湖北建始县又发现巨猿牙齿化石

1970年,中国科学院古脊椎动物与古人类研究所在我省建始县高坪龙骨洞中发现了5枚巨猿牙齿化石和大量的哺乳动物化石。经研究,巨猿牙齿化石的时代为早更新世晚期。     

湖北郧西黄龙洞更新世晚期人类牙齿

对2004—2006年在湖北省郧西县黄龙洞发现的7枚更新世晚期人类牙齿进行了观测与分析, 在此基础上与相关的化石人类及近代现代人类标本进行了对比。本研究发现:黄龙洞人类牙齿总体特征与现代人接近, 同时也保留部分可能属于更新世晚期人类的特点, 包括前部牙齿(侧门齿与犬齿)尺寸及粗壮程度都明显大于现代人。黄龙洞人类牙齿呈现的铲形门齿、双铲形门齿及臼齿釉质延伸说明,当时人类已经具有了东亚人群的典型牙齿形态特征。     

广西扶绥南山洞新发现的人类化石和蒙古野驴化石——末次冰期华南气候变化的哺乳动物化石新证据

广西扶绥县南山洞发现人类化石及哺乳动物化石。人类化石包括2枚智人牙齿化石,分别是左下第三臼齿和右下第二臼齿,其形态特征与广西其他山洞发现的智人化石相似,归入晚期智人。哺乳动物化石多为华南大熊猫———剑齿象动物群成员,时代属更新世晚期。该地点新发现的蒙古野驴化石属华南晚更新世动物群的首次发现。南山洞所有化石发现于洞内浅褐色砂质粘土中,堆积物第二层钙板层的铀系年龄为30—40ka。蒙古野驴的出现暗示中国南方大陆可能在末次冰期出现过干冷的气候环境。     

广西柳江土博出土的人牙化石及共生的哺乳动物群

在广西柳江县土博公社发现一洞穴,地层中含有人类化石和哺乳动物化石。其时代初步定为更新世晚期。人类化石仅是牙齿九枚,根据其形态特征,这些材料的系统地位似应与柳江人相当,分类上可归属晚期智人。     

山东新泰乌珠台人类牙齿的形态学特征

近些年在东亚发现的晚更新世现代人化石及其研究使得关于该地区现代人起源问题更加复杂,更多该时段人类标本的研究有助于对其有更清晰的认识。1966年在山东新泰乌珠台发现一枚古人类下颌臼齿,吴新智和宗冠福(1973)对其进行了报道,而后再无详细研究。本文将使用牙齿非测量性状的半定量化(分级)、齿冠外轮廓形状的几何形态测量、基于显微断层扫描(Micro-computed tomography 或micro-CT)的釉质厚度、釉质厚度分布规律和齿质表面三维结构复原等方法对乌珠台人类牙齿进行综合研究,进而对东亚晚更新世古人类牙齿形态特征变异有一个进一步的了解。结果显示,乌珠台人类牙齿的形态特征基本与现代人接近,但其所表现出的三角座横脊、Y型齿沟排列、原附尖在现代人中出现率较低,而更多发现在直立人或尼安德特人中。相对于东亚其他晚更新世现代人,乌珠台M3所表现出的特征组合具有特殊性,增加了东亚晚更新世现代人的牙齿形态特征多样性。未来研究可尝试测定乌珠台人类牙齿的绝对年代,以更好的将其归入到现代人演化序列中去。     

福建清流发现的人类牙齿化石

本文记述福建省境内首次发现的出自地层的古人类化石。标本为晚期智人的一枚左下第一臼齿。根据对化石产地的地质、地貌以及伴生哺乳动物化石种类的分析,表明其时代为晚更新世晚期。     

记陕西长武晚更新世人牙及共生哺乳动物化石

1972年10月,作者在陇东进行第四纪哺乳动物和地层考察期间,在陕西省长武县城关附近的窑头沟及鸭儿沟观察了几个晚更新世地层剖面,并且在这些剖面的中、下部灰色砂质土及砂砾层找到了许多石器和少量哺乳动物化石。此外,还获得了一枚化石智人牙齿。通过这些材料的简单记述(石器材料将另文发表),作者希望对黄土高原晚更新世哺乳动物和地层时代的认识有所帮助。     

山东沂源猿人化石

本文记述了山东省沂源县骑子鞍山出土的一件人类头盖骨残片和七枚牙齿化石。它们的形态特征与北京猿人相似,在分类系统上应属直立人,与人类化石伴生的哺乳动物群的性质与周口店动物群相同,地质时代为中更新世。     

