採样区域 (图. 1) 包括了以下地区: El Mamon,´ T´ıo Gregorio,Corralito and El Hatillo, all north of the town of Urumaco, Falco´n State, northwestern Venezuela. 法尔科州的乌鲁马科镇北部和委内瑞拉的西北部 Specimens were obtained from the middle and upper members of the UrumacoFormation. 化石标本取自于乌鲁马科地表层的中上段。 The middle member of the Urumaco Formation con- sists mostly of claystoneand sand. 乌鲁马科中部的地表层由粘土岩和沙组成。 The grey claystone yields microfossils and the brown claystone containsvertebrate re- mains such as reptiles, 脊椎动物和爬行动物的化石含有灰色黏土岩和褐色粘土岩。 mammals, marine and freshwater fish, as well as coprolites and wood (D´ıaz de Gamero & Linares 1989; Aguilera 2004). 哺乳动物，海洋鱼类和淡水鱼，以及粪化石和木化石（加梅罗&利纳雷斯1989；阿奎莱拉2004） The sandy beds range from shelly sandstones to consolidated coquinalimestone. 沙床的範围从贝壳砂岩到混合贝壳砂岩 In the lower half of this middle member there is an abundant and di-verse marine fish and mollusc fauna in a sandy matrix. 在乌鲁马科中部的地下层有一层琳琅满目的海洋鱼类和软体动物的沙质基质。 The palaeoenvironments are interpreted as inner sublittoral and coastallagoon with riverine and estuarine influence (D´ıaz de Gamero 1996; Aguilera 2004). 古环境将其解释为河口水体浅海内部和泻湖沿岸的影响（加梅罗1996；阿奎莱拉2004）。 The upper member of the Urumaco Formation also comprises grey tobrown, often limey claystones with thin intercalated and locally shellysandstones. 乌鲁马科的地表层还包括灰色的英国粘土岩和棕色的本地砂岩。 The uppermost layer is referred to as the ‘capa de tortugas’ because of its abundantremains of Bairdemys turtles (D´ıaz de Gamero &Linares 1989). 最浅表的一层被称为“卡帕龟群岛”，因为这儿有着数不胜数的贝尔德迈乌龟。（加梅罗&利纳雷斯1989） Several localities and levels have concen- trations of vertebrate fossils. 一些的位置和地层的脊椎动物化石比较集中。 The vertebrate fauna includes marine, estuarine and freshwater fishes,terrestrial, freshwater and marine turtles and crocodilians and terrestrial andaquatic/semiaquatic mammals (Sa´nchez-Villagra et al.2003; Aguilera 2004). 脊椎动物包括海洋、河口和淡水鱼类，淡水和海洋海龟、鳄鱼和陆地和水生或半水栖哺乳动物。（SA´桑切斯比利等。2003；阿奎莱拉2004。） The palaeoenvironments were tropical near- shore marine to low coastalsavannas with freshwater rivers. 海岸附近的古环境是热带海洋性气候与热带稀树草原气候 For additional information about these geological units see Ministerio deEnerg´ıa y Minas (1997). 如果想了解更多地质单元相关信息的话，请看到米呢斯特德恩尔吉雅米纳斯(1997). A complete list of the fossil fauna from the Urumaco Formation has beenrecently summarised in Sa´nchez-Villagra et al.(2003) and Aguilera (2004). 乌鲁马科完整的动物化石群列表最近已在沙县´桑切斯比利（2003）及阿奎莱拉（2004）等地区汇总。 A late Miocene age for the UrumacoFormation is indicated by foraminiferans, while the mammals suggest a SouthAmerican land mammal age between Chasicoan and Huayquerian (D´ıaz de Gamero & Linares 1989), or ap- proximately 9Ma (Marshall & Sempere 1993). 中新世晚期乌鲁马科的地表层有孔虫的迹象，而哺乳动物表明南美洲的陆生哺乳动物时代介于查斯科恩时期和哈奇雷恩时期之间 加梅罗&利纳雷斯1989），或大约9Ma（马歇尔 &森佩雷1993）。 Systematic palaeontology 古生物学 CROCODYLIFORMES (Benton & Clark, 1988) 鳄形动物（本顿&克拉克，1988） ALLIGATORIDAE Gray, 1844 短吻鳄科 格拉伊，1844 PURUSSAURUS Barbosa-Rodrigues, 1892 TYPE SPECIES. Purussaurus brasiliensis Barbosa-Rodrigues1892.普鲁斯鳄巴博萨-罗德里格斯，1892种类型。巴西普鲁斯鳄巴博萨-罗德里格斯1892。 