安徽潜山古新世裂齿目一新属兼论中国古新世裂齿类

记述了安徽潜山盆地古新世裂齿目一新属种 ,命名为潜水本爱兽 (Benaiusqianshuiensisgen .etsp .nov .)。标本产于望虎墩组下段底部 ,为一带犬齿和完整颊齿列的左下颌骨。新种的主要特点是 :个体较小 ,下齿列齿式 2 + ?·1·4·3,i2略有增大 ,p1存在但退化成单根且侧扁 ,p3无下后尖 ,p4次臼齿化且无下内尖 ,下三角座前后压缩且下前尖退化 ,m3三叶。中国曾经记述的和被认为是裂齿类的古新世哺乳动物共有 9个属种 :Lofochaiusbrachyo dus、Meiostylodonzaoshiensis、Anchilestesimpolitus、Dysnoetodonminuta、Interogaledatangensis、Pletho rodonchienshanensis、Huananiusyoungi、Yuesthonyxtingae和Simplodonqianshanensis。经过仔细比较研究它们的齿列 ,作者认为 ,Lofochaius、Meiostylodon、Interogale、Plethorodon和Simplodon可能属于裂齿类 ,而Anchilestes、Dysnoetodon、Huananius和Yuesthonyx则可能与裂齿类没有很近的亲缘关系。广东南雄盆地上湖组Lofochaiusbrachyodus的P1和P2退化、P4有一定程度的臼齿化、外架窄、主尖锥状、前尖棱和后尖棱的颊侧端内收 ,显示了裂齿类的特点。湖南茶陵盆地枣市组Meiostylodonzaoshiensis的i2增大、上臼齿主尖锥状、柱尖和后附尖发育、前尖棱和后尖棱的颊侧?     

甘肃龙担早更新世丽牛下颌骨新材料及其对虎亚科捕食策略的证据——龙担哺乳动物群补充报道之四(英文)

记述了甘肃龙担早更新世哺乳动物群中首次发现的一件丽牛(Leptobos)下颌骨,这是我国目前发现的保存最为完整的丽牛下颌材料。依据p3、p4的下前尖与下前附尖分离,下后尖向后延伸不与下前尖愈合,m1-m3的下后尖和下内尖冠面形状近于圆形,连续发育有下外附尖,m2的下后附尖弱,m2和m3的下原尖和下次尖有前后向收缩等特征,以及相同地点产出的短角丽牛头骨,将新材料归为Leptobos brevicornis。新材料补充了丽牛的下颌形态特征:下颌骨水平支窄长,齿槽间隙对颊齿齿列的比例大,前臼齿列短,水平支与垂直支之间的夹角约为120°,下颌角约呈90°。这件下颌骨的前端保留有食肉动物袭击的痕迹,该伤痕可以被解释为由大型虎亚科动物攻击丽牛时犬齿刺穿形成。这样的骨骼证据表明,攻击猎物口鼻部而使猎物窒息死亡,这种与现生大型猫科动物类似的捕食行为在早更新世的虎亚科动物中已经出现。     

内蒙古二连盆地呼和勃尔和剖面中始新世仓鼠类化石(英文)

描述了产自内蒙古二连盆地呼和勃尔和剖面伊尔丁曼哈组底部砂岩中的3种仓鼠类化石:内蒙古祖仓鼠(新种)Pappocricetodon neimongolensis sp.nov.,中条祖仓鼠(相似种)Pappocricetodon cf.P. zhongtiaensis和祖仓鼠(未定种)Pappocricetodon sp.。P.neimongolensis的特征是有P4或者DP4;M1前附尖细小,前叶小,原尖前棱通常至原小尖横向延伸,再转向前颊侧与前附尖相连,无原尖后棱,原小尖与前尖通过前脊相连;M2原尖后棱较为发育;M3次尖不退化;m1下后尖比下原尖位置靠前;m2下原尖后棱完整,连接下后尖或直达下后尖基部;m3不退化,下外脊S型。新种形态与早期仓鼠类Pappocricetodon antiquus接近,但又略显原始。同时,在该层位还出现有M1前叶已经增大的Pappocricetodon sp.和中脊发育的Pappocricetodon cf.P.zhongtiaensis,表明当时仓鼠类已出现多样化,其起源可能要早于中始新世的伊尔丁曼哈期。     

