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。     

中国晚侏罗世多瘤齿兽类哺乳动物的发现及其意义

多瘤齿兽是一类已绝灭的哺乳动物,其以后部牙齿上有很多小瘤(小的隆起,或者小尖)来适于咀嚼植物为特征。总的来说,它们的门齿和臼齿与那些啮齿类相似,但在演化时间上多瘤齿兽比新生代的啮齿类早的多。多瘤齿兽是杂食者,或者说是成功开拓了其它脊椎动物无法开拓的植食生境的植食者(可以树叶、种子、蕨类、裸子植物,再加上蠕虫和昆虫为食)。由于它们多种食性和运动方式,多瘤齿兽成为中生代数量最多的哺乳动物,几乎占侏罗纪和白垩纪时期所有哺乳动物种类的一半。它们的支系是哺乳动物历史上生存时间最长的支系,出现于170 Ma前,大约绝灭于35 Ma。但是,因为多瘤齿兽具有很多独特的、高度特化的牙齿和头骨特征,古生物学家们长期困惑于它们的进化起源。最近,中国辽西发现了一件产自晚侏罗世髫髻山组的多瘤齿兽类哺乳动物。由于其牙齿上发育明显的纹饰,如很多小的脊、沟、凹槽等,新发现的哺乳动物被命名为皱纹齿兽(Rugosodon)。另一方面,由于与皱纹齿兽亲缘关系最近的哺乳动物产自西欧的侏罗纪地层,因此其种名被命名为欧亚皱纹齿兽(Rugosodon eurasiaticus)。新发现为晚侏罗世时期欧洲和亚洲的哺乳动物具有高度的相似性提供了最新的证据。皱纹齿兽是一种夜行的哺乳动物,生活于气候温和的湖滨,与长羽毛的恐龙近鸟龙、翼龙类达尔文翼龙、大量节肢动物、其它几种哺乳动物共同生活于一起。根据与现生哺乳动物的比较,并依据欧亚皱纹齿兽手部比例、末端指节的形态等,推论欧亚皱纹齿兽很可能是地栖哺乳动物,或者说地栖比攀爬的可能性更大。这一发现对于研究多瘤齿兽早期的演化、食性分异、运动适应起源等具有重要的科学意义。     

辽西北票地区中-晚侏罗世土城子组恐龙足迹化石的发现

辽西朝阳北票南八家子附近中-晚侏罗世土城子组发现了大量恐龙足迹化石(兽脚类、鸟脚类、蜥脚类).本文主要对兽脚类恐龙足迹做了报道.兽脚类恐龙为两足行走,三趾型、窄行迹、多数为趾行式,化石均为上层面保存.层面发育泥裂和波痕.足迹大小从29.5cm×19cm到4cm×3cm,连续分布的足迹构成明显的行迹,行迹方向规律性分布为当时恐龙的行为习性提供了可靠证据.南八家子地区发现的大量小型兽脚类恐龙足迹表明:在北票地区小型兽脚类恐龙在中晚侏罗世土城子期已经出现.     

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.     

辽西牛营子凹陷中元古界推覆体以下发现早中侏罗世优质烃源岩新地层

【研究目的】一直以来辽西牛营子凹陷油气勘探的目的层为中新元古界。由于构造抬升等因素,该凹陷地表未见辽西其他盆地出露的重要油气勘探层系—侏罗系北票组。【研究方法】本次通过辽凌地1井钻探,在牛营子凹陷中元古界碳酸盐岩推覆体下发现了一套厚层暗色泥岩,对其岩性及孢粉组合特征进行研究,并与辽西北票盆地实测的三宝四坑剖面北票组进行岩性组合对比。【研究结果】证实辽凌地1井中元古界碳酸盐岩推覆体以下厚层泥岩为侏罗系北票组。【结论】有机地球化学指标表明,该泥岩具有有机质丰度高、生烃潜力大的特点,是值得关注的优质烃源岩。该套厚层暗色沉积地层的发现表明侏罗系北票组是牛营子凹陷新的勘探层系,这一认识为研究辽西地区构造演化、油气地质条件提供了重要的基础地质资料。创新点：采用孢粉组合特征及岩性组合特征等方法确定辽凌地1井中元古界推覆体以下暗色泥岩为侏罗系北票组地层,依据地球化学指标确定该套地层为优质烃源岩。     

中国恐头兽类化石与俄罗斯,南非兽孔类动物群的关系

甘肃玉门大山口晚二叠世早期原始恐头兽类化石，与俄罗斯Ⅰ、Ⅱ带和南非Ｅｏｄｉｃｙｎｏｄｏｎ－Ｔａｐｉｎｏｃａｎｉｎｕｓ组合带中Ａｎｔｅｏｓａｕｒｉｄａｅ科的原始属种极其接近，表明当时东亚、东欧、南非之间相互连接或有陆地相通，脊椎动物群可自由交流。     