DIAGNOSIS. Giant alligatorids with enlarged and wide skull; 鉴定：巨型短吻鳄头骨宽大 snout tip rounded and ornamented with coarse reticulating ridges andpits; 短吻鳄的鼻子尖圆，且有粗网状隆起和凹坑 long and wide narial aperturesurrounded by a large narial fossa formed by developed rostral canthi thatextend posteriorly to the prefrontal–frontalcontact; 短吻鳄鼻孔的孔径长而宽，宽大的鼻孔由嘴角延伸至的眼角，一直向后延伸至延髓前额叶； oval incisive foramen entirelysurrounded by the premaxillae; 前颌骨将椭圆形的切牙孔完全包围。 nasal and lacrymal bones not in contact; 鼻骨与泪骨不相连；上颞骨空宽大；鳞状骨尾部高而长 large supratemporal fenestra; squamosal high and longposteriorly; nasal and frontal bones separated by the prefrontal bones; 额前骨将鼻骨和额骨分开。 posterior dorsal margin of the skull table (squamosal and supraoccipital)strongly concave.头表骨的后脊（鳞状骨和枕骨）严重弯曲 REMARKS. This genus was erected by Barbosa-Rodrigues (1892), 评论with type species Purussaurus brasiliensis, 根据巴西亚马逊普鲁斯河的一个下颌骨碎片，可以得出这种生物是巴博萨-罗德里格斯（1892），品种为巴西普鲁斯鳄。 on the basis of a fragmented mandible from the Amazon Purus river in Brasil. However, his holotype was subsequently lost 但是这些珍贵的正型标本后来丢失了（Price, 1967）。 Gervais (1876) had earlier described the species Dinosuchus terror basedon a large vertebra collected from the Amazon. 早在1876年，有人根据在亚马逊河发现一些巨大椎骨命名（Gervais,1876）的“恐怖鳄属”（"Dinosuchus"）的属型种“骇人恐怖鳄” Mook (1921) subsequently described a large Colombian alligatorid mandibleas Dinosuchus neivensis and a deformed Amazon symphysis toothed mandible(Langston 1965; Price 1967) 而哥伦比亚发现的一个大型“短吻鳄类”下颌INGEOMINAS, DHL-45，最初被归入“恐怖鳄属”，命名（Mook, 1941）为内华“恐怖鳄”（"Dinosuchus"neivensis），后来改为巴西普鲁斯鳄。as Brachygnathosuchusbraziliensis. Nopcsa (1924), however, recognisedthat the three taxa (Brachygnathosuchus braziliensis, Purussaurus brasili-ensis and Dinosuchus neivensis) were synonymous, keeping Purussaurus as thesenior synonym by date priority. “巴西短颌鳄”（"Brachygnathosuchus braziliensis"Mook, 1921）和“骇人恐怖鳄”（Dinosuchus terror），以及巴西普鲁斯鳄是同一种生物，其中巴西普鲁斯鳄出现的时间最早。 Langston (1965)reviewed the Colombian specimens and concluded thatDinosuchus terror is a nomen vanum and renamed the Colombian species Caimanneivensis. 考古学家把哥伦比亚标本莱斯顿（1965）进行了複审,并指出“骇人恐怖鳄”更名为哥伦比亚凯门鳄。 Patterson (1936, 1943) recognised Purussaurus as a synonym of Caiman. 根据标本帕特森（1936，1943）可以确定普鲁斯鳄就是凯门鳄。 More recently, Bocquentin-Villanueva et al. (1989) compared an additionalskull and associated mandible from the Urumaco Formation (Venezuela) 近来，考古学家将乌鲁马科地层Bocquentin-Villanueva等化石标本的另外一个头骨和相关的下颌骨作比较。 and the Solimo˜es Formation (Brasil) andreerected the genus Purussaurus with the two species P. brasiliensis Barbosa-Rodrigues, 1892 and P. neivensis (Mook, 1941). 巴西亚马逊河流 Solimo˜es地层的化石标本重建了普鲁斯鳄巴博萨-罗德里格斯和“骇人恐怖鳄”的联繫。 Purussaurus mirandai sp. nov. (Figs 2–4,7 A-C)
化石