四川德格上新蹄兔亚科(Pliohyracinae)一新属

以西藏后裂爪蹄兔 (PostschizotheriumtibetensisZongetal.,1 996)为基础 ,建立了上新蹄兔亚科 (PliohyracinaeOsborn ,1 899)一新属 :横断山蹄兔 (Hengduanshanhyraxgen .nov .)。它出现在四川甘孜德格的上上新统汪布顶组中。其主要特征是个体明显比Postschizotherium的小 ,吻部短而宽 ,脸部狭 ,齿隙在门齿之间、1 3和C之间以及在C和P1之间存在 ,颊齿从P1至M3紧密排列 ,上犬齿小、单根和前臼齿化不明显 ,前臼齿稍臼齿化 ,次尖小或不存在 ,P4具中附尖 ,上臼齿呈长方形 ,长大于宽 ,前附尖和中附尖发育 ,以及在臼齿的壁上存在少量的白垩质等等     

食虫类和翼手类化石在内蒙古上始新统首次发现

描述了2种食虫类化石(Anatolechinos neimongolensis gen.et sp.nov.,Ictopidium lechei),1刺猬科(属、种未定)(Erinaceidae gen.et sp.indet.)和2类属、种未定的蝙蝠化石(Microchirop- tera gen.et sp.indet.A和B)。Anatolechinos gen.nov.的主要特点是:个体较小;具pl/1;颊齿齿冠低,主齿尖低钝;P3-M3前附尖低小;P3-M2的后附尖脊短而低,次尖与后齿带有棱相连,舌侧无齿带;P5-4舌叶较长,次尖大;P3次尖与原尖有棱相连;M1原小尖和后小尖的前、后棱均较短,次尖前棱很弱;M3后小尖后棱长;下臼齿下内尖棱短等。认为原归入齿鼩猬的Tupaio- don huadianensis也应归入Anatolechinos新属。新种A.neimongolensis与A.huadianensis的主要区别是其个体较小,齿冠稍高,p4无下前边尖,外齿带弱而不完全等。将Anatolechinos归入Eri- naceidae的Tupaiodontinae。讨论了内蒙古中-西部在晚始新世的古生态环境。     

陕西蓝田晚中新世灞河组松鼠科和林跳鼠科化石

描述了陕西蓝田晚中新世灞河组的松鼠类和林跳鼠类。松鼠科化石包括3个种:骊山花鼠(新种)Eutamias lishanemis sp.nov.,细小岩松鼠(新种)Sciurotamias pusillus sp.nov.和松鼠属(未定种)Sciurus sp.;林跳鼠科有两个种:西安脊仓跳鼠(新种)Lophocricetus xianensis sp.nov.和脊仓跳鼠(未定种)Lophocricetus sp.。在牙齿的形态上,蓝田松鼠科的新种分别与现生花鼠(Eutamias sibiricus)和岩松鼠(Sciurotamias davidianus)很相似,但特征原始。其中Sciurotamias pusillus新种代表了该属最早的地史记录;Lophocricetus xianensis新种比内蒙古最晚中新世常见的葛氏脊仓跳鼠(Lophocricetus grabaui)原始得多,为中国现知较为原始的一种。这些新种的特征如下:骊山花鼠(Eutamias listmnensis):个体比现生花鼠(Eutamias sibiricus)稍大,前臼齿和第三臼齿的尺寸比现生种的相对大。P4具完整的前边脊,明显臼齿化;上臼齿的原尖较收缩,中附尖不发育;M3无后脊;下臼齿的下内尖几乎融汇于后边脊,下中尖很小。细小岩松鼠(Sciurotamias pusillus):岩松鼠属中个体较小的一种,齿尖和齿脊比Sciurota- mias wangi和S.leilaoensis的高且较强壮。P4似三角形,前附尖膨大;M1/2的原尖收缩,时见小的后小尖和中附尖;m1/2的下内尖界限模糊,唇侧谷窄浅;m3明显向后扩展。西安脊仓跳鼠(Lophocricetus xianensts):Lophocricetus属中个体较小的一种,M1和M2具小或脊状的原附尖,m1和m2的外附尖和齿带不甚发育。M1的中尖通常弱,中脊短,内脊连接前尖或原脊,后边脊连接后脊;M2常见双前边脊,中脊伸达齿缘;m1下外脊的后部低、弱甚至断开,下次尖与下内尖或下中尖与下内尖间的脊连接;m2的下原尖连接下后尖或前边脊。脊仓跳鼠是中亚和北亚特有的一属啮齿动物,被认为从异蹶鼠属(Heterosminthus)演化而来,近10余年来有较多的发现和研究。本文特别对其系统关系进行了探讨,对属种的区分作了进一步界定。哺乳动物的研究显示,陕西蓝田地区晚中新世早期的气候可能比现代还要干旱。灞河动物群中松鼠类和林跳鼠类的出现,还表明了在这个温带开阔的草原环境中,尚有一些灌丛和林地。     

