中国古动物馆珍品馆藏——锯齿

化石名称：锯齿似剑齿虎 Homotherium crenatidens 化石描述：近乎完整的头骨（侧面暴露其发育的显著裂齿）和下颌骨 生活时代：早更新世（距今约200万年前） 化石产地：安徽省繁昌县     

陕西省甸邑县发现大型植物化石

今年六月二十日,在陕西省旬邑县城东郊发现一处大型古植物化石.这是继在旬邑县境内发现大象、三趾马、剑齿虎、犀牛、鬣狗等动物化石之后的又一重大发现。这批古植物化石数量之多、种类之繁、石化之好是迄今比较罕见的。其植物个体的叶、枝、茎齐全,最粗的植物茎横断面直径达到1.75米,估计整株高度在35米以上;叶片化石的整体形态、叶脉纹理非常清晰;茎化石表皮酵似现存粗大松树茎的表面,茎内木质部化石的颜色为枣红色,非常     

伊朗新发现的中新世哺乳动物足迹的亲缘关系及其意义

伊朗晚中新世的几个地点新近发现了哺乳动物足迹化石。足迹化石在伊朗中北部分布在一套被称为上红组的厚层、混杂的泻湖-陆相地层序列的数个层位中;在伊朗北部的里海地区南部,则位于一套陆相沉积序列中。产自上红组的足迹以偶蹄动物类型为主,由于个体很小,可归入几种像羚羊一样大小的种;其他足迹则分别归入小型、中型和大型的鼬科和猫科食肉动物。产自伊朗北部的足迹化石主要为长鼻类,有些可能是犀牛,少数为偶蹄类足迹。根据上红组中发现的猫科动物(剑齿虎)足迹,可认为产足迹的地层年代为晚中新世,而产于伊朗北部古地中海边缘区沉积中的长鼻类足迹显示,地层的最大年龄为中新世最早期。这些足迹化石的发现填补了这一重要地区新近纪哺乳动物化石记录的空白。     

剑齿虎

本期封面上,您看到的是已绝灭的剑齿虎的复原象及其头骨化石。追本溯源,剑齿虎与虎虽然同宗,均属猫科动物,但两者揖别的时间较早。古生物学家分出一个剑齿虎亚科。剑齿虎渊源于渐新世的古剑虎。古剑虎身躯匀称,四肢细长,上犬齿并不很大,尾巴与现生虎很长的尾巴相似,看起来倒是积极捕食各种动物的能手。     

剑齿虎与机能解剖

大约一千二百万年前,在北美和欧亚的丛林和稀树干草原上,出现了一种新型的巨大的猫科动物——剑齿虎。我国的河南、山西、周口店等地就曾发现过这类动物的化石。剑齿虎的身材和体态如豹,因生有两颗细长、剑形的上犬齿而得名。与普通的猫科动物,如现代的狮、虎、豹以及剑齿虎的不具剑齿的祖先相比,剑齿虎的上犬齿的长是它们的一倍半,而宽还不足它们的一半。剑齿虎曾是一类非常成功的肉食动物,与现生猫科动物的无剑齿的祖先共同生存了数百万年之久,直到大约一万年前才最后绝迹。长期以来,古生物学家们一直对剑齿虎的剑齿的机能感到莫名其妙。象发现在美国洛杉矶沥青湖中的Smilodon,身材跟狮子差不多,可是却具有非常强有力     

南召发现的人类和哺乳类化石

本文记述的人类化石是一枚右下第二前臼齿,发现于河南省南召县鸡河右岸第二级阶地的堆积中。一起发现的哺乳类化石有剑齿虎、中国鬣狗、肿骨鹿、剑齿象、三门马和巨等二十一种。时代为中更新世。     

新的发现

新的发现甘肃兰州发现更新世晚期的赤鹿化石。──薛仰敬浙江义乌市塔山乡剡溪村发现恐龙蛋化石。──许文巨、傅健内蒙古大窑遗址又出土化石,其中有河套大角鹿、剑齿虎、熊、普氏羚羊、原始牛、转角羚羊、披毛犀等动物化石,在这些化石中还发现有人工打制的石器。──王...     

