Vascoceras (Greenhornoceras) birchbyi Cobban & Scott from the Greenhorn Limestone (Lower Turonian) of Central Kansas

The Early Turonian ammonite, Vascoceras (Greenhornoceras) birchbyi Cobban & Scott, has been recorded at nine additional localities in Kansas, Colorado and New Mexico. Most significant is discovery of a specimen in Russell County, Kansas, that doubles the known longitudinal range of the species in the U.S. Western Interior. The species occurs in a single, thin, time-parallel limestone bed that apparently was deposited during a peak pulse of the Cenomanian-Turonian transgression.     

Zalesskioxylon xiaheyanense sp. nov., a gymnospermous wood of the Stephanian (Late Pennsylvanian) from Ningxia, northwestern China

A new Late Pennsylvanian species of gymnospermous fossil wood, Zalesskioxylon xiaheyanense sp. nov. is described from the Lower Taiyuan Formation (Stephanian B-C) near the village of Xiaheyan, Ningxia Hui Autonomous Region, northwestern China. The specimen consists only of silicified secondary xylem. The tracheids are pycnoxylic with 2–3 seriate bordered pits, arranged in subcircular or hexagonal alternate (araucaroid) pattern. The pores of the pits are small, linear, and regularly tilted. Xylem rays are homogeneous, uniseriate, 1–25 cells high. Cross-fields are filled with numerous mixed simple pits of various sizes. Growth rings, axial parenchymatous elements and resin canals are absent. The geographic distribution of Zalesskioxylon woods is reviewed. Zalesskioxylon xiaheyanense sp. nov. grew at low latitudes, and because of the lack of growth rings, probably lived under relatively uniform climatic conditions. Our new species supplements the poorly known distribution of Carboniferous wood in China.     

Amazonsaurus maranhensis gen. et sp. nov. (Sauropoda, Diplodocoidea) from the Lower Cretaceous (Aptian–Albian) of Brazil

A new genus and species of an Aptian–Albian sauropod from the Itapecuru Formation, northern Brazil, Amazonsaurus maranhensis, is described. It is known from an incomplete, but diagnostic postcranial skeleton. The new taxon possesses several autapomorphies, such as the anterior caudal vertebrae with lateral laminae formed by the coalescence of the spinoprezygapophyseal and postzygodiapophyseal laminae and, to a lesser extent, of the postzygodiapophyseal laminae. It exhibits many synapomorphies supporting its inclusion in the Diplodocoidea. These include high caudal neural arches and anterior caudal neural arches with spinoprezygapophyseal laminae on the lateral aspect of the neural spine. This record is consistent with previous hypotheses on the existence of a community of Afro-South American dinosaurs.     

胡氏贵州龙新生个体形态学特征

本文观察并测量了中三叠世拉丁期兴义动物群中的12件包含胚胎的胡氏贵州龙化石及已产出的49个幼体胡氏贵州龙标本;对成年个体与新生个体的体长、肱骨长、股骨长与眼眶长径的特定性状比率关系进行了统计分析;展示了成年个体、胚胎及幼年个体的特征差异,首次描述了胡氏贵州龙新生个体形态学特征;定量刻画了胡氏贵州龙新生个体的头骨、颈椎、背椎、荐椎、尾椎和四肢,获得了更完整、精确的解剖学信息。新材料揭示胡氏贵州龙新生个体的头骨平均长度为8.56mm,肱骨明显短于股骨,肱股比例为1∶1.09。头部呈饱满的三角形,吻部短而钝,眼眶大而圆,具有独特的狭长型上颞孔。此外,研究发现胡氏贵州龙的生产方式为胎儿头部首先从母体产道产出,同时新生个体的吻-臀距稳定在31.04~32.26mm这个数值范围内,且该数值的变动与母体大小无直接联系。本次研究为胡氏贵州龙的生殖方式、个体发育、特别是异速生长研究提供了新的材料。