中国中侏罗世哺乳动物研究新进展

本文介绍了中国北方东部地区发现的几种中侏罗世哺乳动物:纤细辽兽、獭形狸尾兽、远古翔兽和粗壮假碾磨齿兽,除纤细辽兽发现于辽宁凌源房身九龙山组外,其他3种哺乳动物化石均发现于内蒙古宁城道虎沟地区的髫髻山组.这些哺乳动物化石的发现不仅丰富了我国中侏罗世生物群的组成,加深了人们对于中侏罗世哺乳动物多样性的认识,而且为解决我国北方东部地区晚中生代地层的划分和对比提供了可靠的古生物证据.     

中国辽西中侏罗世地层发现船颌翼龙新属新种

根据不完整的化石骨架, 建立船颌翼龙一新属新种: 李氏凤凰翼龙。它产自辽西中侏罗世的髫髻山组。具有以下特征: 上颌有11对以上牙齿, 最后一枚牙齿位置靠后, 位于眶前孔后下角的下方。翼掌骨长度大约为肱骨的55%。凤凰翼龙的发现不但增加了船颌翼龙的新成员, 而且对船颌翼龙的古地理分布提供了重要信息。它代表目前为止最早的船颌翼龙类。为我们了解船颌翼龙的起源和演化具有重要意义。     

粗壮假碾磨齿兽的发现及其科学意义

本文简要回顾了蜀兽类哺乳动物的研究历史,论述了在哺乳动物牙齿演化和中生代陆相地层对比研究中的科学意义。粗壮假碾磨齿兽的发现有力地支持了哺乳动物中“三磨楔齿形臼齿趋同演化”的假设,并再一次以直接的化石证据表明内蒙古宁城道虎沟地区含蜀兽类化石地层的时代为中侏罗世。     

辽宁西部一新的帆翼龙类化石

根据发现于辽西朝阳九佛堂组一具有部分头骨的不完整骨架,命名一新的帆翼龙--赵氏龙城翼龙(新属新种).头骨和牙齿形态显示龙城翼龙与宽齿帆翼龙的关系要比与其他翼龙的关系密切,龙城翼龙是目前辽西九佛堂组中发现的唯一的帆翼龙类.帆翼龙科原仅一属种,发现于英国早白垩世地层中,辽西早白垩世新帆翼龙的发现,不但扩大了其地理分布,也证明辽西是晚侏罗世至早白垩世翼龙辐射、分异的重要地区.这对研究翼龙的起源和演化有重要意义.     

中国地质学会2014年度“十大地质科技进展”

<正>(1)从中国侏罗纪神、仙二兽再论哺乳动物起源:中国科学院古脊椎动物与古人类研究所毕顺东、王元青、孟津等人根据辽宁建昌发现的160 Ma前的6件相当完整的哺乳动物化石命名了贼兽类2个新属3个新种:陆氏神兽(Shenshou lui)、玲珑仙兽(Xianshou linglong)和宋氏仙兽(X.songae),首次从头骨、下颌、牙齿和头后骨骼等方面,全面地揭示了贼兽类的形态学特征。这项研究还澄清了有关贼兽类牙齿同源性、定位、咬合关系等方面的争议,并建立了一个新的哺乳     

前言

翼龙类是已绝灭生物中最迷人和充满神秘色彩的动物, 由于最近几年一些特殊化石的发现, 使人类对这些飞行的爬行动物的古生物学和演化历史理解更加深入。辽西及其周边地区中晚侏罗世到早白垩世一些重要的发现, 包括世界上第一件带胚胎的翼龙蛋化石, 处于演化过渡类型的达尔文翼龙以及一些新物种的发现频率, 远远高于世界其它地方。为了使这一发现在国际上充分展示, 加强国际之间的合作与交流, 中国地质调查局决定于2010年8月上旬在中国北京召开第三届国际翼龙学术研讨会“Flugsaurier 2010”。这是继在法国、德国分别于2001年、2007年成功召开的第一届、第二届之后的第三届国际翼龙学术研讨会。     

内蒙古鄂尔多斯地区早白垩世新的翼龙类化石

发现于内蒙古鄂托克旗召稍早白垩世罗汉洞组的一件不完整翼龙类下颌标本,以下颌愈合部长且平直、齿骨侧嵴发育、近圆形齿窝沿侧嵴之上的齿骨侧面上半部分自前向后呈直线排列、齿窝直径(2~2.5 mm)前后变化较小、相邻齿窝的间距约为齿窝直径的一半、下颌牙齿密度为3枚/cm等特征,可归入梳颌翼龙科(Ctenochasmatidae),且代表一新属种——郝氏鄂托克翼龙Otogopterus haoae gen.et sp.nov.。该化石是继鄂托克旗新召准噶尔翼龙科的平颌鄂尔多斯翼龙Ordosipterus planignathus之后在内蒙古鄂尔多斯地区发现的第2件确切翼龙类材料,丰富了这一地区早白垩世脊椎动物群的组成。该翼龙也是继甘肃庆阳环河翼龙Huanhepterus quingyangensis之后在鄂尔多斯盆地发现的第2种梳颌翼龙科化石,进一步扩大了鄂尔多斯盆地梳颌翼龙科的地理分布范围,同时表明鄂尔多斯盆地是继辽宁西部之后梳颌翼龙科在中国的又一重要分布区。     