河南卢氏始新世灵长类一新属

河南卢氏上始新统卢氏组下部含脊椎动物化石层中,曾发现过好几种在第三纪早期哺乳类进化上很有意义的化石,例如:古齿兽科的副等尖齿兽(Paratriisodon),古剑齿虎(Eusmilus),始犬(Miacis),双锥兽(Dichobune)等。最近,在同一批材料中,又发现了一种新的跗猴类的灵长类化石,虽然只有一个不太完整的标本,但因我国已知的古老灵长类化石的材料很少,所以还是一个较有意义的发现。     

安徽泗洪县下草湾金龟化石*

下草湾发现的脊椎动物化石中,最多的是龟类甲壳的残片,多数都是在地面拾到的零星碎块,无法鉴定仅有采自河岸赭红色砂土层中的一个保存较好的破碎甲壳,经定为一种似与现代的金龟相近的淡水龟;此外,在拾自地面的碎块中有属于另一个体的完整的剑腹甲一块,亦可归入同一种内。龟类化石在淮河流域的发现还是第一次。     

陕南镇巴早寒武世似软舌螺化石一新种--Torellella bisulcata sp.nov.

对采自陕西镇巴小洋剖面下寒武统西蒿坪段的似软舌螺类(hayolithelminths)化石进行了研究,描述了一新种Torellella bisulcata sp．nov．,其主要特征为：磷质管状壳体,横切面透镜状,壳管的两个宽面凸度不等,一面为弧状,另一面扁平;壳管直或微弯曲,在壳管的两个窄的侧面各具一纵向浅凹沟,壳面光滑或饰有微弱的横向纹线。简要地讨论了似软舌螺类化石的生物亲缘关系,认为迄今为止,其仍为分类位置不明的化石类别。西蒿坪段中下部产有三叶虫颊刺和颈刺,表明此段沉积地层属于下寒武统筇竹寺阶而非梅树村阶。     

小鼩鼱(食虫目:鼩鼱科)辽宁省新纪录

在整理采自辽宁省新宾县鼩鼱属(Sorex)标本时,发现小鼩鼱(S.inutus Linnaeus,1766)为辽宁省新纪录。主要特征为上颌第二单尖齿小于第一、三单尖齿,第五单尖齿小,约为第四单尖齿的2/3高。下颌门齿向前延伸甚长,其上切缘有3个深缺刻,犬齿小,是下前臼齿2/3高。     

The fragment of a hominid tooth from the Holstein II period from Stuttgart-Bad Cannstatt, S-W Germany

Through systematic excavations in a loamy layer of a travertine quarry at Stuttgart-Bad Cannstatt in 1981, a crown and a root of a tooth were discovered. The stratigraphic and TL-dating give a geochronological age of Holstein II or nearly 300 Ky. In 1981 these two fragments were published and diagnosed by their micromorphological structure by the present author as a lower left hominid canine. Adam (1986) and Schott (1989) pointed out that the two fragments must be of one tooth ofCervus elaphus ignoring the fragmentary preservation of the crown and the differences of the shape of the preserved cervical part of the crown in contrast to that of the isolated root. The overall morphology, including the micromorphology together with the metric evaluation and a comparison with the teeth ofCervus elaphus, determine the two fragments as a hypoplastic crown of a left lower human canine and a root which belongs possibly to an upper molar.     

记广西田东却林缅甸先炭兽的新材料

记述了产自广西田东县却林那读组中一残破的缅甸先炭兽 (Anthracokeryxbirmanicus)头骨。通过对化石的描述 ,对该种特征进行了补充和分析 ,并认为其终生生长的上犬齿可能是用来作为争夺领域和配偶的武器。终生生长的上犬齿的发现 ,证明炭兽类具有性双形。将那读动物群和缅甸邦唐动物群进行对比 ,认为那读组的时代很可能有一部分属于中始新世     

Canine "honing" in Australopithecus afarensis

The maxillary canines of Australopithecus afarensis show a distal wear facet that extends from the apex of the crown to a point near the distal cingulum. Although these facets bear a superficial resemblance to the honing facets found on the projecting portions of the canines of other anthropoids, a more detailed examination provided in this paper shows that they are not homologous or functionally equivalent. The facets are not related to the use of the maxillary canine as a weapon or as an additional masticatory surface. Instead, their presence in A. afarensis represented a blunting or dulling of the posterior edge of C so that its occlusion with P3 would be consistent with cheek tooth occlusion.     