1989 Purussaurus sp.Bocquentin-Villanueva et al.: 427–438, figs 1, 2. 2003 Purussaurus sp. Sa´nchez-Villagra et al.: 15. 2004 Purussaurus sp. Aguilera: 90–92. ETYMOLOGY. After Francisco de Miranda, from whom the University in Corois named, in recognition of his historical contributions to the HispanoAmerican independence. 词源 之后，为了纪念他在西班牙裔美国人的独立中做出的历史贡献，人们将克罗的大学命名为弗朗西斯科德米兰。 TYPE SPECIMENS. Holotype:UNEFM-CIAAP-1369, a com- plete skull with associated mandibles, 标本类型 正模标本：UNEFM-CIAAP-1369， J. Bocquentin Villanueva在埃尔阿蒂约收集了完整的头骨和下颌骨，股骨和坐骨。 femur and is- chium, collected in 1987 by J. Bocquentin-Villanueva at El Hatillo. Paratypes: AMU-CURS-135 (a skull with associ- ated mandibles), ElHatillo; MCC URU-115-72V (premax- illa and maxilla), El Picache; MCCURU-157-72V (dentary), T´ıo Gregorio; UNEFM-CIAAP-1445,(right mandible), El Hatillo. 副模标本：AMU-CURS-135 （头骨和下颌骨），ElHatillo; MCC URU-115-72V （前颌骨和上颌骨），El Picache; MCCURU-157-72V （ [脊椎] 齿骨），T´ıo Gregorio; UNEFM-CIAAP-1445, (右颌骨), El Hatillo. OTHER MATERIAL EXAMINED. 其他标本的研究 AMU-CURS-33 (isolated posteriortooth), AMU-CURS-33（独立的后牙） T´ıo Gregorio; AMU-CURS-57 (mand ible), T´ıo Gregorio; AMU-CURS-57 (下颌骨), T´ıo Gregorio; MCC URU-76-72V (mandible), T´ıo Gregorio; MCC URU-76-72V (下颌骨), 0.5 km north of quebrada El Picache and 50 m east of Chiguaje fault;UNEFM-CIAAP-1363 (pubis), UNEFM-CIAAP-1367 uebrada El Picache 以北0.5km，Chiguaje断层以东50m.UNEFM-CIAAP-1363(耻骨)UNEFM-CIAAP-1367 quebrada El Picache and 50 m east of Chiguaje fault; UNEFM-CIAAP-1363(pubis), UNEFM-CIAAP-1367 (scapula, coracoid and ilium), UNEFM-CIAAP-1370 (humerus), El Hatillo. (肩胛骨, 喙骨和髂骨),UNEFM-CIAAP-1370 (肱骨), El Hatillo. OCCURRENCE. All specimens come from the upper Miocene Urumaco Formation,Falco´n State, northwestern Venezuela. 发现 所有标本来自第三纪中新世委内瑞拉西北部，法尔科州的乌鲁马科地层。 DIAGNOSIS. Skull large, elongatedand much flatter than in P. brasiliensis and P. neivensis. 鉴定 头骨大而延长，普鲁斯鳄的头骨比短吻鳄和凯门鳄更平坦 Snout with an elongated median depression, wider than in P. brasiliensisand P. neivensis, 普鲁斯鳄的鼻子长且中间凹陷，鼻部也比短吻鳄和凯门鳄更宽 and with very large narial opening, almost 60% of rostrallength. 鼻孔张开得非常大，是普鲁斯鳄嘴部长度的百分之六十。 Premaxilla and maxilla suture extend posteriorly onthe ventral skull surface, 前颌骨和上颌骨缝合线向后延伸至腹侧颅骨表面 with premaxillary bones extending posteriorly to the fourth maxillaryalveolus, 与前颌骨后方延伸到上颌骨的第四个小孔 while the inverted ‘V’ sutureshape on the palatal face reaches the fifth maxillary tooth level. 而该化石标本呈倒“V”形，上颚骨缝合线的交汇处有五颗上颌齿。 On the dorsal skull surface, premaxillae extend up to the lateral marginsof the narial depression. 在背侧颅骨表面，前颌骨延长到鼻孔的外沿的凹陷处。 Premaxillae bear a large incisive foramen thatextends anteriorly between the occlusive fossae for the first mandibular teeth,not so further前颌骨承受较大的切牙孔，刚好向前延伸至第一个下颌牙咬合的凹槽之间。
米兰达UNEFM-CIAAP 1369的头骨最大长度1260mm，巴西的UFAC 1403头骨最大长度1400mm，米兰达比巴西短了140mm，而吻部长度是巴西910mm，米兰达770mm，因此巴西多出来的是上颌骨和吻部(大鼻子)，当然米兰达这个个体头骨比巴西细很多, 685 vs 820mm, (巴西这个个体算是一个比较粗的，1400mm对应820mm宽度, UFAC的头骨上限长度接近，宽度只有765~800mm). MCNC-URU-158-72V是头骨根据右侧的腹面图，保守估测是巴西最大个体DGM R 572(按840mm宽度)计算，比例是690mm vs 718.5mm, 巴西略宽. 对齐上颌骨之后，巴西只是前上颌骨长了75mm，米兰达头骨按照比例(1540-75)*(690/718.5)=1406, 如果巴西按820mm宽度计算，则是701mm，米兰达头骨长度是1442mm 下颌骨，对其第5颗牙之后发现，两者5~14颗保留位置的齿床长度相等，同样位置的宽度是560mm vs 570mm。，下颌骨因为凸出的D1牙槽而长了3cm，其余基本相等。