辽西早白垩世-新的鸟掌龙类化石

根据发现于辽宁省西部下白垩统义县组的一近乎完整翼龙骨架，确立了鸟掌龙类一新属新种：崔氏北方翼龙Boreopterus cuiae gen．et sp.nov．。崔氏北方翼龙以其数量多的牙齿，且前部的九对牙齿大于后部的牙齿，上下颌的第四对牙齿稍微大于第三对等特征不同于辽西及其周边地区所发现的任何具有头骨保存的翼龙类。总的来说，     

记辽宁一新翼龙化石（喙嘴龙亚目）

记述了辽宁北票四合屯炒米甸子组中一新翼龙化石,该翼龙个体极小,两翼展开仅约４０ｃｍ。化石具有同形齿、长尾、极短的翼掌骨和非常发育的后肢第Ⅴ趾等特征,因而无疑可归入喙嘴龙亚目喙嘴龙科（Ｒｈａｍｐｈｏｒｈｙｎｃｈｉｄａｅ）,并代表一新属种弯齿树翼龙（Ｄｅｎｄｒｏｒｈｙｎｃｈｕｓｃｕｒｖｉｄｅｎ－ｔａｔｕｓｇｅｎ．ｅｔｓｐ．ｎｏｖ．）。该化石是我国及东亚晚侏罗世喙嘴龙类翼龙的首次记录,它的发现有力地表明包括中华龙鸟和孔子鸟在内的辽西四合屯化石层的地质时代应为晚侏罗世。     

中国辽宁中华侏罗兽的发现代表早期哺乳动物演化的一个新里程碑

真兽类哺乳动物是现代最为丰富多彩的哺乳动物类群,其起源和早期演化是国际科学界高度关注的科学问题之一。中国辽宁中侏罗世髫髻山组产出的中华侏罗兽是目前世界上发现的最古老的真兽类哺乳动物,代表了早期哺乳动物演化的一个新里程碑。研究表明,中华侏罗兽的发现将以前国际上的白垩纪化石记录提前了3500万年,填补了早期哺乳动物演化的化石记录间隔,帮助校正了现代基于DNA方法研究的哺乳动物演化历史,并与基于DNA方法测定的真兽类哺乳动物起源时间的研究结果相吻合,为哺乳动物演化历史建立了以化石为标准点的新标尺。中华侏罗兽的精确年龄有助于确定真兽类哺乳动物与其它哺乳动物,如后兽亚纲(它们的后代包括有袋类,如袋鼠)和单孔类(如鸭嘴兽),分异发展的时间。     

辽西首次发现保存毛发和软件的中生代哺乳动物化石

中国辽西地区素以产出丰富多彩的中生代热河生物群闻名于世。特别是近几年来，该区大量长羽毛的恐龙、原始鸟类、原始哺乳类和被子植物化石的发现更加引起了国际科学界的极大关注。1997年秋，作者在辽宁北票四合屯地区发现了一块完整的保存有毛发和软体印痕的对齿兽类哺乳动物化石。身体保存有手发和软体印痕的中生代哺乳动物化石在世界上也是罕见的。对对于研究对齿兽形态结构、生物习性、系统关系等方面均具有重要意义。     

A New Symmetrodont Mammal with Fur Impressions from the Mesozoic of China

Western Liaoning of northeastern China is world-renowned for the Mesozoic Jehol biota, especially for yielding many feathered dinosaurs, primitive birds, mammals and fossil angiosperm. This paper describes a complete specimen of a symmetrodont mammal with well-preserved hairs and soft tissue from the basal part of the Yixian Formation in the Sihetun area, Beipiao, western Liaoning. It is significant for understanding the morphology, osteology, phylogeny and life habits of Mesozoic symmetrodont mammals.     

Probabilistic Analysis of Suture Lines Developed in Ammonites: The Jurassic Examples of Hildocerataceae and Hammatocerataceae

Ammonites are extinct molluscs belonging to Class Cephalopoda which lived during the Mesozoic Era. Their usefulness in Jurassic and Cretaceous paleontology and biostratigraphy studies has been widely proved. They have been studied by several authors worldwide to achieve information regarding their habitats and the climate of the world in past eras. A probabilistic analysis of the paleo-environmental causes that generated complex suture lines in ammonites has been made by means of coherent upper conditional previsions defined with respect to Hausdorff outer measures. In particular, studies have centered on the role of hydrostatic pressure.     

