:01:58,320 Speaker 1: Alosaurus fossils also bear the telltale signs of serious wounds. 30 00:01:59,000 --> 00:02:01,880 Speaker 1: To fully appreciate eate these, we beat take a step 31 00:02:01,920 --> 00:02:06,520 Speaker 1: back and consider the animals role in its environment. Allosaurus 32 00:02:06,640 --> 00:02:10,840 Speaker 1: lived during the Late Jurassic period. Back then, giant herbivore 33 00:02:10,880 --> 00:02:15,200 Speaker 1: dinosaurs called sauropods thundered across the planet, but we often 34 00:02:15,240 --> 00:02:20,160 Speaker 1: find their bones in close association with Alosaurus materials. At 35 00:02:20,320 --> 00:02:25,080 Speaker 1: Dinosaur National Monument, which straddles the Utah Colorado border, there's 36 00:02:25,120 --> 00:02:28,200 Speaker 1: a protected quarry where visitors can look at a jumbled 37 00:02:28,240 --> 00:02:31,040 Speaker 1: collection of fossils that's been lying together for the past 38 00:02:31,040 --> 00:02:35,760 Speaker 1: a hundred and forty nine million years. Besides Allosaurus remains, 39 00:02:35,760 --> 00:02:39,040 Speaker 1: this quarry includes the bones of such long necked sauropods 40 00:02:39,080 --> 00:02:44,240 Speaker 1: as Diplodocus, Camarasaurus, and a Patosaurus. Fossils belonging to the 41 00:02:44,320 --> 00:02:49,640 Speaker 1: unrelated spiky tailed plant eater Steatosaurus are also present. These 42 00:02:49,680 --> 00:02:53,560 Speaker 1: were just some of the vegetarian dinos that Allosaurus interacted with, 43 00:02:54,320 --> 00:02:57,520 Speaker 1: and there was competition at the buffet line. One of 44 00:02:57,520 --> 00:03:00,880 Speaker 1: its rival predators in late Jurassic North Amera Rica was 45 00:03:00,919 --> 00:03:04,560 Speaker 1: the Seratosaurus, a horn nosed carnivore that could grow over 46 00:03:04,639 --> 00:03:07,920 Speaker 1: nineteen feet or six meters long, and which had a 47 00:03:07,919 --> 00:03:10,880 Speaker 1: short cameo in the movie Jurassic Park three from two 48 00:03:10,880 --> 00:03:16,000 Speaker 1: thousand one. Compared to some other dinosaurs, Alisaurus had a 49 00:03:16,000 --> 00:03:19,480 Speaker 1: weak bite force. The bite of a Tyrannosaurus rex, the 50 00:03:19,600 --> 00:03:22,560 Speaker 1: famous carnivore that evolved tens of millions of years after 51 00:03:22,600 --> 00:03:26,440 Speaker 1: the last Allosaurus died out, may have been four times stronger. 52 00:03:27,919 --> 00:03:32,880 Speaker 1: Even so, Allosaurus performed well under pressure. Mathematical models show 53 00:03:33,000 --> 00:03:35,960 Speaker 1: that the beast's head could withstand lots of physical strain. 54 00:03:37,320 --> 00:03:42,320 Speaker 1: In Paleontologists used computer simulations to learn more about how 55 00:03:42,320 --> 00:03:47,000 Speaker 1: this dinosaur dismembered its prey. According to their research, Allosaurus 56 00:03:47,160 --> 00:03:50,680 Speaker 1: may have sometimes behaved like an overgrown falcon at dinner. 