1 00:00:00,000 --> 00:00:03,000 可以請各位舉手 2 00:00:03,000 --> 00:00:05,000 或是鼓掌 3 00:00:05,000 --> 00:00:08,000 讓我知道各位的年齡嗎? 4 00:00:08,000 --> 00:00:10,000 我想知道在座有多少人 5 00:00:10,000 --> 00:00:12,000 年齡在3到12歲? 6 00:00:12,000 --> 00:00:16,000 (笑聲) 7 00:00:16,000 --> 00:00:19,000 一個也沒有 嗯? 8 00:00:19,000 --> 00:00:21,000 好吧 9 00:00:21,000 --> 00:00:23,000 今天我的主題是恐龍 10 00:00:23,000 --> 00:00:26,000 各位還記得恐龍嗎? 你們3到12歲時很愛的? 11 00:00:26,000 --> 00:00:31,000 (掌聲) 12 00:00:33,000 --> 00:00:36,000 話說恐龍還蠻搞笑的 13 00:00:36,000 --> 00:00:38,000 (笑聲) 14 00:00:38,000 --> 00:00:40,000 今天我切入的角度會不太一樣 15 00:00:40,000 --> 00:00:43,000 希望各位已經感覺到了 16 00:00:43,000 --> 00:00:45,000 那我就開門見山地講明主旨了 17 00:00:45,000 --> 00:00:47,000 請不要滅絕 18 00:00:47,000 --> 00:00:49,000 (笑聲) 19 00:00:49,000 --> 00:00:51,000 完了 20 00:00:51,000 --> 00:00:55,000 (笑聲) 21 00:00:55,000 --> 00:00:57,000 人們常常問我 22 00:00:57,000 --> 00:01:00,000 事實上 我最常遇到的問題是 23 00:01:00,000 --> 00:01:04,000 爲什麽孩子們這麼喜歡恐龍? 24 00:01:04,000 --> 00:01:06,000 恐龍的魅力在哪? 25 00:01:06,000 --> 00:01:09,000 我通常只會說: 26 00:01:09,000 --> 00:01:11,000 「呃 恐龍很大隻 27 00:01:11,000 --> 00:01:14,000 很特別、而且已經消失了」 28 00:01:14,000 --> 00:01:16,000 全部消失了 29 00:01:16,000 --> 00:01:18,000 嗯,也不盡然如此 30 00:01:18,000 --> 00:01:20,000 但我們等一下再來講這個 31 00:01:20,000 --> 00:01:23,000 所以重點差不多就是這樣 32 00:01:23,000 --> 00:01:27,000 大隻、特別、消失了 33 00:01:27,000 --> 00:01:29,000 我演講的題目是: 34 00:01:29,000 --> 00:01:31,000 變形的恐龍 35 00:01:31,000 --> 00:01:33,000 過早滅絕的原因 36 00:01:33,000 --> 00:01:36,000 現在我假設各位都記得恐龍 37 00:01:36,000 --> 00:01:39,000 恐龍有各種體型 38 00:01:39,000 --> 00:01:42,000 許多種類 39 00:01:42,000 --> 00:01:44,000 很久以前 40 00:01:44,000 --> 00:01:46,000 1900年代早期時 41 00:01:46,000 --> 00:01:49,000 博物館競相尋找恐龍 42 00:01:49,000 --> 00:01:52,000 他們四處尋找、搜集恐龍 43 00:01:52,000 --> 00:01:54,000 整件事情的發展非常有趣 44 00:01:54,000 --> 00:01:57,000 每個博物館都想要更大、更好的恐龍 45 00:01:57,000 --> 00:01:59,000 把其他博物館比下去 46 00:01:59,000 --> 00:02:02,000 所以如果多倫多的博物館 47 00:02:02,000 --> 00:02:05,000 蒐集到一副暴龍的骸骨,大隻的暴龍 48 00:02:05,000 --> 00:02:08,000 那麼渥太華的博物館就想要一隻更大 49 00:02:08,000 --> 00:02:10,000 更好的暴龍 50 00:02:10,000 --> 00:02:12,000 所有的博物館都打一樣的算盤 51 00:02:12,000 --> 00:02:14,000 所以每個博物館都出動 52 00:02:14,000 --> 00:02:17,000 要找更大更好的恐龍骸骨 53 00:02:17,000 --> 00:02:21,000 這是1900年代早期的事 54 00:02:21,000 --> 00:02:24,000 到了大約1970年代 55 00:02:24,000 --> 00:02:26,000 某些科學家聚在一起 56 00:02:26,000 --> 00:02:29,000 開始思索:「搞什麼鬼? 57 00:02:29,000 --> 00:02:31,000 「看看這些恐龍 58 00:02:31,000 --> 00:02:33,000 「全都這麼大隻 59 00:02:33,000 --> 00:02:36,000 「小的恐龍哪去了?」 