懒猴的牙齿形态观察

本文就云南所产懒猴的牙齿形态作初步观察。恒齿式为(2.1.3.3)/(2.1.3.3)=36;上门齿为异形齿,中门齿比侧门齿阔大,形态亦不同;上犬齿有性别差异,下犬齿特化为门齿形;前臼齿无论齿数和齿尖分布都与猕猴、金丝猴和长臂猿有较大差别,但齿尖分布却与树鼩有某些相似之点;下颌第1前臼齿犬齿化;在臼齿的齿尖分布方面,与猕猴、金丝猴相似,上颌M~3次尖架消失,只具3个齿尖。     

甘肃东乡首次发现熊亚科化石——龙担哺乳动物群补充报道之二(英文)

2006年作者在和政县发现了两件产自东乡龙担动物群的熊类化石:一完整下颌(HMV1422)和一个咬合在一起的头骨及下颌(HMV 1454)。熊类系龙担哺乳动物群中未曾描述过的新成员。这两件标本虽然有少许不同,但都和李亦征(1993)所记述的沂南熊Ursus(Protarctos)yinanensis十分接近,而被归入该种。该种修订后的鉴别特征是:头骨长头型,头长接近中等大小的现生黑熊,头骨最大宽约为最大长的一半;矢状嵴长,约为顶长的1/3;眶下孔与眼眶前缘相距近,两者均在M1上方;颧骨前端仅组成眼眶下缘,其后端止于关节窝前缘水平;硬腭短,齿列之后的腭长小于P4长的1.5倍或M2长的3/4。前臼齿数目全;P4原尖小,位于裂凹正内方;M1短长方形,宽/长～80%;M2跟座中长,M2宽/长56%～58%;M2长/M1长133%～153%。m1无前下后尖及前下内尖,分隔下三角座和跟座的横沟窄(前后),横沟中没有明显的嵴和沟;m2短于m1,其前、后接近等宽。与U.boeckhi相比,P4相对更小;臼齿相对更窄长;M1不呈五边形;M2跟座更大;m1横沟短,V形。现生熊亚科的6个种在分子和生化特性上非常接近,且其分异的时间非常短。这使以生化和分子生物学为研究手段的遗传学家越来越倾向于把它们归入同一个属,即Ursus。但是以形态特征为研究对象的古生物学家却大多依据形态上的明显差异而把它们分成多个属。不过古生物学家也常把欧亚大陆上新世-第四纪早期的熊类化石简单地归入Ursus一个属。在对比研究东乡熊化石时,我们对欧亚大陆同期的熊化石作了较仔细的观察,发现m1的形态变化在熊亚科的演化中分异显著,在分类中应具重要意义。结合头骨及牙齿的其他特征,这一时期熊类化石主要可以分为三组:1)m1形态简单者,无前下后尖和前下内尖,横沟表面基本光滑。2)m1具嵴形图案者,具前下后尖,但无前下内尖,在三角座后壁和横沟中形成V,Y或X形嵴。这一组熊类的m1和现生黑熊者最为接近。3)m1具前下后尖、前下内尖,次级附尖很发育,主尖及附尖多为圆锥形。这一组熊类的m1和现生棕熊者最为接近。属于第一组的有Baroth-Kopecz的U.boeckhi,沂南熊及Serrat d'en Vacquer的一件左下颌(1890年描述)。第二组包括产自Perrier,Weze,Layna,Wolfersheim等地点的熊类及Serrat d'en Vacquer的一件头骨及下颌(1892年描述)。第三组包括发现于欧洲众多地点(Val d'Arno,St.Vallier等)的U.etruscus。上述三组熊类在m1形态上的差异和组内变异的程度,使我们倾向于把它们分为不同的属,其属名分别应为:Protarctos,Euarctos和Ursus。Protarctos包括P.boeckhi(MN 14),P.ruscinensis(MN 15)和P.yinanensis(相当于MN 16-17)。Euarctos包括E.pyrenaicus(MN 15),E.minimus(MN 16-17)和现生美洲及亚洲的黑熊。而Ursus则包括U.etruscus(MN 17)及许多后期类型,如U.spelaeus等,以及现生的U.arctos(可能还有U.maritimus)。     