57 00:03:51,760 --> 00:03:55,400 Speaker 1: The animals skull was light and its nick muscles were peculiar, 58 00:03:56,040 --> 00:03:59,520 Speaker 1: but with their simulations, the researchers showed Alasaurus would have 59 00:03:59,520 --> 00:04:02,960 Speaker 1: had an see time plucking meat off of corpses by 60 00:04:03,000 --> 00:04:05,240 Speaker 1: grabbing a hunk of flesh and its jaws and then 61 00:04:05,320 --> 00:04:09,560 Speaker 1: yanking its head backwards. The falcons do the same thing today, 62 00:04:10,320 --> 00:04:14,200 Speaker 1: but while those hunting birds have flight ready wings, Alasaurus 63 00:04:14,240 --> 00:04:18,080 Speaker 1: had clawed hands. Noting their size and range of motion, 64 00:04:18,480 --> 00:04:21,919 Speaker 1: dinosaur expert Kenneth Carpenter wrote in two thousand two that 65 00:04:22,000 --> 00:04:26,000 Speaker 1: Allosaurus could use its arms to quote grasp moderately large 66 00:04:26,040 --> 00:04:30,960 Speaker 1: prey and pull it towards the body. So what counted 67 00:04:31,000 --> 00:04:35,400 Speaker 1: as moderately large prey for a ravenous Alasaurus Maybe beaked 68 00:04:35,400 --> 00:04:39,599 Speaker 1: herbivores like the twenty three ft or seven meter Compotosaurus 69 00:04:39,680 --> 00:04:44,520 Speaker 1: fit the bill, or perhaps juvenile sauropods. If Alosaurus hunted 70 00:04:44,520 --> 00:04:49,400 Speaker 1: adults auropods, scientists aren't sure how. Some species alive in 71 00:04:49,440 --> 00:04:52,279 Speaker 1: the late Jurassic were around twenty four to thirty four 72 00:04:52,320 --> 00:04:56,120 Speaker 1: times heavier than even the biggest allosaurus, so the predators 73 00:04:56,240 --> 00:04:59,760 Speaker 1: might not have bothered A few experts think Alasaurus only 74 00:05:00,000 --> 00:05:04,400 Speaker 1: targeted young, sick, or dead sauropods, leaving healthy grown ups alone. 75 00:05:05,680 --> 00:05:08,480 Speaker 1: On the other hand, it's possible that the dinosaur used 76 00:05:08,480 --> 00:05:11,240 Speaker 1: its serrated teeth to rip the flesh off of giant, 77 00:05:11,360 --> 00:05:15,679 Speaker 1: still living sauropods in non fatal attacks. There's a pretty 78 00:05:15,720 --> 00:05:21,120 Speaker 1: awesome name for this hypothetical feeding technique, flesh grazing. A 79 00:05:21,240 --> 00:05:24,039 Speaker 1: bite marks tell Us. Stegosaurus, for one, was on the 80 00:05:24,040 --> 00:05:28,839 Speaker 1: menu only sometimes, though attacking and armored dinosaur might not 81 00:05:28,960 --> 00:05:33,279 Speaker 1: have been the brightest IDEA one Alosaurus pubic bone shows 82 00:05:33,360 --> 00:05:36,240 Speaker 1: a gaping wound that matches the size and shape of 83 00:05:36,240 --> 00:05:42,480 Speaker 1: a Stegosaurus tail spike. Alosaurus has also been suspected of cannibalism. 84 00:05:42,520 --> 00:05:46,200 Speaker 1: A survey that was published in May looked at two thousand, 85 00:05:46,320 --> 00:05:49,040 Speaker 1: three hundred and sixty eight fossil bones, all were covered 86 00:05:49,080 --> 00:05:54,040 Speaker 1: at the same Jurrassic quarry in Colorado, almost tent bore 87 00:05:54,080 --> 00:05:57,200 Speaker 1: the bite marks of meat eating dinosaurs with serrated teeth. 