60 00:02:38,000 --> 00:02:40,000 他們想了又想 61 00:02:40,000 --> 00:02:42,000 甚至還寫論文探討 62 00:02:42,000 --> 00:02:44,000 「小型恐龍在哪兒?」 63 00:02:44,000 --> 00:02:49,000 (笑聲) 64 00:02:52,000 --> 00:02:56,000 去博物館看看吧 65 00:02:56,000 --> 00:02:59,000 看你找不找得到小恐龍 66 00:02:59,000 --> 00:03:02,000 人們假定─其實這樣是有問題的─ 67 00:03:02,000 --> 00:03:04,000 不過人們假定 68 00:03:04,000 --> 00:03:06,000 如果有小型恐龍 69 00:03:06,000 --> 00:03:08,000 如果有年幼的恐龍 70 00:03:08,000 --> 00:03:10,000 很容易就可以認出來 71 00:03:10,000 --> 00:03:12,000 反正就是一隻大隻的 72 00:03:12,000 --> 00:03:15,000 和一隻小隻的 73 00:03:15,000 --> 00:03:18,000 但博物館收藏的都是大型恐龍 74 00:03:18,000 --> 00:03:21,000 這顯示了幾件事 75 00:03:21,000 --> 00:03:25,000 第一:科學家都自視甚高 76 00:03:25,000 --> 00:03:29,000 而且喜歡替恐龍命名 77 00:03:29,000 --> 00:03:31,000 只要能被命名的他們都喜歡 78 00:03:31,000 --> 00:03:34,000 大家都希望有自己命名、專屬於自己的動物 79 00:03:34,000 --> 00:03:37,000 (笑聲) 80 00:03:37,000 --> 00:03:40,000 所以每次他們找到一個看起來不一樣的東西 81 00:03:40,000 --> 00:03:43,000 就會替它取一個不一樣的名字 82 00:03:43,000 --> 00:03:45,000 當然最後就變成 83 00:03:45,000 --> 00:03:48,000 我們有了一大群不同的恐龍 84 00:03:50,000 --> 00:03:53,000 在1975年 85 00:03:53,000 --> 00:03:56,000 某人靈光一閃 86 00:03:56,000 --> 00:03:58,000 就是彼得‧德森 87 00:03:58,000 --> 00:04:00,000 一位賓州大學的博士 88 00:04:00,000 --> 00:04:03,000 發現 89 00:04:03,000 --> 00:04:06,000 恐龍成長的方式 90 00:04:06,000 --> 00:04:08,000 與鳥類有點相似 91 00:04:08,000 --> 00:04:10,000 而鳥類的成長方式 92 00:04:10,000 --> 00:04:12,000 與爬蟲類不同 93 00:04:12,000 --> 00:04:14,000 事實上 94 00:04:14,000 --> 00:04:17,000 他拿食火雞當例子 95 00:04:17,000 --> 00:04:20,000 還蠻酷的。如果你看食火雞 96 00:04:20,000 --> 00:04:23,000 或者其他頭上有冠的鳥類 97 00:04:23,000 --> 00:04:25,000 實際上 98 00:04:25,000 --> 00:04:27,000 牠們在長到成年身型的80%時 99 00:04:27,000 --> 00:04:30,000 頭上的冠才開始生長 100 00:04:30,000 --> 00:04:33,000 各位想想 101 00:04:33,000 --> 00:04:36,000 食火雞基本上長時間保留未成年的特徵 102 00:04:36,000 --> 00:04:39,000 直到個體發生階段的晚期 103 00:04:39,000 --> 00:04:43,000 所以異速頭顱個體發生 104 00:04:43,000 --> 00:04:46,000 就是頭蓋骨的相對生長 105 00:04:46,000 --> 00:04:48,000 