The first discovery of a dinosaur bone from the Kingdom of Cambodia is reported in this paper. It consists of a sauropod fibula from a sandstone layer on Koh Paur island, in Koh Kong province, in south-western Cambodia. The dinosaur-bearing bed belongs to the non-marine Grès Supérieurs series and is apparently of Early Cretaceous age. On the basis of various characters, notably the development of the anteromedial crest, the dinosaur fibula from Koh Paur is referred to a euhelopodid titanosauriform. This first dinosaur discovery in Cambodia suggests that the thick non-marine formations which cover vast areas in the south-western part of the country are potentially an important source of continental Mesozoic vertebrates.
A fossil of Oniscidea, Tylidae gen. et sp. indet. from Kachin amber (Cretaceous Cenomanian), Myanmar, is described here. The convex body, the cephalon with a triangular protrusion between the antennae, and pereonites 2–6 with epimera demarcated from tergites indicate that this specimen belongs to the family Tylidae, but since it is not an adult the identification of the genus and species is uncertain. This specimen has a convex body and shows an ability to conglobate, like all Tylidae. It is the first specimen of Oniscidea with a conglobation ability found in Burmese amber. Up to now, the fossil record of terrestrial isopods has included a total of 20 families and 54 records (36 species and 18 not formally identified species), 20% of which are from the Cretaceous period. These fossil records from the Cretaceous period show that terrestrial isopods were highly diversified as early as in the Cenomanian.
Mosasaurids, a clade of specialized marine squamates, saw a major adaptive radiation in the Late Cretaceous, evolving a wide range of body sizes, shapes, and specialized tooth morphologies. The most diverse known mosasaurid faunas come from the late Maastrichtian phosphates of Morocco. Here, we report an unusual new mosasaurid, Stelladens mysteriosus, based on a partial jaw and associated tooth crowns from lower Couche III phosphatic deposits at Sidi Chennane, Oulad Abdoun Basin, Morocco. Stelladens is characterized by short, triangular tooth crowns with a series of strong, elaborate, and serrated ridges on the lingual surface of the tooth, functioning as accessory carinae. Morphology of the teeth and associated jaw fragment suggest affinities with Mosasaurinae. No close analogues to the unique tooth morphology of Stelladens are known, either extant or extinct. It may have had an unusual and highly specialized diet, a specialized prey-capture strategy, or both. The diversity of mosasaurid teeth is much higher than that of plesiosaurs, ichthyosaurs, or extant marine mammals, and likely reflects both the ecological diversity of mosasaurids and complex developmental mechanisms responsible for tooth formation in mosasaurines. Mosasaurid diversity continued to increase up to the Cretaceous–Paleogene boundary.
This work explores the swimming of ammonoids, cephalopods related to living squids, octopuses, and nautilids and, like the latter, equipped with a coiled external shell. A mathematical model is introduced for theoretical ammonoid conchs. The two differential equations of motion (one for the centre of mass, including the drag force and the added mass coefficient, and one for the roll angle) are solved numerically for the theoretical conchs, and the results are analysed in terms of velocity and rocking angle. Destabilising resonances occur when the rocking motion is in phase with the propelling water jet. It is suggested that the ammonoids partly evolved avoiding the occurrence of such resonances in their construction.
Mosasaurs were diverse in the Upper Cretaceous in Africa, but relatively little is known about the mosasaur fauna of Egypt. Here, associated teeth and postcranial skeletal elements are reported for a mosasaur from the Maastrichtian Dakhla Shale of the Dakhla Oasis. The specimen includes tooth crowns, cervical, dorsal, and caudal vertebrae, and ribs. Teeth and bones exhibit features allowing referral to Prognathodontini. The teeth are relatively straight and blunt, suggesting affinities with Prognathodon overtoni or P. currii. Prognathodontins were important predators in the Maastrichtian of Africa, previously being recorded in Morocco, Congo, and Angola.
恐龙的食性包括植食性、肉食性和杂食性.植食性恐龙一般体型较大,脑袋较小,牙齿多呈勺状、棒状或片状.我们熟悉的大型蜥脚类恐龙,如梁龙类、腕龙类和巨龙类等都是植食性恐龙.肉食性恐龙的体型差异较大,小到几十厘米,大到十几米,牙齿多呈锋利的匕首状、边缘多发育小锯齿.
很难想象没有马的人类文明史.张骞通西域引入的汗血宝马令无数汉人神往,陪唐·吉诃德大战风车的那匹瘦马让后人无限慨叹,马踏飞燕在河西走廊腾起了历史的烟尘,蒙古铁骑驰骋疆场惊扰了大漠的落日.这些浪漫的传说故事和血迹斑斑的战争史诗,共同书写了马在人类文明史中难以被替代的地位.然而,科技的发展逐渐取代了这种神奇动物在人类社会中的多种功用,在工业革命兴起之后的两百多年时间里,它们也渐渐失去了以往被人类附加的光环.这种骤然衰落的命运,与它们远古祖先的演化轨迹如出一辙.