88 00:05:58,400 --> 00:06:01,400 Speaker 1: Many of these not on bones belonged to sauropods and 89 00:06:01,520 --> 00:06:07,240 Speaker 1: other herbivores. However, some of them came from Alasaurus. Since 90 00:06:07,279 --> 00:06:10,760 Speaker 1: Alasaurus is also the most abundant predatory dinosaur found at 91 00:06:10,760 --> 00:06:13,880 Speaker 1: this dig site, it's entirely possible that we're looking at 92 00:06:13,880 --> 00:06:19,720 Speaker 1: evidence of cannibalistic behavior. Also, no discussion about Allosaurus would 93 00:06:19,720 --> 00:06:24,240 Speaker 1: be complete without mentioning Utah's mysterious Cleveland Lloyd Dinosaur Quarry 94 00:06:24,520 --> 00:06:28,200 Speaker 1: or c l d Q. Fossils of ten different dinos 95 00:06:28,200 --> 00:06:32,400 Speaker 1: species have been excavated here, including plant eaters like Stegosaurus 96 00:06:32,440 --> 00:06:36,520 Speaker 1: and a Patosaurus. Yet a remarkable sixty percent of all 97 00:06:36,520 --> 00:06:39,520 Speaker 1: the dinosaur bones found in the quarry were left behind 98 00:06:39,680 --> 00:06:44,440 Speaker 1: by Allosaurus. Altogether, the quarry has yielded parts of at 99 00:06:44,520 --> 00:06:48,920 Speaker 1: least forty six Allosaurus skeletons. Some were juveniles, others were 100 00:06:48,920 --> 00:06:52,200 Speaker 1: full grown adults, but they all died in the same spot. 101 00:06:52,720 --> 00:06:56,560 Speaker 1: And the question is why and why are the numbers 102 00:06:56,600 --> 00:07:02,200 Speaker 1: so skewed? Why is Alosaurus so overrepresented there? Several explanations 103 00:07:02,200 --> 00:07:05,640 Speaker 1: have been put forth over the years. Maybe the c 104 00:07:05,920 --> 00:07:09,640 Speaker 1: l d Q was once a Jurassic predator trap, and 105 00:07:09,720 --> 00:07:12,720 Speaker 1: basically that's a place where herbivores get caught in the 106 00:07:12,760 --> 00:07:16,640 Speaker 1: thick mud or another substance and then attract carnivores who 107 00:07:16,760 --> 00:07:20,920 Speaker 1: die the same way. All those bodies attract even more carnivores, 108 00:07:21,200 --> 00:07:27,200 Speaker 1: with dead and dying predators vastly outnumbering prey species. Critics 109 00:07:27,280 --> 00:07:29,920 Speaker 1: say the rarity of bite marks on the quarries dinosaur 110 00:07:29,960 --> 00:07:35,240 Speaker 1: bones is a strike against this hypothesis, though Another hypothesis 111 00:07:35,360 --> 00:07:37,800 Speaker 1: is that the quarry was the home of a poisoned 112 00:07:37,800 --> 00:07:41,400 Speaker 1: watering hole or a normal one that dried up, leaving 113 00:07:41,400 --> 00:07:45,320 Speaker 1: thirsty dinosaurs to die on its banks, and a third 114 00:07:45,320 --> 00:07:49,440 Speaker 1: proposed scenario blames flooding for the accumulation of the skeletons. 115 00:07:54,840 --> 00:07:57,600 Speaker 1: Today's episode is based on the article Allosaurus was a 116 00:07:57,640 --> 00:08:00,880 Speaker 1: massive flesh grazer and possible cannibal on how stuff works 117 00:08:00,920 --> 00:08:04,320 Speaker 1: dot Com, written by Mark Vancini. Brain Stuff is production 118 00:08:04,320 --> 00:08:06,480 Speaker 1: of by Heart Radio in partnership of how stuff works 119 00:08:06,480 --> 00:08:09,320 Speaker 1: dot Com and is produced by Tyler Klang. Four more 120 00:08:09,360 --> 00:08:12,040 Speaker 1: podcasts my heart Radio, visit the i heart Radio app, 121 00:08:12,200 --> 00:08:14,920 Speaker 1: Apple Podcasts, or wherever you listen to your favorite show.