所以各位可以看到 106 00:04:48,000 --> 00:04:50,000 如果你發現一隻 107 00:04:50,000 --> 00:04:53,000 只生長發育了80%的動物 108 00:04:53,000 --> 00:04:56,000 但你不知道牠會長成一隻食火雞 109 00:04:56,000 --> 00:04:59,000 你就會以為牠是別的動物 110 00:05:00,000 --> 00:05:03,000 這就是問題所在 111 00:05:03,000 --> 00:05:06,000 彼得‧德森指出了這點 112 00:05:06,000 --> 00:05:08,000 他用的例子是某種鴨嘴恐龍 113 00:05:08,000 --> 00:05:10,000 當時被稱為亞冠龍 114 00:05:10,000 --> 00:05:12,000 他發現 115 00:05:12,000 --> 00:05:15,000 如果你用一隻幼年和一隻成年恐龍 116 00:05:15,000 --> 00:05:18,000 來計算這種恐龍在不同年齡的體型 117 00:05:18,000 --> 00:05:21,000 假設牠是以線性方式生長 118 00:05:21,000 --> 00:05:23,000 牠就會有頭冠 119 00:05:23,000 --> 00:05:26,000 頭冠大小約是成年恐龍的一半 120 00:05:26,000 --> 00:05:28,000 但是實際上未成年的恐龍 121 00:05:28,000 --> 00:05:30,000 只發育了65%的 122 00:05:30,000 --> 00:05:32,000 根本沒有頭冠 123 00:05:32,000 --> 00:05:34,000 所以這就有意思了 124 00:05:34,000 --> 00:05:37,000 這就是 125 00:05:37,000 --> 00:05:40,000 科學家的思路出錯的地方 126 00:05:40,000 --> 00:05:42,000 我是說 如果他們可以接受 127 00:05:42,000 --> 00:05:45,000 接受彼得‧道森的研究結論,然後繼續往下發展 128 00:05:45,000 --> 00:05:47,000 那麼我們的恐龍數目 129 00:05:47,000 --> 00:05:49,000 就會大大減少 130 00:05:49,000 --> 00:05:51,000 但是科學家自視甚高 131 00:05:51,000 --> 00:05:54,000 又喜歡替事物命名 132 00:05:54,000 --> 00:05:57,000 所以他們繼續給恐龍命名 133 00:05:57,000 --> 00:06:00,000 因為牠們看上去不一樣 134 00:06:00,000 --> 00:06:02,000 不過呢,我們有方法可以確實測量 135 00:06:02,000 --> 00:06:05,000 檢查恐龍或任何動物 136 00:06:05,000 --> 00:06:08,000 是年幼的還是較年長的 137 00:06:08,000 --> 00:06:11,000 方法就是真的切骨見髓 138 00:06:11,000 --> 00:06:15,000 但是切開恐龍的骨頭 139 00:06:15,000 --> 00:06:18,000 是很困難的,各位想也知道 140 00:06:18,000 --> 00:06:21,000 因為對博物館而言 141 00:06:21,000 --> 00:06:25,000 恐龍骨頭很珍貴 142 00:06:25,000 --> 00:06:28,000 每個博物館都會非常小心地維護這些骨頭 143 00:06:28,000 --> 00:06:31,000 把骨頭放在小小的發泡容器中 144 00:06:31,000 --> 00:06:34,000 妥善收藏 145 00:06:35,000 --> 00:06:37,000 館方不會樂見你一進來 146 00:06:37,000 --> 00:06:39,000 就打算鋸開骨頭看內部 147 00:06:39,000 --> 00:06:41,000 (笑聲) 148 00:06:41,000 --> 00:06:44,000 所以他們通常不允許你這樣做 149 00:06:44,000 --> 00:06:47,000 但是我有一個博物館 150 00:06:47,000 --> 00:06:49,000 而且我也蒐集恐龍 151 00:06:49,000 --> 00:06:51,000 我可以鋸我自己的收藏 152 00:06:51,000 --> 00:06:53,000 我也這麼做了 153 00:06:53,000 --> 00:06:58,000 (掌聲) 154 00:06:58,000 --> 00:07:03,000 如果你切開小恐龍的骨頭 155 00:07:03,000 --> 00:07:05,000 骨頭裡面疏鬆如海綿 