Stratigraphy and Geochronology of Vertebrate Fossil‐Bearing Jurassic Strata from Linglongta,Jianchang County,Western Liaoning,Northeastern China

Northeastern China contains widely distributed Jurassic terrestrial strata that have yielded many spectacular mammal and pterosaur fossils, in addition to feathered dinosaur fossils and more recent discoveries from Jianchang, particularly from western Liaoning. However, the fossil-bearing stratigraphic succession, regional correlation, and age estimates of the fossils found in Jianchang County and nearby areas have been contentious. Here, we report on the vertebrate fossil-bearing Jurassic stratigraphy from Linglongta, Jianchang County, western Liaoning, including a SHRIMP U-Pb zircon date unambiguously associated with the fossil horizons. The primary goal was to determine the vertebrate fossil-bearing succession. A further aim was to provide age estimations for the fossil-bearing horizon as well as the earliest appearance of feathered dinosaurs, the eutherian–placental clade, and transitional pterosaurs. Field investigations showed that the vertebrate fossil-bearing stratigraphic succession in Jianchang County mainly consists of basal andesites overlain by rhythmic tuffs and tuffaceous lacustrine sediments, with the upper intermediate or acidic lavas interbedded with laminated more or less tuffaceous lacustrine deposits. This sequence correlates well with the Middle Jurassic Lanqi/Tiaojishan Formation in northeastern China. Detailed and accurate field observations showed that the well-preserved vertebrate fossils were buried in either the middle or the upper fine-grained laminated lacustrine deposits. Previous and current SHRIMP U-Pb zircon dates provide an age estimation of 161–159 Myr for the fossil-bearing horizon and vertebrates. This indicates that the earliest appearance of feathered dinosaurs here was more than 159 Myr ago and unquestionably older than Archaeopteryx from Germany, making these the earliest known feathered dinosaurs in the world. Furthermore, the eutherian–placental clade and the known transitional pterosaurs first emerged no later than 161 Myr. The vertebrate assemblage unearthed recently from Linglongta and neighboring areas in Jianchang County belongs to the Daohugou Biota. In addition to feathered dinosaurs, this biota was characterized by mammals, primitive pterosaurs, insects, and plants and was present in Inner Mongolia, western Liaoning, and northern Hebei in northeastern China during the Middle–Late Jurassic.     

广元恐龙化石埋藏地沙溪庙组地球化学特征及对物源区和古风化作用的指示

广元恐龙化石埋藏地是四川盆地中侏罗世重要的恐龙化石点,恐龙化石埋藏于中侏罗统沙溪庙组之中。笔者对该恐龙化石埋藏地沙溪庙组泥质岩的常量元素、微量元素和稀土元素特征进行了研究,并根据泥质岩的地球化学特征讨论了物源区性质、构造背景以及物源区的风化特征。主量元素和稀土元素表明其物源区以长英质岩石为主,构造背景为被动大陆边缘:指示化学风化程度的CIA指数及成分成熟度的ICV指数,表明物源区经历了中等的化学风化作用,反映了中侏罗世恐龙生活在半干旱的古气候环境之中。     

大兴安岭─燕山地层分区中、新生代地层

对大兴安岭和燕山北部的中生代地层，进行了系统的总结。侏罗纪早中期为含煤地层，晚期为以兴安岭群为代表的火山堆积；白垩纪早期为火山－沉积含煤地层，晚期为红层。第三纪以二连盆地合大量哺乳动物群的杂色沉积为特征。     

Titans of the skies: azhdarchid pterosaurs

Pterosaurs, the flying reptiles of the Mesozoic, often play second fiddle in popularity to their contemporaries, the dinosaurs. Such treatment conceals the remarkable diversity and biology of this group: not only were pterosaurs the first vertebrates to achieve powered flight, but they also existed for 160 million years—longer than any other flying vertebrates. Named after the Uzbek mythical dragon 'azhdarkho', the Azhdarchidae are among the most enigmatic of all pterosaurs. As with most pterosaurs, azhdarchid remains are rare, and their fossil record is largely represented by isolated bones or incomplete skeletons. Despite the collection of azhdarchid fossils over the last 100 years, recognition of these pterosaurs as a distinct group was not achieved until relatively recently. It is now clear that the azhdarchids were a highly successful group that probably first appeared in the Early Cretaceous, gradually spreading across the globe until the latest Cretaceous when they, as one of the last remaining groups of pterosaurs, became extinct. Although most notable for achieving wingspans comparable with light aircraft, other aspects of azhdarchid morphology and ecology make them not just aberrant animals but also unusual pterosaurs.     

中国东北中生代地层划分对比之新见

在总结近二十年来有关我国东北地区中生代地层研究诸多新发现与新进展的基础上 ,以生物化石为主要依据 ,以 "海相检验法”及国际性生物地层对比为标准 ,结合同位素年代地层学新资料 ,对东北地区中生代地层的划分及对比 ,提出了新的方案。文中还讨论了三叠系 -侏罗系界线、侏罗系 -白垩系界线及下白垩统 -上白垩统界线的划分以及辽西义县组的时代。同时 ,还首次报道了笔者等对黑龙江东部龙爪沟群研究的最新进展 ,并提出了对龙爪沟群时代及与鸡西群对比的新认识。