河南省义马县中侏罗统义马组兽脚类恐龙足印化石的发现及其意义

本文记述了河南省义马县中侏罗世地层中首次发现的大型兽脚类恐龙足印。该足印虽然与发现于下—中侏罗统的张北足印类似,但是又不完全相同,从而命名为该属的一新种:徐氏张北足印(新足迹种):Changpeipus xuianainchnosp. nov.。它具有以下特征:足印的长度与宽度的比率约为1.9,第Ⅱ趾长度稍短于第Ⅳ趾的长度;第Ⅱ和第Ⅲ趾之间的夹角约为25°;第Ⅲ和第Ⅳ趾之间的夹角约为32°,足印的后部具有蹠骨所留下的印痕。徐氏张北足印的发现,不仅为我国中侏罗世恐龙足印增加了新的成员,而且为将来在该地区中侏罗世的地层中发现大型兽脚类恐龙骨骼化石提供确凿的依据。     

代表中国冻土学研究的一个重要里程碑——《中国冻土》一书

冻土是地气之间热量交换的产物, 因此, 冻土对气候的微小变化和变动都非常敏感. 同时, 冻土条件的变化对地气之间水热交换,气候及环境条件,地表径流及地下水, 地气之间的碳循环,植被生长及生态系统, 以及寒区工程建筑都具有重大的影响作用. 研究冻土与环境以及人为活动的相互作用及其反馈效应是全球变化研究的重要内容。     

辽宁中元古代初期粗碎屑岩中微生物砂质颗粒的发现及古环境意义

微生物席成因构造(microbial induced sedimentary structures, MISS)是由微生物与沉积物相互作用形成的生物沉积构造,表现形式有变余波痕、皱饰构造、微生物席碎片、纺锤状或次圆状收缩裂缝等。首次在华北地台东北部辽宁兴城中元古代初期常州沟组底部粗碎屑岩交错层理面上发现了大量的微生物砂质颗粒,在中元古代底部粗碎屑岩中发现大量微生物砂质碎片。这一发现对于了解华北地台MISS的活跃时代以及恢复中元古代早期粗碎屑岩的形成古环境有重要的科学意义,特别是为华北地台古元古代、中元古代的地层划分与对比提供一定的生物地层学参考。发现的微生物砂质颗粒大小在0.1~0.2 mm,形态以球形为主。这些微生物砂质颗粒形成于静水环境的潮上带或泥坪之中的微生物席底,在剧烈的构造运动以及海侵初期高频的海平面运动中被风暴、海啸等灾难性事件破坏,并随着退潮水流被搬运至发育交错层理的潮道区域,与粗碎屑物质一起沉积。这些被风暴破坏的微生物砂质颗粒在搬运过程中被磨圆并产生一定的分选。     

拟刺葵(苦戈维尔叶)亚属Phoenicopsis(Culgoweria)在内蒙古鄂尔多斯盆地中侏罗统的发现

大量茨康类压型化石在鄂尔多斯盆地中侏罗世含煤地层延安组中被发现。本文根据叶外部形态和表皮构造特征,首次发现拟刺葵属的苦戈维尔叶亚属Phoenicopsis(Culgoweria),并建立了鄂尔多斯拟刺葵(苦戈维尔叶)(新种)Phoenicopsis(Culgowaria)ordosensis sp.nov。新种代表了该亚属在我国中侏罗世的第一个化石记录,为研究其地质、地理分布提供了新的证据,也为研究该类植物在欧亚大陆中侏罗世的多样性增添了新内容。     

A New Darwinopterid Pterosaur from the Middle Jurassic of Western Liaoning, Northeastern China and its Ecological Implications

A new species of Darwinopterus, D. robustodens sp. nov. is described and named. Based on the new specimen, the diagnostic characters of Darwinopterus are amended and include: rostral dentition composed of well-spaced, spike-like teeth; the longest teeth are confined to the anterior half of the tooth row; tooth alveoli have raised margins; nasoantorbital fenestra confluent; inclined quadrate; elongate cervical vertebrae with low neural spine and reduced or absent ribs; long tail of more than 20 caudals partially enclosed by filiform extensions of the pre- and postzygapophyses; short metacarpus less than 60 per cent length of humerus, fifth toe with two elongate phalanges and curved second pedal phalanx of the fifth toe with the angle between the proximal and distal segments about 130 degrees. The complete specimen of the new pterosaur D. robustodens sp. nov. provides much more osteological information. The differences in tooth morphologies between Darwinopterus modularis and D. robustodens sp. nov. suggest that they filled different ecological niches. The hard integument-bearing Coleoptera may have been the main food source of Darwinopterus robustodens.     

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.     