内蒙古额尔登敖包中始新世戈壁兔(哺乳纲:兔形目)新材料(英文)

描述了来自内蒙古二连盆地的戈壁兔新材料,并命名了一个戈壁兔新种Gobiolagus aliwusuensis sp.nov.。化石产于额尔登敖包剖面中阿里乌苏地点,传统地层划分中的下红层,时代约为中始新世。该种具有中等个体,P3主尖前壁具有小的附尖,P4颊侧有两个明显的尖。这些化石材料保存了戈壁兔材料中仅有的完整上齿列,其中的P2和M3形态是首次报道,为了解亚洲早期兔形类的演化增加了新的信息。     

对德日进和罗学宾所研究的山西榆社大后猫(Metailurus major)化石的再研究

德日进和罗学宾于1945年报道了山西榆社盆地发现的4件大后猫(Metailurus major)化石,但没有注明具体产地和层位。本文通过查询这些标本的原始资料,最终确定其产自榆社盆地晚上新世麻则沟组中部地层。其与前人报道的大多数晚中新世的Metailurus化石在时间上存在较大的间隔,是目前世界范围内发现的时代最晚的Metailurus化石之一。对这些标本的再研究表明,这些材料与M.major的正模及其他归入标本有较大的差别,应为一新种,将之命名为Metailurus ultimus。该种以体型大而粗壮,头骨在颧弓处特别宽、前半部形成一短宽的等边三角形,下颌水平支厚实、与颊齿列一起呈弧形向外明显凸出,上、下犬齿前后嵴上有明显的横向沟纹,P3相对较长、前附尖明显,P4前附尖和原尖都较大,p3前附尖小但明显,m1跟座非常退化至接近于无等特征区别于其他已知各种。     

Osteology and ecology of Megantereon cultridens SE311 (Mammalia; Felidae; Machairodontinae), a sabrecat from the Late Pliocene – Early Pleistocene of Senéze, France