像圖A 156 00:07:05,000 --> 00:07:07,000 如果切開的骨頭是較年長恐龍 157 00:07:07,000 --> 00:07:09,000 裡面十分緊密 158 00:07:09,000 --> 00:07:11,000 一看就知道是成熟的骨頭 159 00:07:11,000 --> 00:07:14,000 所以要區分骨頭是很容易的 160 00:07:14,000 --> 00:07:16,000 現在 161 00:07:16,000 --> 00:07:18,000 讓各位看看這些東西 162 00:07:18,000 --> 00:07:22,000 在北美洲、美國的北美大平原 163 00:07:22,000 --> 00:07:26,000 和加拿大亞伯達省和薩斯喀徹溫省的南部平原上 164 00:07:26,000 --> 00:07:29,000 有一處岩石區被稱為地獄溪地層 165 00:07:29,000 --> 00:07:32,000 從這裡找到了最後存活在地球上的恐龍 166 00:07:32,000 --> 00:07:34,000 其中的12種 167 00:07:34,000 --> 00:07:36,000 是眾所周知的 168 00:07:36,000 --> 00:07:38,000 我指的是12種主要的恐龍 169 00:07:38,000 --> 00:07:40,000 後來都滅絕了 170 00:07:40,000 --> 00:07:43,000 因此我們測試這些恐龍 171 00:07:43,000 --> 00:07:45,000 這差不多就是我一直在從事的工作 172 00:07:45,000 --> 00:07:48,000 我的學生、我的員工 173 00:07:48,000 --> 00:07:51,000 一直在鋸恐龍骨頭 174 00:07:51,000 --> 00:07:53,000 各位一定可以想像 175 00:07:53,000 --> 00:07:55,000 切開腿骨是一回事 176 00:07:55,000 --> 00:07:58,000 但當你走進一間博物館 177 00:07:58,000 --> 00:08:00,000 說:「你們應該不介意 178 00:08:00,000 --> 00:08:03,000 「我切開貴館恐龍的頭骨吧?」 179 00:08:03,000 --> 00:08:06,000 館員會說:「滾開」 180 00:08:06,000 --> 00:08:11,000 (笑聲) 181 00:08:11,000 --> 00:08:15,000 這就是那12種恐龍 182 00:08:15,000 --> 00:08:18,000 我們先看這三種 183 00:08:18,000 --> 00:08:21,000 這些恐龍被稱為腫頭龍 184 00:08:21,000 --> 00:08:23,000 大家都知道 185 00:08:23,000 --> 00:08:25,000 這三種恐龍是親戚 186 00:08:25,000 --> 00:08:27,000 我們假設 187 00:08:27,000 --> 00:08:29,000 牠們的血緣關係 188 00:08:29,000 --> 00:08:32,000 是類似堂兄弟之類的 189 00:08:32,000 --> 00:08:34,000 但沒有人想過 190 00:08:34,000 --> 00:08:37,000 牠們可能有更緊密的關係 191 00:08:37,000 --> 00:08:39,000 換句話說 192 00:08:39,000 --> 00:08:42,000 科學家觀察牠們 看到了不同之處 193 00:08:42,000 --> 00:08:44,000 大家都知道 194 00:08:44,000 --> 00:08:46,000 如果你要確定 195 00:08:46,000 --> 00:08:48,000 你跟你的兄弟姐妹有沒有血緣關係 196 00:08:48,000 --> 00:08:52,000 不能只根據你們的相異之處做判斷 197 00:08:52,000 --> 00:08:54,000 要確認血緣關係 198 00:08:54,000 --> 00:08:56,000 要從相似之處下手 199 00:08:56,000 --> 00:08:58,000 因此人們看著這些恐龍時 200 00:08:58,000 --> 00:09:00,000 總是只注意牠們有多麼不同 201 00:09:00,000 --> 00:09:03,000 腫頭龍的頭上 有一個又大又厚的圓頂 202 00:09:03,000 --> 00:09:06,000 頭部背面有一些小的凸起物 203 00:09:06,000 --> 00:09:10,000 鼻子末端有一堆瘤狀物 204 00:09:10,000 --> 00:09:12,000 這是冥河龍 另一種恐龍 205 00:09:12,000 --> 00:09:16,000 跟腫頭龍生存的時代相同 206 00:09:16,000 --> 00:09:18,000 牠的頭部後面有棘突出 207 00:09:18,000 --> 00:09:20,000 頭上有個很小的圓頂 208 00:09:20,000 --> 00:09:24,000 而且鼻子上也有一堆瘤狀物 209 00:09:24,000 --> 00:09:26,000 然後這隻是名為龍王龍的傢伙 210 00:09:26,000 --> 00:09:28,000 霍格華茲 211 00:09:28,000 --> 00:09:31,000 猜猜牠的名字源自哪裡?