1 00:00:02,040 --> 00:00:06,760 Speaker 1: Welcome to brain Stuff from How Stuff Works. Hey there, 2 00:00:06,760 --> 00:00:09,479 Speaker 1: brain Stuff lor and vogel bomb here whoever. The human 3 00:00:09,600 --> 00:00:13,000 Speaker 1: stars of the latest Jurassic Park movie are the velociraptors 4 00:00:13,039 --> 00:00:16,520 Speaker 1: are the fan favorite performers. Packs of raptors can gang 5 00:00:16,600 --> 00:00:19,239 Speaker 1: up on anyone or anything, from kids in kitchens to 6 00:00:19,400 --> 00:00:23,800 Speaker 1: a hybridized dino monster. Their attacks are organized, strategic, and 7 00:00:24,000 --> 00:00:26,120 Speaker 1: in most of the movies they rely on a chain 8 00:00:26,160 --> 00:00:29,720 Speaker 1: of command within the group. But is such team oriented 9 00:00:29,720 --> 00:00:32,920 Speaker 1: behavior supported by the fossil record. Before we can answer 10 00:00:32,920 --> 00:00:36,159 Speaker 1: that question, we should clear something up. The dinosaur that's 11 00:00:36,200 --> 00:00:39,400 Speaker 1: called Velociraptor in the Jurassic Park movies and novels was 12 00:00:39,440 --> 00:00:42,760 Speaker 1: based on a completely different animal known as Dano nikus, 13 00:00:43,400 --> 00:00:45,600 Speaker 1: and when it comes to size, there's a huge gap 14 00:00:45,640 --> 00:00:48,960 Speaker 1: between the two. Velociraptor wasn't much bigger than a turkey, 15 00:00:49,159 --> 00:00:51,840 Speaker 1: but the adult Dano nikes measured eleven feet or about 16 00:00:51,840 --> 00:00:54,200 Speaker 1: three point three meters long and may have weighed more 17 00:00:54,240 --> 00:00:59,720 Speaker 1: than two hundred pounds. That's both are classified as dromaeosaurids, 18 00:01:00,200 --> 00:01:03,480 Speaker 1: a family of bird like carnivorous dinosaurs. Members of this 19 00:01:03,520 --> 00:01:07,119 Speaker 1: group had a specialized toe on each foot, which famously 20 00:01:07,360 --> 00:01:10,399 Speaker 1: was held in an upright position while they walked. In theory, 21 00:01:10,640 --> 00:01:13,040 Speaker 1: that habit kept the large hook shaped claws on those 22 00:01:13,080 --> 00:01:16,119 Speaker 1: digits nice and sharp. Historically, it was thought that these 23 00:01:16,120 --> 00:01:19,840 Speaker 1: claws were slashing tools used to disembowel prey, but recent 24 00:01:19,840 --> 00:01:21,840 Speaker 1: studies have found that the claws would have been better 25 00:01:21,840 --> 00:01:25,800 Speaker 1: equipped for stabbing or puncturing Dremeosaurus. Therefore, it might have 26 00:01:25,880 --> 00:01:28,120 Speaker 1: used their remarkable toes to help them cling on to 27 00:01:28,319 --> 00:01:31,080 Speaker 1: large thrashing victims. Think of this as sort of a 28 00:01:31,080 --> 00:01:35,440 Speaker 1: prehistoric rodeo. Getting back to Dana Nikus. This particular dinosaur 29 00:01:35,480 --> 00:01:38,520 Speaker 1: was originally discovered in nineteen thirty one in Montana, but 30 00:01:38,560 --> 00:01:41,399 Speaker 1: it wouldn't be named until nineteen sixty nine. That's when 31 00:01:41,560 --> 00:01:44,959 Speaker 1: Yale paleontologist John Ostrom was overseeing a dig at a 32 00:01:44,959 --> 00:01:47,680 Speaker 1: Montana quarry and the bones of four dino Nikes were 33 00:01:47,680 --> 00:01:50,880 Speaker 1: found strewn around the partial skeleton of a much larger 34 00:01:50,920 --> 00:01:56,120 Speaker 1: herbivore called Tanantosaurus. Late in his career, Ostrom compared this 35 00:01:56,160 --> 00:01:59,720 Speaker 1: paleocrime scene to a wolf pack dispatching its prey. The 36 00:01:59,760 --> 00:02:03,120 Speaker 1: four dead Dino Nikus dinos he theorized had been killed 37 00:02:03,120 --> 00:02:07,200 Speaker 1: while attacking the big plant eater in a coordinated group effort. Later, 38 00:02:07,280 --> 00:02:10,760 Speaker 1: other members of their pack presumably killed that tenacious dinosaur. 