Megantereon cultridens was a derived, Late Pliocene to Early Pleistocene sabrecat, and although fossils of animals referred to the genus and species have been found at several locations throughout Eurasia, most are fragmentary. However, the specimen SE311 from Senéze in France represents an almost complete and well-preserved skeleton, and this is only known from very few other sabrecats, thus providing a rare glimpse into the full anatomy of an unusual and derived sabrecat. In this monograph, we provide a complete overview of the anatomy of Megantereon cultridens SE311, and compare it with extant large felids, and the few other derived sabrecats from which ample fossil material is known, although most frequently representing several specimens. SE311 was a large specimen of M. cultridens and would have had a body mass of 100–110 kg and a head–body length or around 160 cm, which is similar to a small lioness or large male jaguar. Megantereon sp. were sexually dimorphic, and the size of SE311 suggests that it was a male. As with several other derived sabrecats, it was powerfully built, and had particularly robust forequarters with very well-developed muscle attachment sites, indicating a powerful forelimb and shoulder musculature. The neck was proportionally much longer than in extant felids, and the thoracic and particularly lumbar region was proportionally shorter, mimicking the condition in other derived sabrecats from which large parts of the vertebral column is known. Megantereon probably lived in open-forest environments and preyed on cervids, which were dispatched with a shearing bite from the hypertrophied and blade-like upper canines to the throat of the prey, while the prey was held immobile with the massive forelimbs, thus minimizing the risk of damage to the fangs.  © 2007 The Linnean Society of London, Zoological Journal of the Linnean Society , 2007, 151 , 833–884.     

Occurrence of Theropithecus sp. in the Late Villafranchian of Southern Italy and implication for Early Pleistocene "out of Africa" dispersals

Three cervical vertebrae of a large primate have been identified in the revision of the faunal assemblage collected during the late '70s from fissure fillings in the area known as Pirro Nord in southern Italy. By size the three vertebrae are comparable to the large fossil species Theropithecus oswaldi, however we prefer here to attribute the remains to Theropithecus sp. The Pirro Nord Theropithecus represents the second finding outside of Africa of this genus in association with Megantereon whitei, after the site of 'Ubeidiya. The biochronology of Pirro Nord faunal assemblage demonstrates that the arrival into Europe of Theropithecus occurred earlier than thought: in the range of approx 1.6-1.3 Ma. The identification of an European "African assemblage" (Theropithecus associated with Megantereon whitei) has consequences for interpretation of an "out of Africa" (genus Homo) event around the Plio-Pleistocene transition.     

陕西镇安黄家湾早更新世哺乳动物群及其伴生植物

记述了发现于陕西镇安黄家湾早更新世晚期的一个大型哺乳动物群。动物群包括哺乳动物4目、11科、24种,它们是：Canis variabilis, Hyaenidae gen. et sp. indet. , Homotherium sp. , Megantereon sp. , Lynx cf. shansius , Panthera pardus , Elephantidae gen. et sp. indet. , Equus qingyangensis , Hesperotherium sinense , Ancylotherium sp. , Megatapirus augustus, Rhinocerotidae gen. et sp. indet. , Dicerorhinus lantianensis, Sus sp. , Moschus moschi ferus , Cervus unicolor , Cervus sp. 1, Cervus sp. 2, Hydropotes sp. , Capreolus sp. , Strepsiceros annectens , Leptobos sp. , Bubalus sp. 和 Budorcas taxicolor等。动物群伴生植物孢粉分析表明,当时在化石产地生长着下列植物：Selaginella sp. , Pinaceae gen. et sp. indet. , Picea sp. , Cotinus coggygria , Juglans regia , Quercus sp. , Myrica rubra , Meliaceae gen. et sp. indet. , Celtis sp. , Oleaceae ( Syringa sp. ?) gen. et sp. indet. , Chenopodiaceae gen. et sp. indet. ,Kobresia sp. , Scrophulariaceae gen. et sp. indet. , Humulus sp. , Gramineae gen. et sp. indet. , Ranunculaceae gen. et sp. indet. , Sparganium sp. ,Celastraceae gen. et sp. indet. ,Elaeagnaceae gen. et sp. indet. ,Compositae gen. et sp. indet. ,Aremisia sp. , Xanthium sibiricum 和Carex sp.等。分析了动物群生活时栖息地的气候、植被和地貌特征,结果表明,动物群栖息在温暖、湿润、有森林、灌丛草地并富有水体的生境中,当时秦岭腹地存在着相当开阔的河谷地带,山势没有现在这么险峻,因此阻断秦岭南北动物交流的天然屏障当时可能还未真正形成,秦岭南北两侧的动物可以沿着开阔的河谷地带随季节和气候的变化互相扩散迁移。     