龍 212 00:09:31,000 --> 00:09:33,000 這頭恐龍 213 00:09:33,000 --> 00:09:36,000 頭上有棘 沒有圓頂 214 00:09:36,000 --> 00:09:39,000 鼻子上有瘤狀物 215 00:09:39,000 --> 00:09:42,000 沒人注意到這些瘤狀物有點相似 216 00:09:42,000 --> 00:09:44,000 但人們看著這三隻恐龍 217 00:09:44,000 --> 00:09:46,000 心裡想:「這是三種不同的恐龍 218 00:09:46,000 --> 00:09:49,000 「龍王龍也許是其中最原始的 219 00:09:49,000 --> 00:09:52,000 這隻比另一隻更早期一點」 220 00:09:52,000 --> 00:09:55,000 我不是很確定 221 00:09:55,000 --> 00:09:58,000 他們究竟是怎麼挑出這三種恐龍的 222 00:09:58,000 --> 00:10:00,000 但如果你把牠們一字排開 223 00:10:00,000 --> 00:10:03,000 把牠們的頭骨排成一列 224 00:10:03,000 --> 00:10:05,000 排起來會像這樣 225 00:10:05,000 --> 00:10:07,000 龍王龍的最小 226 00:10:07,000 --> 00:10:09,000 冥河龍在中間 227 00:10:09,000 --> 00:10:12,000 腫頭龍是最大的 228 00:10:12,000 --> 00:10:14,000 你們可能認為 229 00:10:14,000 --> 00:10:16,000 這應該很明顯了吧 230 00:10:16,000 --> 00:10:18,000 (笑聲) 231 00:10:18,000 --> 00:10:21,000 但科學家什麼都沒察覺 232 00:10:21,000 --> 00:10:24,000 我們都知道為什麼 233 00:10:24,000 --> 00:10:27,000 因為科學家喜歡替東西命名 234 00:10:27,000 --> 00:10:29,000 所以如果我們 235 00:10:29,000 --> 00:10:31,000 對龍王龍下手 236 00:10:31,000 --> 00:10:33,000 把我們的龍王龍鋸開 237 00:10:33,000 --> 00:10:35,000 你看 骨頭裡面是海綿狀的 238 00:10:35,000 --> 00:10:37,000 非常明顯的海綿 239 00:10:37,000 --> 00:10:39,000 意思是說牠還年幼 240 00:10:39,000 --> 00:10:41,000 而且長得很快 241 00:10:41,000 --> 00:10:43,000 所以牠會長得更大 242 00:10:43,000 --> 00:10:45,000 如果你鋸開冥河龍 243 00:10:45,000 --> 00:10:47,000 也會發現一樣的事情 244 00:10:47,000 --> 00:10:49,000 那個小小的圓頂 245 00:10:49,000 --> 00:10:51,000 長得非常快 246 00:10:51,000 --> 00:10:53,000 迅速地膨脹 247 00:10:53,000 --> 00:10:56,000 有趣的是 龍王龍背上的棘 248 00:10:56,000 --> 00:10:58,000 也長得非常快 249 00:10:58,000 --> 00:11:00,000 冥河龍背上的棘 250 00:11:00,000 --> 00:11:02,000 其實在萎縮 251 00:11:02,000 --> 00:11:04,000 也就是越變越小 252 00:11:04,000 --> 00:11:06,000 而頭上的圓頂則越變越大 253 00:11:06,000 --> 00:11:09,000 如果我們看看腫頭龍 254 00:11:09,000 --> 00:11:12,000 牠頭上有堅硬的圓頂 255 00:11:12,000 --> 00:11:15,000 頭部背面的凸起物 256 00:11:15,000 --> 00:11:17,000 也在萎縮 257 00:11:17,000 --> 00:11:19,000 