Discovery of a New Pterosaur in Western Liaoning,China

The pterosaur from the Yixian Formation in Beipiao, Liaoning Province, ischaracterized by the medium-sized individual, short tail, presence of the gastralia, strongforelimbs, radius and ulna longer than wing-metacarpal, extremely narrow and elongatemetatarsals, degenerated and small phalanx V of hindlimb and so on. It must be a new genusand species, Eosipterus yangi gen. et sp. nov., in the early groups of the SuborderPterodactyloidea. This is the first record of pterosaurs found in Liaoning Province. The fossilprovides new evidence for further determining the nature and geological time of the JeholFauna and for studying the palaeogeography and palaeoenvironment.     

辽宁西部义县组被子植物花粉的首次发现

对辽宁西部晚侏罗世义县组中的孢粉植物群进行了系统研究,首次发现了目前为止世界上最古老的被子植物花粉化石。该花粉植物群可分为三大类,即无孔粉类、原始单远极沟粉类和原始三沟粉类。该发现表明在晚侏罗世原始被子植物已经存在,并且已呈现出多类型特点。义县组中被子植物花粉的新发现为研究被子植物起源问题提供了新的化石依据。     

辽西早白垩世一反鸟类新属种的发现

新反鸟化石（Gracilornis jiufotangensis gen. et sp. nov.）产于辽宁省朝阳地区早白垩世九佛堂组。根据该反鸟的骨骼细弱、肢骨关节发达、胸骨与躯干相比较小（胸骨宽与躯干长比率约为0.11;胸骨长与躯干长比率约为0.13）等不同于其他已知反鸟的特征,建立一新属种,归于华夏鸟科（Cathayornithidae）。     

New Material of Pterosaur Sinopterus （Reptilia： Pterosauria） from the Early Cretaceous Jiufotang Formation, Western Liaoning, China

1 Introduction The Jiufotang Formation is one of the most fossil- productive Early Cretaceous deposits of China. It overlies the famous Yixian Formation from which many important taxa were found (Ji et al., 2004; Chang et al., 2003; Zhou et al., 2003). In addition to other vertebrates, pterosaurs, the first flying reptiles in Earth history, are also abundant in the Jiufotang Formation. At present, nine species belonging to five genera have been reported from the Jiufotang Formation. The…     

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。     

A New Female Cone, Araucaria beipoiaoensis sp. nov. from the Middle Jurassic Tiaojishan Formation, Beipiao, Western Liaoning, China and Its Evolutionary Significance

A new species of Araucaria, Araucaria beipiaoensis sp. nov., collected from the Middle Jurassic Tiaojishan Formation, southern hill of Shebudai village, near Beipiao city, western Liaoning is based on a permineralized female cone, which is ovate to elliptical in shape, about 11 cm × 7 cm × 4.5 cm in size. The cone bears rhomboid bracts that are spirally attached, texture thicker, with wings on both sides, with a detached lamina-like apex at the tip. In inner structure the ovuliferous scales are thicker and fused with bracts at the end with a ligular sulcns. There is one wingless ovule/seed per seed-scale complex embedded in the ovuliferous scale tissue, with the micropyle directed toward the cone axis. The ovules/seeds are long ovate or elliptical in shape, 1 cm long and near the base about 3 mm in diameter; the ovule/seed integuments have begun differentiation into 3 layers： the sarcotesta, sclerotesta, and endotesta. The nucellus is free from the enclosing integuments except in the chalazal region where it is fused to the inner layer （endotesta） of integument. Some ovules show cellularized nucellar tissue. Mature seeds exhibit the papery-thin wavy nucellus characteristically near to the micropyle. The embryonic tissue appears to be four cotyledons. The morphology and structure of the cone shows a close relationship to the araucarian cones of fossil and living genera but differs from any known species. The new species is distributed in the Middle Jurassic of the northern hemisphere, especially Asia, and has important significance for the evolution of the Family Araucariaceae.     

A New Troodontid (Theropoda: Troodontidae) from the Lower Cretaceous Yixian Formation of Western Liaoning, China

A specimen collected from the Lower Cretaceous Yixian Formation of western Liaoning, China, represents a new genus and species of troodontid theropod. The new taxon is named and described on the basis of the holotype and the only known specimen, which comprises an articulated skeleton with the presacral vertebral, shoulder girdle and forelimbs missing as preserved. Diagnostic features of the new species include nasals that are sinusoid in lateral view, absence of a passage connecting the antorbital and maxillary fenestrae, relatively large teeth, plate-like chevrons forming a band along most of the length of the tail, and a long neck between the femoral head and shaft. The temporal constraints of the three paravian groups (Troodontidae, Dromaeosauridae and Aves) combined with the character distributions among the earliest known troodontids indicate a rapid evolution at the base of the Troodontidae.