广西扶绥岩亮洞早更新世独角犀年龄结构的分析

岩亮洞是广西扶绥地区最近新发现的早更新世巨猿化石点,经过初步发掘,采集到了丰富的巨猿材料及大量伴生的哺乳动物化石。引人注目的是其中犀类化石居多,包括146颗完整的牙齿及十多件头后骨骼化石,从形态特征判断,这些犀类化石应属于独角犀的一新种Rhinoceros fusuiensis。岩亮洞巨猿动物群中的独角犀以种群丰度最大而不同于其他已知东亚地区的巨猿动物群中的独角犀类材料。本文从犀类牙齿的主尖釉质层、齿质暴露程度、咀嚼面的磨蚀程度等方面对岩亮洞独角犀的年龄结构进行了研究。该死亡群中至少有4头幼年个体、5头青年个体、5头成年个体和1头老年个体。依据牙齿磨蚀程度和牙齿萌出顺序对年龄结构的分析及统计显示,其中青年个体和成年个体最多,幼年个体次之,老年个体最少,其死亡的原因不是通常意义上磨耗型死亡,突发性的灾害可能是造成这种死亡年龄分布的主要原因。     

Megantereon adroveri from the Early Pleistocene of Taurida Cave,Crimea, and the European Lineage of Dirk-toothed Cats

Recent field surveys performed in the newly-discovered Taurida Cave (Crimea, Russia, Late Villafranchian, 1.8–1.5 Ma) enabled us to unearth dentognathic remains of the dirk-toothed cat Megantereon. Here we describe in detail the recovered remains further comparing it anatomically and biometrically with coeval Eurasian and African sites. The performed analysis suggests the inclusion of the Taurida remains in the hypodigm of the Villafranchain European species Megantereon adroveri, a medium-sized saber-toothed cat poorly known in Europe as a consequence of the scarcity and fragmentary nature of the known remains. Our results and the putative transitional characters displayed by the Taurida specimen support the idea put forward by previous authors of a continuous European lineage of dirk-toothed cats.

     

The hunters and the hunted revisited

The dietary niches of extinct animals, including hominids and predators, may be constrained using stable carbon isotope ratios in fossil tooth enamel.(13)C/(12)C ratios of many of the primates abundant in the faunal assemblages of Members 1 and 2 at Swartkrans, including cercopithecoids and Australopithecus (Paranthropus) robustus, and a range of other possible prey species, have been reported previously. Resulting suggestions of a mixed, or omnivorous, diet for A. robustus raise questions about niche overlap with coeval, larger brained Homo. Here we present(13)C/(12)C data from Homo and several large predators including Panthera pardus, Dinofelis sp., Megantereon cultridens and Chasmoporthetes nitidula in Member 1, and P. pardus and P. leo in Member 2, in order to compare the two hominid species and to determine likely predators of the various primates and other macrovertebrates. Results for three Homo cf. ergaster individuals are indistinguishable from those of A. robustus, showing that proportions of C(3)- and C(4)-based foods in their diets did not differ. P. pardus, Megantereon and Crocuta are shown to be likely predators of the hominids and Papio baboons in Member 1, while the Dinofelis individual concentrated on prey which consumed C(4)grasses. The hunting hyaenid C. nitidula preyed on either mixed feeders or on a range of animals across the spectrum of C(3)and C(4)variation. The data from Members 1 and 2 confirm a shift in leopard diets towards animals that consumed C(4)grasses.     