因此只要看這三種恐龍 258 00:11:19,000 --> 00:11:21,000 科學家很容易就能夠 259 00:11:21,000 --> 00:11:23,000 做出假設 260 00:11:23,000 --> 00:11:25,000 牠們代表不同的成長階段 261 00:11:25,000 --> 00:11:28,000 其實都是同一種動物 262 00:11:28,000 --> 00:11:31,000 當然這就表示 263 00:11:31,000 --> 00:11:35,000 冥河龍和龍王龍 264 00:11:35,000 --> 00:11:37,000 都絕種了 265 00:11:37,000 --> 00:11:42,000 (笑聲) 266 00:11:42,000 --> 00:11:44,000 好吧 267 00:11:46,000 --> 00:11:49,000 當然這就表示 268 00:11:49,000 --> 00:11:53,000 我們有10種主要恐龍要對付 269 00:11:53,000 --> 00:11:55,000 因此我在柏克萊的一位同事 270 00:11:55,000 --> 00:11:58,000 和我一起研究三觭龍 271 00:11:58,000 --> 00:12:00,000 2000年之前 272 00:12:00,000 --> 00:12:02,000 請記住 273 00:12:02,000 --> 00:12:04,000 三觭龍最初是在1800年代發現的 274 00:12:04,000 --> 00:12:07,000 在2000年之前 沒有人看過 275 00:12:07,000 --> 00:12:10,000 幼年的三觭龍 276 00:12:10,000 --> 00:12:13,000 全世界每座博物館都有一隻三觭龍 277 00:12:13,000 --> 00:12:17,000 但不曾有人找到幼年三觭龍過 278 00:12:17,000 --> 00:12:19,000 我們都知道為什麼,對吧? 279 00:12:19,000 --> 00:12:22,000 因為每個人都想要大隻的 280 00:12:22,000 --> 00:12:24,000 所以大家的都是大隻的 281 00:12:24,000 --> 00:12:26,000 我們去考古時找到一大堆東西 282 00:12:26,000 --> 00:12:28,000 一大堆小三觭龍的骸骨 283 00:12:28,000 --> 00:12:32,000 到處都是,遍佈整個區域 284 00:12:32,000 --> 00:12:34,000 因此我們博物館裡有一大堆 285 00:12:34,000 --> 00:12:39,000 (笑聲) 286 00:12:39,000 --> 00:12:41,000 大家都說這是因為我有一座小博物館 287 00:12:41,000 --> 00:12:44,000 當你有小博物館,你就會有小恐龍 288 00:12:44,000 --> 00:12:47,000 (笑聲) 289 00:12:47,000 --> 00:12:49,000 如果各位觀察三觭龍 290 00:12:49,000 --> 00:12:51,000 就會發現牠在改變 變形 291 00:12:51,000 --> 00:12:53,000 當幼年的個體長大時 292 00:12:53,000 --> 00:12:55,000 牠們的角會往後彎 293 00:12:55,000 --> 00:12:57,000 接著越長越大之後 294 00:12:57,000 --> 00:12:59,000 角會再往前彎 295 00:12:59,000 --> 00:13:01,000 還蠻酷的 296 00:13:01,000 --> 00:13:03,000 請各位看看頭骨的邊緣 297 00:13:03,000 --> 00:13:06,000 上面三角狀的小骨頭 298 00:13:06,000 --> 00:13:08,000 會長大變成三角形 299 00:13:08,000 --> 00:13:11,000 然後在邊緣扁下去變平 300 00:13:11,000 --> 00:13:13,000 就像剛剛講過的棘一樣 301 00:13:13,000 --> 00:13:16,000 長在腫頭龍背上的棘 302 00:13:16,000 --> 00:13:20,000 然後因為我有蒐集幼年三觭龍 303 00:13:20,000 --> 00:13:22,000 我就把牠們鋸開 304 00:13:22,000 --> 00:13:24,000 觀察內部 305 00:13:24,000 --> 00:13:27,000 小隻的恐龍骨頭裡面很像海綿 306 00:13:27,000 --> 00:13:30,000 中型的也很像海綿 307 00:13:30,000 --> 00:13:32,000 有趣的是 308 00:13:32,000 --> 00:13:34,000 