海南“三亚人”遗址1992年发掘报告

本文记述的是海南三亚发现的石器时代洞穴遗址,地质时代为晚更新世末或全新世初期。哺乳动物组合为东洋界动物群,石制品在类型上或加工方式上与两广地区相同时代的文化类型比较接近。人类牙齿属晚期智人。     

蔚县盆地2017-2018年旧石器考古调查简报

蔚县盆地地处泥河湾盆地（广义）的东南端,是更新世人类活动的重要区域。2017-2018年,中国科学院古脊椎动物与古人类研究所等在盆地内开展系统的旧石器考古调查,新发现并确认了27处旧石器地点。相关地貌、地层对比显示,新地点年代可大致分为中更新世和晚更新世晚期两个阶段,文化遗物分别埋藏于泥河湾河湖相堆积和黄土堆积中。中更新世石制品类型包括石核、石片、石器和断块等,原料以火山岩为主,均采用锤击法进行剥片和修理石器;晚更新世晚期遗址包括石核、石片和细石叶等,原料以白云岩和燧石居多,火山岩次之,以硬锤锤击法为主要剥片技术,软锤技术少量发现。对石制品初步分析表明,蔚县盆地中更新世地点表现出了一套与阳原盆地早-中更新世不同的原料及石制品组合,且在蔚县盆地晚更新世晚期存在小型石片石器和细石器两种工业。本次调查扩大了泥河湾盆地古人类活动的地理范围与文化内涵,为揭示泥河湾盆地（广义）早期人类的迁徙与适应行为提供了有价值的线索。     

MANDIBULAR DENTAL ONTOGENY OF RINGED SEALS (PHOCA HISPIDA)

X-rays of mandibles from ringed seal fetuses ( n = 15), newborns ( n = 12), and young-of-the-year ( n = 11), collected up to early June, were examined for the presence, location, and eruption patterns of deciduous and permanent teeth. The presence of a neonatal line and cementum in permanent canines was determined microscopically. Fetuses sampled in October-November had only unerupted, deciduous tooth germs, but by late January there were robust, deciduous teeth at il-2 pc2-4 and small permanent teeth at 11-2 Cl PCl-5. In newborns collected in early April, 109 of 143 (76%) deciduous teeth were resorbed completely. The remaining 34 deciduous teeth were partially resorbed; six (18%) had erupted and likely would be shed. By late April young-of-the-year had no deciduous teeth remaining. In newborns 54% of the permanent teeth (102/188) were erupted < 2 mm, and by late May the permanent dentition was erupted fully. The neonatal line first appeared in the canine teeth of young-of-the-year collected in mid-April and was 100% present after early May. There was no cementum apparent on any canine collected up to early June. Two seals were missing one and two permanent incisors, respectively. No supernumerary teeth or morphological variants were observed.     

步氏巨猿牙齿大小上的变异性和南方古猿类食性假说

步氏巨猿牙齿大小上的变异性表明,在柳城巨猿洞局部地区的堆积中可能有少量时代稍晚的巨猿牙齿标本。晚期步氏巨猿与早期的相比,后部齿显著增大而前部齿则无显著差异。从步氏巨猿牙齿在大小上的演化趋势来看,南非南方古猿类中的纤细类与粗壮类之间在齿列比例上的不同不一定意味着其食性上有大的差异,纤细类与粗壮类也未必有“属”这一分类级别上的差异。     

Development of larval and transformed teeth in Ambystoma mexicanum (Urodela, Amphibia): an ultrastructural study