The African species Megantereon whitei from the Early Pleistocene of Monte Argentario (South Tuscany,Central Italy)

A partial skull and articulated postcranial elements of Megantereon whitei have been recorded during the 1950s from a karst deposit in the Monte Argentario area (Grosseto). These fossils recently became available for study. The bones are quite well preserved, included in a hard reddish matrix with calcareous clasts. The fossil is part of a faunal assemblage referred to the Late Villafranchian (Early Pleistocene). M. whitei from Monte Argentario is characterised by elongated upper canines, stronger than those of the Upper Valdarno (Tuscany) specimens and similar to the Pirro Nord (Apulia) fossil. The manus is robust, the first phalanges are quite long in comparison to the metacarpals. The Early Pleistocene European M. whitei represents an African element that took part in the faunal dispersal from Africa to Europe that occurred at the Plio-Pleistocene transition.     

A New Machairodont from the Palmetto Fauna (Early Pliocene) of Florida,with Comments on the Origin of the Smilodontini (Mammalia,Carnivora, Felidae)

South-central Florida’s latest Hemphillian Palmetto Fauna includes two machairodontine felids, the lion-sized Machairodus coloradensis and a smaller, jaguar-sized species, initially referred to Megantereon hesperus based on a single, relatively incomplete mandible. This made the latter the oldest record of Megantereon, suggesting a New World origin of the genus. Subsequent workers variously accepted or rejected this identification and biogeographic scenario. Fortunately, new material, which preserves previously unknown characters, is now known for the smaller taxon. The most parsimonious results of a phylogenetic analysis using 37 cranio-mandibular characters from 13 taxa place it in the Smilodontini, like the original study; however, as the sister-taxon to Megantereon and Smilodon. Accordingly, we formally describe Rhizosmilodon fiteae gen. et sp. nov. Rhizosmilodon, Megantereon, and Smilodon ( =  Smilodontini) share synapomorphies relative to their sister-taxon Machairodontini: serrations smaller and restricted to canines; offset of P3 with P4 and p4 with m1; complete verticalization of mandibular symphysis; m1 shortened and robust with widest point anterior to notch; and extreme posterior “lean” to p3/p4. Rhizosmilodon has small anterior and posterior accessory cusps on p4, a relatively large lower canine, and small, non-procumbent lower incisors; all more primitive states than in Megantereon and Smilodon. The former also differs from Megantereon and Smilodon gracilis by having a very small mandibular flange. Rhizosmilodon is the oldest known member of the Smilodontini, suggesting that the tribe originated in North America. Two more derived, similar-sized species evolved in parallel during the Blancan, Megantereon hesperus and Smilodon gracilis. The former is rarer, known only from the north-central and northwestern US, and presumably dispersed into the Old World. The latter is known from the eastern and southern US, and dispersed into South America.     

New sabre-toothed cats in the Late Miocene of Toros Menalla (Chad)

The Toros Menalla Late Miocene Formation (7 Ma), Djurab desert, Chad, has yielded a large number of vertebrate remains, and among them around twenty taxa of carnivores. Recent collections allow us to describe two sabre-toothed felids assigned to the genera Lokotunjailurus and cf. Megantereon. The former does exist in the Nawata Formation, Lothagam, northern Kenya with a slightly derived species and the TM specimens are considered as belonging to a new species. The latter cannot be identified to the species level, but it could be one of the earliest specimens of Megantereon known in the world and it would reinforce the hypothesis of an Old World origin for this taxon. Both allow us to put forward some biogeographical conclusions.     

南京汤山早期人类及南方几个猿人遗址的生活环境

南京汤山的早期人类的地质时代相当于中更新世晚期,距今12.7—50万年。该动物群是一个单调的北方型动物群,生活在寒冷期,相当于深海氧同位素的等10阶段,距今33—37万年。郧县的古人类与蓝田的公王岭动物群同时,为早更新世,距今100—140万年。它们生活在温暖期,相当于欧洲的Waalian暖期。与元谋人共生的元谋动物群(相当于元谋组的第四段)包括许多典型的北方型动物,如复齿鼠兔,泥河湾剑齿虎、麅、羚羊等,故它们生活在寒冷期,也属早更新世,距今140—190万年。