成年的三觭龍 骨頭內部也像海綿 309 00:13:34,000 --> 00:13:37,000 這副頭蓋骨有兩公尺長 310 00:13:37,000 --> 00:13:40,000 是非常大的頭 311 00:13:40,000 --> 00:13:42,000 但還有另一種恐龍 312 00:13:42,000 --> 00:13:45,000 樣子也長這樣 313 00:13:45,000 --> 00:13:48,000 長得像三觭龍 但是更大隻 314 00:13:48,000 --> 00:13:51,000 叫做牛角龍 315 00:13:51,000 --> 00:13:54,000 當我們把牛角龍切開時 316 00:13:54,000 --> 00:13:56,000 發現牠有成熟的骨頭 317 00:13:56,000 --> 00:13:58,000 不過牠的頭盾上有大洞 318 00:13:58,000 --> 00:14:01,000 大家都說三觭龍和牛角龍 319 00:14:01,000 --> 00:14:03,000 不可能是同一種動物 320 00:14:03,000 --> 00:14:05,000 因為牛角龍比三觭龍大 321 00:14:05,000 --> 00:14:10,000 (笑聲) 322 00:14:10,000 --> 00:14:12,000 頭盾上還有洞 323 00:14:12,000 --> 00:14:15,000 我說:「呃,那我們有幼年的牛角龍嗎?」 324 00:14:15,000 --> 00:14:18,000 他們回答:「嗯,沒有」 325 00:14:18,000 --> 00:14:21,000 「但是牠的頭盾上有洞」 326 00:14:21,000 --> 00:14:24,000 因此我的一位研究生約翰‧史坎納拉 327 00:14:24,000 --> 00:14:26,000 研究了我們所有的蒐藏 328 00:14:26,000 --> 00:14:28,000 赫然發現 329 00:14:28,000 --> 00:14:30,000 這些洞的成形 330 00:14:30,000 --> 00:14:32,000 源自三觭龍 331 00:14:32,000 --> 00:14:35,000 當然在牛角龍頭上已經是完整的洞 332 00:14:35,000 --> 00:14:38,000 所以他發現的恐龍 333 00:14:38,000 --> 00:14:40,000 處於三觭龍和牛角龍之間的過渡時期 334 00:14:40,000 --> 00:14:42,000 還蠻酷的 335 00:14:42,000 --> 00:14:44,000 因此現在我們知道 336 00:14:44,000 --> 00:14:46,000 牛角龍 337 00:14:46,000 --> 00:14:49,000 其實是成年的三觭龍 338 00:14:49,000 --> 00:14:51,000 當我們在替恐龍命名 339 00:14:51,000 --> 00:14:53,000 或任何其他東西命名時 340 00:14:53,000 --> 00:14:55,000 第一個名字都會長存 341 00:14:55,000 --> 00:14:59,000 第二個名字都會被遺忘 342 00:14:59,000 --> 00:15:02,000 因此牛角龍也滅絕了 343 00:15:02,000 --> 00:15:05,000 如果你有看新聞,講到三觭龍時 344 00:15:05,000 --> 00:15:07,000 很多新聞記者根本大錯特錯 345 00:15:07,000 --> 00:15:10,000 他們認為應該保留牛角龍,剔除三觭龍 346 00:15:10,000 --> 00:15:12,000 但這是不可能發生的 347 00:15:12,000 --> 00:15:17,000 (笑聲) 348 00:15:18,000 --> 00:15:21,000 所以說 我們可以對許多恐龍做同樣的事 349 00:15:21,000 --> 00:15:23,000 像是這隻埃德蒙頓龍 350 00:15:23,000 --> 00:15:25,000 和大鴨龍 351 00:15:25,000 --> 00:15:28,000 大鴨龍:巨大的鴨子 352 00:15:28,000 --> 00:15:30,000 是一種大型的鴨嘴龍 353 00:15:30,000 --> 00:15:32,000 牠們是另一個例子 354 00:15:32,000 --> 00:15:34,000 我們以組織學的角度觀察骨頭 355 00:15:34,000 --> 00:15:37,000 骨骼組織學顯示 356 00:15:37,000 --> 00:15:39,000 埃德蒙頓龍是幼年恐龍 357 00:15:39,000 --> 00:15:41,000 或至少是未成年的 358 00:15:41,000 --> 00:15:44,000 另一隻則是成年恐龍 359 00:15:44,000 --> 00:15:47,000 個體發生歷程很完備 360 00:15:47,000 --> 00:15:50,000 因此大鴨龍也不存在了 361 00:15:50,000 --> 00:15:53,000 我們一直重複這個過程 362 00:15:53,000 --> 00:15:55,000 到最後一種恐龍 363 00:15:55,000 --> 00:15:57,000 暴龍 364 00:15:57,000 --> 00:15:59,000 這裡有兩隻恐龍 365 00:15:59,000 --> 00:16:02,000 暴龍和矮暴龍 366 00:16:02,000 --> 00:16:04,000 (笑聲) 367 00:16:04,000 --> 00:16:07,000 又來了,真讓人疑惑 368 00:16:07,000 --> 00:16:10,000 (笑聲) 369 00:16:10,000 --> 00:16:12,000 但科學家問了個好問題 370 00:16:12,000 --> 00:16:14,000 他們觀察這兩隻恐龍 371 00:16:14,000 --> 00:16:17,000 說 小隻有17顆牙 大隻的有12顆牙 372 00:16:17,000 --> 00:16:19,000 這完全沒有道理 373 00:16:19,000 --> 00:16:21,000 因為我們從未發現有哪一種恐龍 374 00:16:21,000 --> 00:16:23,000 年紀越大 牙齒會越多 375 00:16:23,000 --> 00:16:25,000 因此事實擺在眼前 376 00:16:25,000 --> 00:16:28,000 牠們一定不一樣 377 00:16:28,000 --> 00:16:30,000 所以我們鋸開恐龍 378 00:16:30,000 --> 00:16:32,000 果真 379 00:16:32,000 --> 00:16:35,000 矮暴龍的骨頭是幼年的 380 00:16:35,000 --> 00:16:38,000 暴龍的骨頭較成熟 381 00:16:38,000 --> 00:16:41,000 似乎還可以長更大 382 00:16:41,000 --> 00:16:43,000 然後 在我們工作的洛磯山脈博物館 383 00:16:43,000 --> 00:16:45,000 有四隻暴龍 384 00:16:45,000 --> 00:16:47,000 我可以把牠們通通鋸開 385 00:16:47,000 --> 00:16:50,000 但實際上不用這麼做 386 00:16:50,000 --> 00:16:53,000 因為我只要把牠們的下巴排開 387 00:16:53,000 --> 00:16:56,000 就會發現 最大隻的有12顆牙 388 00:16:56,000 --> 00:16:58,000 第二大的有13顆牙 389 00:16:58,000 --> 00:17:00,000 第三大的有14顆牙 390 00:17:00,000 --> 00:17:02,000 當然 矮暴龍有17顆牙 391 00:17:02,000 --> 00:17:05,000 所以我們就去看其他人的蒐藏 392 00:17:05,000 --> 00:17:09,000 發現有一隻恐龍似乎有15顆牙 393 00:17:09,000 --> 00:17:12,000 因此很容易得到結論 394 00:17:12,000 --> 00:17:14,000 就是暴龍的個體發生歷程 395 00:17:14,000 --> 00:17:17,000 包括矮暴龍 396 00:17:17,000 --> 00:17:22,000 因此我們又要跟一種恐龍說拜拜了 397 00:17:22,000 --> 00:17:24,000 (笑聲) 398 00:17:24,000 --> 00:17:28,000 因此 399 00:17:28,000 --> 00:17:30,000 到白堊紀末期 400 00:17:30,000 --> 00:17:33,000 我們只剩七種恐龍 401 00:17:33,000 --> 00:17:36,000 很好的數字 402 00:17:36,000 --> 00:17:39,000 很適合絕種 我覺得啦 403 00:17:39,000 --> 00:17:41,000 各位可以想像 404 00:17:41,000 --> 00:17:44,000 國小四年級生肯定大失所望 405 00:17:44,000 --> 00:17:46,000 小四生很愛恐龍 406 00:17:46,000 --> 00:17:49,000 每一種都如數家珍 407 00:17:51,000 --> 00:17:54,000 聽到這個一定會很沮喪 408 00:17:54,000 --> 00:17:56,000 (笑聲) 409 00:17:56,000 --> 00:17:58,000 謝謝各位 410 00:17:58,000 --> 00:18:01,000 (掌聲)