39 00:02:11,360 --> 00:02:14,960 Speaker 1: Ostrom's work influenced author Michael Crichton, who wrote pack hunting 40 00:02:15,040 --> 00:02:18,840 Speaker 1: Dromaeosaurus into the first Jurassic Park book. The concept has 41 00:02:18,840 --> 00:02:22,280 Speaker 1: since taken hold of the public's imagination. Moreover, it's had 42 00:02:22,320 --> 00:02:27,000 Speaker 1: a significant impact on dinosaurs science. Therapods, the group containing birds, 43 00:02:27,040 --> 00:02:31,040 Speaker 1: and all known extinct carnivorous dinos, are often found fossilized 44 00:02:31,040 --> 00:02:33,880 Speaker 1: in close proximity to other members of their own species. 45 00:02:34,320 --> 00:02:36,880 Speaker 1: Because of this, it's been argued that plenty of non 46 00:02:36,960 --> 00:02:41,000 Speaker 1: dromosaur predators like Tyrannosaurus and Allosaurus might have hunted in 47 00:02:41,040 --> 00:02:44,680 Speaker 1: packs too, but then again, perhaps they didn't. In a 48 00:02:44,720 --> 00:02:48,440 Speaker 1: two thousand seven paper, paleontologists Bryan Roach and Daniel Brinkman 49 00:02:48,680 --> 00:02:52,080 Speaker 1: dissected the issue at length, and in their opinion, neither 50 00:02:52,160 --> 00:02:55,880 Speaker 1: dana Niicus, nor Velociraptor, nor any other non avian predatory 51 00:02:55,919 --> 00:03:01,080 Speaker 1: dinosaur would have formed packs via email. Brinkman's blamed mammal 52 00:03:01,120 --> 00:03:05,160 Speaker 1: like cooperative pack hunting is an extremely rare and complex behavior, 53 00:03:06,000 --> 00:03:09,880 Speaker 1: so let's talk terminology. Brinkman and Roaches paper defines true 54 00:03:09,960 --> 00:03:13,080 Speaker 1: cooperative pack hunting as a group effort carried out by 55 00:03:13,120 --> 00:03:16,400 Speaker 1: animals that habitually work together with others of their species 56 00:03:16,560 --> 00:03:19,760 Speaker 1: to capture and subdue prey too large for an individual 57 00:03:19,760 --> 00:03:23,760 Speaker 1: predator to kill alone. Furthermore, these team players also defend 58 00:03:23,800 --> 00:03:28,400 Speaker 1: their territory collectively and may share youngster rearing duties. No 59 00:03:28,600 --> 00:03:31,960 Speaker 1: living bird or reptile fits the criteria. It's true that 60 00:03:32,040 --> 00:03:35,680 Speaker 1: nile crocodiles sometimes gang up on big mammals like wilder beasts, 61 00:03:35,680 --> 00:03:38,920 Speaker 1: but they later disperse, and although Harris hawks have been 62 00:03:38,960 --> 00:03:41,480 Speaker 1: known to form hunting parties of up to nine birds, 63 00:03:41,520 --> 00:03:44,840 Speaker 1: they target small game while doing so. That said, there 64 00:03:44,920 --> 00:03:48,120 Speaker 1: is one living animal that, according to Roached Brinkman, might 65 00:03:48,200 --> 00:03:51,600 Speaker 1: offer us some insight into how Drameosaurus and other non 66 00:03:51,640 --> 00:03:55,640 Speaker 1: avian therapods behaved around big prey items, the Komodo dragon. 67 00:03:56,400 --> 00:03:59,360 Speaker 1: Komodo dragons are solo hunters and effective ones at that, 68 00:03:59,800 --> 00:04:02,160 Speaker 1: and adult can bring down victims ten times its own 69 00:04:02,160 --> 00:04:05,840 Speaker 1: body weight. These reptiles are also eager scavengers, and when 70 00:04:05,880 --> 00:04:08,120 Speaker 1: one of them kills a large prey item, others are 71 00:04:08,160 --> 00:04:11,520 Speaker 1: likely to come running. What follows is a gruesome feeding 72 00:04:11,560 --> 00:04:15,200 Speaker 1: frenzy with a dozen or more commodo dragons mobbing the carcass. 