哈佛大学有多个博物馆,自然博物馆可算其中的佼佼者,每年参观人次超过25万.博物馆成立于1998年,是该校比较动物学博物馆、植物标本馆和矿物与地质博物馆3家研究型博物馆的对外展示窗口.这3家研究型博物馆的历史颇为悠久,且规模在全球名列前茅.如比较动物学博物馆成立于1859年,如今拥有9个学部和超过2100万号标本,其中的古脊椎动物学部便有1000多号正型标本.
2019年4月,《自然》杂志报道了Florent Détroit和Armand Mijares等在菲律宾卡劳洞穴(Callao Cave)发现5万年前人属新种化石,引起学术界的广泛关注.卡劳洞穴遗址坐落在一个被誉为菲律宾"洞穴王国"的城市——菲律宾北部的吕宋岛卡加延(Cagayan)省佩尼亚布兰卡自治市(Peñablanca),城市名字是由两个西班牙语单词组合而成,它的字面意思是"白色的岩石"或"白色的石头",这是因为从远处可以看到,沿着皮纳卡纳万河(Pinacanauan River)畔的山脊上排列着明显的白色石灰岩.
不久前,《国家科学评论》("National Science Review")以封面文章发表了中国科学院古脊椎动物与古人类研究所盖志琨、林翔鸿、山显任与英国布里斯托大学合作完成的九尾狐甲鱼研究成果,并配发了法国科学院院士Philippe Janvier亮点评述文章.
人类自诞生伊始,既在适应不断变化的生态环境,同时又在持续满足本心的内在好奇,他们对未知世界的探索和认知从未停止.15世纪前欧洲人曾认为世界就像一个圆盘,圆盘外则是无尽深渊般的海洋,是不可到达之地,但商路阻隔迫使他们探索地球,催生了航海的技术发展,新航路的开辟成为激动人心的景象.
自组织-生命-进化 "组织"可以定义为系统内的有序结构或有序结构的形成过程.德国理论物理学家赫尔曼·哈肯(H. Haken)将其分为他组织和自组织两类. 他组织是一个系统靠外部指令而形成的组织;如果外部指令不存在,系统以相互默契的某种规律使内部各要素(或子系统)各尽其责而又协调地自动形成有序结构,这就是自组织.
被子植物主导着当今地球陆地生态系统的大部分景观,并在支持不同生态系统的相互作用和包括人类自身的生物多样性构建方面发挥着关键作用.从现代鸟类和植物之间密切关系来看(例如在种子传播、授粉和吸食花蜜机制等),长期以来,鸟类被认为可能在被子植物早期多样性方面扮演着协同演化的重要生态角色.
野外调查对于古生物学的重要意义不言而喻.有道是"巧妇难为无米之炊",没有成功的野外调查,找不到梦寐以求的化石,古生物学研究也就无从谈起.中国地大物博,沉积类型多种多样,在不同的地区开展调查,工作方法也要因地制宜才能行之有效.
确山后胥山隶属驻马店市,位于河南南部,淮河以北.此地喀斯特残丘极为发育,残丘顶面的裂隙中有大量新生代晚期的脊椎动物化石堆积.20世纪40年代始,这里曾发现大量的"龙骨"(哺乳动物化石).20世纪90年代开始,中国科学院古脊椎所金昌柱研究员和河南省文物考古研究所李占杨研究馆员等人在确山后胥山开展地质古生物调查和发掘,1992年,《中国岩溶》初步报道了该地区一些脊椎动物化石名录.
6月11日,由中国古生物化石保护基金会主办的"寻找中国美丽化石"公益盛典在北京举行.活动旨在宣传、推介我国古生物化石科研、科普和文创产品的优秀成果,展示化石的科学和艺术之美,弘扬科学精神,传播科学知识,增强广大公众的化石认知度和保护意识,促进我国古生物化石和自然资源环境保护公益事业高质量发展.
热河生物群的分布区最南可以到什么地方?能到浙江吗?与辽西等地的典型热河生物群有区别吗?带着这样的疑问,我们一行六人在2023年1月前往浙江省衢州市南的石柱岭进行了一次印象深刻的野外化石采集之旅.
泥河湾动物群,即泥河湾早更新世化石哺乳动物群,不仅在中国,而且在东亚地区占有地质古生物重要的学术地位.泥河湾动物群化石的科学调查由巴尔博(George B. Barbour)和桑志华(Émile Licent)开始于1924年9月,同年,巴尔博率先发表了"泥河湾层"(Nihowan beds)的订名,至今已经有100年的历史了,尽管泥河湾动物群的科学研究正式报告是1927年公布的.