SEX DETERMINATION OF THE CALIFORNIA SEA LION (ZALOPHUS CALIFORNIANUS CALIFORNIANUS) FROM CANINE TEETH

Size of canine teeth from California sea lion ( Zalophus californianus californianus ) carcasses is shown to be useful in determining the sex of animals which have missing genitalia or which are otherwise of unknown sex. A total of 267 canine teeth from carcasses of 68 males and 43 females were measured along five axes. Of root and crown measurements of upper and lower canines, males and females overlapped only in root thickness of upper canines. A multivariate ANOVA showed a significant difference in the size of canines between upper and lower canines, and between males and females. Stepwise discriminant analysis produced discriminant functions for upper and lower canines for determining sex of unknown-sexed California sea lions. A separate set of canine teeth from 39 male and 49 female California sea lions was correctly classified without prior knowledge of sex by visual inspection and by the two discriminant functions.     

贵州桐梓新发现的人类化石

本文主要描述1983年在贵州桐梓县岩灰洞新发现的四枚人类牙齿化石,并对1972年在该洞发现的两枚人类牙齿一并作进一步的讨论。经研究表明,它们的形态特征与北京猿人非常相似,而与早期智人有着明显的差异。因此,我们认为桐梓人类化石似应属直立人(Homoerectus),而不是以前认为的早期智人(early Homo sapiens)。该遗址的地质时代为更新世中期。     

安徽潜山新发现的钝脚类头骨化石

本文记述了发现于安徽潜山盆地中古新统望虎墩组上段的一件较为完整的钝脚类头骨化石,将其归入 Altilanbda 属中,并建立—新种——余井高脊兽(A. yujingensis sp. nov.).     

Canine size, shape, and bending strength in primates and carnivores

Anthropoid primates are well known for their highly sexually dimorphic canine teeth, with males possessing canines that are up to 400% taller than those of females. Primate canine dimorphism has been extensively documented, with a consensus that large male primate canines serve as weapons for intrasexual competition, and some evidence that large female canines in some species may likewise function as weapons. However, apart from speculation that very tall male canines may be relatively weak and that seed predators have strong canines, the functional significance of primate canine shape has not been explored. Because carnivore canine shape and size are associated with killing style, this group provides a useful comparative baseline for primates. We evaluate primate maxillary canine tooth size, shape and relative bending strength against body size, skull size, and behavioral and demographic measures of male competition and sexual selection, and compare them to those of carnivores. We demonstrate that, relative to skull length and body mass, primate male canines are on average as large as or larger than those of similar sized carnivores. The range of primate female canine sizes embraces that of carnivores. Male and female primate canines are generally as strong as or stronger than those of carnivores. Although we find that seed-eating primates have relatively strong canines, we find no clear relationship between male primate canine strength and demographic or behavioral estimates of male competition or sexual selection, in spite of a strong relationship between these measures and canine crown height. This suggests either that most primate canines are selected to be very strong regardless of variation in behavior, or that primate canine shape is inherently strong enough to accommodate changes in crown height without compromising canine function.     

禄丰古猿地点的猪尾鼠类化石

本文记述亚洲首次发现的猪尾鼠类化石。材料系1983年于云南禄丰古猿地点最晚中新世石灰坝组采集到的,计有代表两属三种——Platacanthomys dianensis sp.nov.,Typhlomysprimitivus sp.nov.和T.hipparionum sp.nov.的百余枚牙齿。文中除对新种的形态作了描述和对比外,还对猪尾鼠类的分类位置及系统发育作了探讨。     

Unicausal theories of human canine evolution: are they sufficient?

Most theories of human canine evolution are unicausal and only purport to explain size and related shape changes in human canines. The present work tests whether one of the morphological changes, dulling of the distal edge of the maxillary canine, can be entirely explained as a byproduct of changes in the overall shape of the canine. The data show that the distal edge of maxillary canines of A. afarensis became far duller than would be predicted from changes in crown shape. The greater than expected dullness of the distal edge can be explained by evolutionary changes in the genetic field for cheek tooth morphology. This suggests that human canine evolution is complex and cannot be accounted for by unicausal theories.