73 00:04:15,200 --> 00:04:18,640 Speaker 1: Such meetings get violent fast. While squabbling over a corpse, 74 00:04:18,680 --> 00:04:21,719 Speaker 1: kmmotos may attack one another. Sometimes they even kill and 75 00:04:21,760 --> 00:04:26,000 Speaker 1: eat their smaller competitors at the site. So when paleontologists 76 00:04:26,040 --> 00:04:28,919 Speaker 1: find a large collection of therapod bones and or teeth 77 00:04:28,960 --> 00:04:31,400 Speaker 1: in the same fossil deposit, what should they make of it? 78 00:04:31,600 --> 00:04:34,400 Speaker 1: Should they interpret the remains like a wolf style family unit, 79 00:04:34,720 --> 00:04:36,440 Speaker 1: or should they be viewed as the site of a 80 00:04:36,480 --> 00:04:40,479 Speaker 1: disorganized mob where side squabbles and cannibalism would have been rampant. 81 00:04:41,200 --> 00:04:43,880 Speaker 1: For their part, Brinkman and Roach find the latter scenario 82 00:04:44,000 --> 00:04:47,800 Speaker 1: more probable. Brinkman said Dana Nikus and other non avian 83 00:04:47,839 --> 00:04:51,920 Speaker 1: therapods were most likely solitary hunters who engaged in antagonistic, 84 00:04:52,120 --> 00:04:55,720 Speaker 1: commodo dragon like feeding aggregations, and they interacted with each 85 00:04:55,720 --> 00:04:59,640 Speaker 1: other in ways that were much more contentious, combative, and cannibalistic. 86 00:04:59,800 --> 00:05:04,480 Speaker 1: The has been widely believed. Okay, but what about dinosaur footprints? 87 00:05:04,640 --> 00:05:07,520 Speaker 1: Can they shed any light onto the pack hunting debate. 88 00:05:08,000 --> 00:05:10,679 Speaker 1: In two thousand and seven, a hundred and twenty million 89 00:05:10,760 --> 00:05:14,880 Speaker 1: year old dromosaur trackway was discovered in China, six different 90 00:05:14,880 --> 00:05:17,440 Speaker 1: sets of parallel tracks were found, each made by an 91 00:05:17,440 --> 00:05:20,039 Speaker 1: animal standing about four ft or one point two meters 92 00:05:20,040 --> 00:05:22,520 Speaker 1: tall at the hip, and judging by the nature of 93 00:05:22,560 --> 00:05:24,880 Speaker 1: the sediment, it looks like these prints were all laid 94 00:05:24,920 --> 00:05:28,719 Speaker 1: down within a very short span of time. Anthony J. Martin, 95 00:05:28,880 --> 00:05:33,159 Speaker 1: a leading paleo ichnologist a trace fossil scientist, thinks the 96 00:05:33,160 --> 00:05:36,240 Speaker 1: animals who made them were traveling in some kind of group. 97 00:05:36,720 --> 00:05:40,000 Speaker 1: He said via email. The trackways show these dromayosaurs were 98 00:05:40,000 --> 00:05:43,160 Speaker 1: moving at about the same pace, in the same direction parallel, 99 00:05:43,360 --> 00:05:46,280 Speaker 1: and spaced more or less the same distance apart, so 100 00:05:46,400 --> 00:05:50,320 Speaker 1: I'm fairly certain that this is evidence of group behavior. Still, 101 00:05:50,400 --> 00:05:54,159 Speaker 1: this doesn't necessarily mean the dromosaurs hunted in packs. Maybe 102 00:05:54,160 --> 00:05:56,600 Speaker 1: they were rushing toward a dead body like those independently 103 00:05:56,640 --> 00:06:00,400 Speaker 1: minded komodo dragons. In order to confidently cite any footprint 104 00:06:00,440 --> 00:06:03,760 Speaker 1: assemblage as the product of pack hunting or a similar activity, 105 00:06:04,000 --> 00:06:07,400 Speaker 1: would need, said Martin, more evidence, such as tracks of 106 00:06:07,400 --> 00:06:10,159 Speaker 1: a prey animal that was clearly preceding them and not 107 00:06:10,200 --> 00:06:13,280 Speaker 1: by much time. Best of all would be the drumsur 108 00:06:13,400 --> 00:06:16,720 Speaker 1: tracks ending at a kill site and acknowledgist can dream right. 109 00:06:22,440 --> 00:06:25,120 Speaker 1: Today's episode was written by Mark Mancini and produced by 110 00:06:25,160 --> 00:06:27,760 Speaker 1: Tristan McNeil. For more on this and lots of other 111 00:06:27,880 --> 00:06:31,640 Speaker 1: dynamite topics and dynamite visit our home planet, how Stuff 112 00:06:31,640 --> 00:06:42,560 Speaker 1: Works dot com