Odontogenesis of early larval non-pedicellate teeth, late larval teeth with a more or less distinct dividing zone and fully transformed pedicellate teeth in Ambystoma mexicanum (Urodela) was studied to obtain insights into the development of differently structured teeth in lower vertebrates. Using transmission electron microscopy we investigated five developmental stages: (1) papilla; (2) bell stage (secretion of the matrix begins); (3) primordium (mineralization and activity of ameloblasts starts); (4) replacement tooth (young, old); and (5) established, functional tooth. Development of the differently structured teeth is largely identical in the first three stages. Mineralization takes place in apico-basal direction up to the (prospective) pedicel (early and some late larvae) or up to the zone that divides the late larval and transformed tooth in pedicel and dentine shaft (pedicellate condition). Mineralization starts directly at the collagen and by means of matrix vesicles. First odontoblasts develop small processes that extend to the basal lamina of the inner epithelial layer of the enamel organ. The processes are small and lack organelles in early larval teeth, but become larger, arborescent, and contain some organelles in late larval and transformed teeth. The processes are surrounded by unmineralized matrix (predentine). Odontoblasts at the basis of the teeth, at the pedicel, and in the zone of division do not develop significant cytoplasmic processes that extend into the matrix. Cells of the inner enamel epithelium differentiate to ameloblasts that secrete the enamel. In the early larval tooth they show an extensive basal labyrinth that becomes regressive when the enamel layer is completed. In late larval and transformed teeth, however, a large cavity arises between the basal ruffled border of ameloblasts and their basal lamina. This cavity appears to mediate amelogenesis. A small apical zone in early, but not in late larval teeth directly below the thin enamel layer consists of enameloid and is free of dentine channels.     

中国早期智人牙齿化石

中国目前较为可靠的早期智人牙齿材料应包括在巢县、许家窑、长阳、周口店新洞和桐梓发现的人类牙齿化石,代表一类与早期组早期智人相当或十分相近的古人类。丁村人类牙齿化石可能是代表晚期组早期智人也可能是代表解剖学上的现代智人。就牙齿材料而言,尚无充分的证据能表明在中国曾同时存在过两种类型的早期智人。     

Associations in emergence age among permenent teeth

Associations in the timing of emergence among the permanent teeth of Boston children were obtained from a mixed longitudinal growth study of 414 Caucasian twin pairs examined annually. Correlations were estimated by the method of maximum likelihood for corresponding left-right teeth, upper-lower teeth, and all paired combinations from central incisor to second molar in a jaw quadrant of each sex. Strong positive correlations in emergence timing prevailed throughout the dentition. Principal component analyses on correlation matrices of jaw quadrant relations for boys and girls in the maxilla and mandible showed that three components effectively explained the emergence associations among the seven permanent teeth in each jaw quadrant. Factor analytic techniques further illustrated the nature of the three components and showed the emergence relations to be essentially the same in the maxilla and mandible for both sexes. The first component was a general maturation factor influencing all of an individual's teeth to be simultaneously early or late in emerging. The remaining two components were a molar factor, affecting almost exclusively the emergence timing of the permanent first and second molars, and a duration factor that affected the duration of the emergence process for non-molar teeth, contrasting particularly the incisors and premolars.     

Small Theropod Teeth from the Late Cretaceous of the San Juan Basin,Northwestern New Mexico and Their Implications for Understanding Latest Cretaceous Dinosaur Evolution

Studying the evolution and biogeographic distribution of dinosaurs during the latest Cretaceous is critical for better understanding the end-Cretaceous extinction event that killed off all non-avian dinosaurs. Western North America contains among the best records of Late Cretaceous terrestrial vertebrates in the world, but is biased against small-bodied dinosaurs. Isolated teeth are the primary evidence for understanding the diversity and evolution of small-bodied theropod dinosaurs during the Late Cretaceous, but few such specimens have been well documented from outside of the northern Rockies, making it difficult to assess Late Cretaceous dinosaur diversity and biogeographic patterns. We describe small theropod teeth from the San Juan Basin of northwestern New Mexico. These specimens were collected from strata spanning Santonian – Maastrichtian. We grouped isolated theropod teeth into several morphotypes, which we assigned to higher-level theropod clades based on possession of phylogenetic synapomorphies. We then used principal components analysis and discriminant function analyses to gauge whether the San Juan Basin teeth overlap with, or are quantitatively distinct from, similar tooth morphotypes from other geographic areas. The San Juan Basin contains a diverse record of small theropods. Late Campanian assemblages differ from approximately co-eval assemblages of the northern Rockies in being less diverse with only rare representatives of troodontids and a Dromaeosaurus-like taxon. We also provide evidence that erect and recurved morphs of a Richardoestesia-like taxon represent a single heterodont species. A late Maastrichtian assemblage is dominated by a distinct troodontid. The differences between northern and southern faunas based on isolated theropod teeth provide evidence for provinciality in the late Campanian and the late Maastrichtian of North America. However, there is no indication that major components of small-bodied theropod diversity were lost during the Maastrichtian in New Mexico. The same pattern seen in northern faunas, which may provide evidence for an abrupt dinosaur extinction.